11/30/2021 – Ephemeris – Previewing December skies

This is Ephemeris for Tuesday, November 30th. Today the Sun will be up for 9 hours and 4 minutes, setting at 5:03, and it will rise tomorrow at 8:00. The Moon, 3 days past last quarter, will rise at 4:24 tomorrow morning.

Let’s look ahead at the skies of December. We are now in the holiday season and about to celebrate the southernmost travel of the Sun in the sky and its return northward. The Sun will stop its travel south, the winter solstice on the 21st at 10:59 a.m. That will make that day the shortest day in terms of daylight hours. However, the earliest sunset and latest sunrise don’t coincide with that date. The reason is the Earth is closer to the Sun than average and is moving faster in its orbit than it normally does. It skews the sunrise and sunset times, making them later than they would be on average. We have a comet, C/2021 A1 (Leonard), that will be bright enough to be visible in binoculars coming into view in the morning later this week and into the next.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). They may be different for your location.

Addendum

December Evening Star Chart

Star Chart for December 2021 (9 p.m. EST December 15, 2021). Click on image to enlarge. Created using my LookingUp program. Click on image to enlarge.

The planets and stars are plotted for the 15th at 9 pm EST in the evening and 6 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT).

December Morning Star Chart

Star Chart for December mornings, 2021 (6 a.m. EST December 15, 2021). Click on image to enlarge. Created using my LookingUp program.

For a list of constellation names to go with the abbreviations click here.

• Pointer stars at the front of the bowl of the Big Dipper point to Polaris, the North Star.
• The leaky bowl of the Big Dipper drips on Leo.
• Follow the arc of the handle of the Big Dipper to the star Arcturus, then
• Follow the spike to Spica.
• The Summer Triangle is in red.
• GemR on the star charts is the radiant of the Geminid meteor shower, which peaks on the morning of the 14th.

Twilight Limits, Nautical and Astronomical

			EST
	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2021-12-01	6h20m	6h56m	18h15m	18h51m	18h51m	4h24m	0.07
2021-12-02	6h21m	6h57m	18h15m	18h50m	18h50m	5h45m	0.02
2021-12-03	6h22m	6h57m	18h15m	18h50m	18h50m	6h22m	0
2021-12-04	6h23m	6h58m	18h15m	18h50m	18h50m	6h23m	0.01
2021-12-05	6h24m	6h59m	18h15m	18h50m	18h50m	6h24m	0.05
2021-12-06	6h25m	7h00m	18h15m	18h50m	19h27m	6h25m	0.12
2021-12-07	6h26m	7h01m	18h15m	18h50m	20h43m	6h26m	0.21
2021-12-08	6h27m	7h02m	18h15m	18h50m	22h00m	6h27m	0.31
2021-12-09	6h28m	7h03m	18h15m	18h50m	23h14m	6h28m	0.41
2021-12-10	6h28m	7h04m	18h15m	18h50m	–	6h28m	0.52
2021-12-11	6h29m	7h05m	18h15m	18h50m	0h25m	6h29m	0.62
2021-12-12	6h30m	7h05m	18h15m	18h51m	1h32m	6h30m	0.71
2021-12-13	6h31m	7h06m	18h15m	18h51m	2h38m	6h31m	0.79
2021-12-14	6h31m	7h07m	18h16m	18h51m	3h42m	6h31m	0.87
2021-12-15	6h32m	7h07m	18h16m	18h51m	4h46m	6h32m	0.92
2021-12-16	6h33m	7h08m	18h16m	18h52m	5h50m	6h33m	0.97
2021-12-17	6h29m	7h05m	18h13m	18h48m	–	–	0.99
2021-12-18	6h30m	7h05m	18h13m	18h48m	–	–	1
2021-12-19	6h30m	7h06m	18h13m	18h49m	–	–	0.99
2021-12-20	6h31m	7h07m	18h14m	18h49m	–	–	0.96
2021-12-21	6h31m	7h07m	18h14m	18h50m	18h50m	19h11m	0.92
2021-12-22	6h32m	7h07m	18h15m	18h50m	18h50m	20h16m	0.86
2021-12-23	6h32m	7h08m	18h15m	18h51m	18h51m	21h23m	0.78
2021-12-24	6h33m	7h08m	18h16m	18h51m	18h51m	22h31m	0.7
2021-12-25	6h33m	7h09m	18h17m	18h52m	18h52m	23h40m	0.6
2021-12-26	6h34m	7h09m	18h17m	18h53m	18h53m	–	0.49
2021-12-27	6h34m	7h09m	18h18m	18h53m	18h53m	0h50m	0.38
2021-12-28	6h34m	7h10m	18h19m	18h54m	18h54m	2h02m	0.27
2021-12-29	6h34m	7h10m	18h19m	18h55m	18h55m	3h18m	0.18
2021-12-30	6h35m	7h10m	18h20m	18h55m	18h55m	4h38m	0.1
2021-12-31	6h35m	7h10m	18h21m	18h56m	18h56m	6h00m	0.04

Twilight calendar was generated using Cartes du Ciel (Sky Charts).

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

     Date     Time    Event
Dec  1  We            Venus: 41.4° E
     3  Fr   9:58 am  Moon Descending Node
     4  Sa   2:34 am  Total Solar Eclipse (Antarctica, Southern Ocean)
     4  Sa   2:43 am  New Moon
     4  Sa   5:01 am  Moon Perigee: 356800 km
     5  Su   9:25 pm  Moon South Dec.: 26.3° S
     6  Mo   7:48 pm  Moon-Venus: 1.9° N
     7  Tu   8:52 pm  Moon-Saturn: 4.2° N
     9  Th   1:07 am  Moon-Jupiter: 4.6° N
    10  Fr   8:36 pm  First Quarter
    14  Tu   1:44 am  Geminid Shower: ZHR = 120
    16  Th   7:12 pm  Moon Ascending Node
    17  Fr   9:16 pm  Moon Apogee: 406300 km
    18  Sa  11:36 pm  Full Moon
    19  Su  11:32 pm  Moon North Dec.: 26.3° N
    21  Tu   4:20 am  Moon-Pollux: 2.9° N
    21  Tu  10:59 am  Winter Solstice
    22  We   5:28 am  Moon-Beehive: 3.6° S
    22  We  10:00 am  Ursid Shower: ZHR = 10
    26  Su   9:24 pm  Last Quarter
    27  Mo   4:17 am  Mars-Antares: 4.5° N
    28  Tu  11:49 pm  Mercury-Venus: 4.2° N
    30  Th   8:07 pm  Moon Descending Node
    31  Fr   3:13 pm  Moon-Mars: 0.9° N

All event times are given for UTC-5 Eastern Standard Time.

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

If you go to the above site, you can print out a list like the above for the entire year or calendar pages for your time zone.

Sun and Moon Rising and Setting Events

LU                  Ephemeris of Sky Events for Interlochen/TC
December, 2021    Local time zone: EST
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Wed  1| 08:00a  05:03p  09:03 | 06:12p  06:50a |      Rise 05:45a    8%|
|Thu  2| 08:01a  05:03p  09:01 | 06:12p  06:51a |      Rise 07:09a    3%|
|Fri  3| 08:02a  05:02p  09:00 | 06:12p  06:52a |      Rise 08:33a    0%|
|Sat  4| 08:03a  05:02p  08:59 | 06:12p  06:53a |New   Set  05:18p    1%|
+------+-----------------------+----------------+-----------------------+
|Sun  5| 08:04a  05:02p  08:57 | 06:12p  06:54a |      Set  06:17p    4%|
|Mon  6| 08:05a  05:02p  08:56 | 06:12p  06:55a |      Set  07:27p   11%|
|Tue  7| 08:06a  05:02p  08:55 | 06:12p  06:56a |      Set  08:43p   19%|
|Wed  8| 08:07a  05:02p  08:54 | 06:12p  06:57a |      Set  10:00p   28%|
|Thu  9| 08:08a  05:02p  08:53 | 06:12p  06:58a |      Set  11:14p   39%|
|Fri 10| 08:09a  05:02p  08:52 | 06:12p  06:59a |F Qtr Set  12:25a   49%|
|Sat 11| 08:10a  05:02p  08:51 | 06:12p  06:59a |      Set  01:32a   60%|
+------+-----------------------+----------------+-----------------------+
|Sun 12| 08:11a  05:02p  08:51 | 06:12p  07:00a |      Set  02:37a   69%|
|Mon 13| 08:11a  05:02p  08:50 | 06:12p  07:01a |      Set  03:41a   78%|
|Tue 14| 08:12a  05:02p  08:49 | 06:13p  07:02a |      Set  04:45a   85%|
|Wed 15| 08:13a  05:02p  08:49 | 06:13p  07:02a |      Set  05:50a   91%|
|Thu 16| 08:14a  05:03p  08:49 | 06:13p  07:03a |      Set  06:53a   96%|
|Fri 17| 08:14a  05:03p  08:48 | 06:14p  07:04a |      Set  07:56a   99%|
|Sat 18| 08:15a  05:03p  08:48 | 06:14p  07:04a |Full  Rise 04:34p  100%|
+------+-----------------------+----------------+-----------------------+
|Sun 19| 08:16a  05:04p  08:48 | 06:14p  07:05a |      Rise 05:19p   99%|
|Mon 20| 08:16a  05:04p  08:48 | 06:15p  07:05a |      Rise 06:12p   97%|
|Tue 21| 08:17a  05:05p  08:48 | 06:15p  07:06a |      Rise 07:11p   93%|
|Wed 22| 08:17a  05:05p  08:48 | 06:16p  07:06a |      Rise 08:16p   87%|
|Thu 23| 08:18a  05:06p  08:48 | 06:16p  07:07a |      Rise 09:23p   80%|
|Fri 24| 08:18a  05:06p  08:48 | 06:17p  07:07a |      Rise 10:31p   71%|
|Sat 25| 08:18a  05:07p  08:48 | 06:18p  07:08a |      Rise 11:40p   62%|
+------+-----------------------+----------------+-----------------------+
|Sun 26| 08:19a  05:08p  08:49 | 06:18p  07:08a |L Qtr Rise 12:50a   51%|
|Mon 27| 08:19a  05:08p  08:49 | 06:19p  07:08a |      Rise 02:02a   40%|
|Tue 28| 08:19a  05:09p  08:50 | 06:20p  07:09a |      Rise 03:18a   30%|
|Wed 29| 08:19a  05:10p  08:50 | 06:20p  07:09a |      Rise 04:37a   20%|
|Thu 30| 08:19a  05:11p  08:51 | 06:21p  07:09a |      Rise 06:00a   11%|
|Fri 31| 08:20a  05:12p  08:52 | 06:22p  07:09a |      Rise 07:20a    5%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

Comet Leonard

Comet Leonard’s positions at 6:30 am on the dates indicated. The labels are Month-Day Total Magnitude. The star’s position relative to the horizon and the position of Mars are for November 27th. The star field will be shifting to the upper right each morning at 6:30 from the November 27th date. Comets always appear dimmer than their magnitude suggests because they are extended objects, not points like stars. Also, comet magnitudes can be unpredictable. Plus, the comet tails will not appear as long. The tail may not actually be visible visually. Created using Cartes du Ciel (Sky Charts). Reprinted from my article in the December 2021 issue of the Stellar Sentinel, the newsletter for the Grand Traverse Astronomical Society.

This is our best shot at spotting the comet. After it passes the Sun and enters the evening sky, the comet will hug the southwest to southern horizon in twilight. I’ll have more on Comet Leonard in the rest of the programs this week.

11/01/2021 – Ephemeris – Previewing November skies

This is Ephemeris for Monday, November 1st. The Sun will rise at 8:21. It’ll be up for 10 hours and 9 minutes, setting at 6:31. The Moon, 3 days before new, will rise at 5:18 tomorrow morning.

Let’s look ahead at the skies for the month of November. The Sun is still moving south rapidly at the beginning of the month, but will slow down toward the end. Daylight hours in the Interlochen/Traverse City area and will drop from 10 hours and 9 minutes today to 9 hours 4 minutes on the 30th. The altitude, or angle, of the Sun above the southern horizon at local noon will be at 30 degrees tomorrow and will descend to 23 and a half degrees on the 30th. The altitude of the Sun in the Straits area will be a degree lower. Local noon, this month, is about 12:30 p.m. There will be an almost total eclipse of the Moon on the morning of Friday the 19th. The eclipse will start at 2:18 am. Mid-eclipse with a tiny sliver of the Moon in sunlight will be at 4:05 am. It all ends at 5:47 am.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

November Evening Star Chart

Star Chart for November evenings, 2021 (9 p.m. EST November 15, 2019). Click on image to enlarge. Click on image to enlarge. Created using my LookingUp program.

November Morning Star Chart

Star Chart for November mornings, 2021 (6 a.m. EST November 15, 2020). Click on image to enlarge. Created using my LookingUp program.

For a list of constellation names to go with the abbreviations, click here.

• Pointer stars at the front of the bowl of the Big Dipper point to Polaris, the North Star.
• Follow the arc of the handle of the Big Dipper to the star Arcturus
• The Summer Triangle is in red.
• TauR on the evening star chart can be used as the radiant for the North and South Taurid meteor showers.
• LeoR on the morning star chart is the radiant of the Leonid meteor shower, which peaks between the 17th.

Twilight Limits, Nautical and Astronomical

			EDT
	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2021-11-01	6h47m	7h21m	19h39m	20h13m	20h13m	4h03m	0.1
2021-11-02	6h48m	7h22m	19h38m	20h12m	20h12m	5h18m	0.04
2021-11-03	6h49m	7h23m	19h36m	20h10m	20h10m	6h36m	0.01
2021-11-04	6h51m	7h25m	19h35m	20h09m	20h09m	6h51m	0
2021-11-05	6h52m	7h26m	19h34m	20h08m	20h08m	6h52m	0.03
2021-11-06	6h53m	7h27m	19h33m	20h07m	20h07m	6h53m	0.08
2021-11-07	5h54m	6h28m	18h32m	19h06m	19h35m	5h54m	0.15
2021-11-08	5h55m	6h30m	18h31m	19h05m	20h37m	5h55m	0.25
2021-11-09	5h57m	6h31m	18h30m	19h04m	21h48m	5h57m	0.36
2021-11-10	5h58m	6h32m	18h29m	19h03m	23h02m	5h58m	0.47
2021-11-11	5h59m	6h33m	18h28m	19h02m	–	5h59m	0.57
2021-11-12	6h00m	6h34m	18h27m	19h01m	0h16m	6h00m	0.68
2021-11-13	6h01m	6h36m	18h26m	19h00m	1h27m	6h01m	0.77
2021-11-14	6h02m	6h37m	18h25m	18h59m	2h35m	6h02m	0.85
2021-11-15	6h03m	6h38m	18h24m	18h59m	3h41m	6h03m	0.91
2021-11-16	6h05m	6h39m	18h23m	18h58m	4h45m	6h05m	0.96
2021-11-17	6h06m	6h40m	18h23m	18h57m	5h50m	6h06m	0.99
2021-11-18	6h07m	6h41m	18h22m	18h56m	–	–	1
2021-11-19	6h08m	6h43m	18h21m	18h56m	–	–	0.99
2021-11-20	6h09m	6h44m	18h20m	18h55m	–	–	0.97
2021-11-21	6h10m	6h45m	18h20m	18h54m	–	–	0.93
2021-11-22	6h11m	6h46m	18h19m	18h54m	18h54m	19h22m	0.87
2021-11-23	6h12m	6h47m	18h19m	18h53m	18h53m	20h17m	0.81
2021-11-24	6h13m	6h48m	18h18m	18h53m	18h53m	21h19m	0.72
2021-11-25	6h14m	6h49m	18h18m	18h52m	18h52m	22h24m	0.63
2021-11-26	6h15m	6h50m	18h17m	18h52m	18h52m	23h33m	0.53
2021-11-27	6h16m	6h51m	18h17m	18h52m	18h52m	–	0.43
2021-11-28	6h17m	6h52m	18h16m	18h51m	18h51m	0h43m	0.33
2021-11-29	6h18m	6h54m	18h16m	18h51m	18h51m	1h54m	0.23
2021-11-30	6h19m	6h55m	18h16m	18h51m	18h51m	3h07m	0.14

Twilight calendar was generated using Cartes du Ciel (Sky Charts).

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

   Date      Time    Event
Nov  1  Mo            Venus: 47° E
     1  Mo   8:17 pm  Mercury-Spica: 4.1° N
     4  Th   4:15 pm  New Moon
     4  Th   7:13 pm  Uranus Opposition
     5  Fr   5:23 pm  Moon Perigee: 358800 km
     5  Fr  10:38 pm  Moon Descending Node
     8  Mo  12:21 am  Moon-Venus: 1.1° S
     8  Mo  11:27 am  Moon South Dec.: 26.3° S
    10  We   9:27 am  Moon-Saturn: 4.2° N
    11  Th   7:46 am  First Quarter
    11  Th  12:12 pm  Moon-Jupiter: 4.5° N
    12  Fr   6:16 am  North Taurid Shower: ZHR = 15
    17  We  12:33 pm  Leonid Shower: ZHR = 15
    19  Fr   3:58 am  Full Moon
    19  Fr   4:04 am  Partial Lunar Eclipse
    19  Fr  12:59 pm  Moon Ascending Node
    20  Sa   9:14 pm  Moon Apogee: 406300 km
    22  Mo   5:43 pm  Moon North Dec.: 26.3° N
    23  Tu  10:22 pm  Moon-Pollux: 2.8° N
    24  We  11:32 pm  Moon-Beehive: 3.6° S
    27  Sa   7:28 am  Last Quarter
    28  Su  11:35 pm  Mercury Superior Solar Conj.

All event times for November 1-6 are given for UTC-4 Eastern Daylight Saving Time. Dates after that times are given for UTC-5 Eastern Standard Time.

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

If you go to the above site you can print out a list like the above for the entire year or calendar pages for your time zone.

Sun and Moon Rising and Setting Events

LU             Ephemeris of Sky Events for Interlochen/TC
November, 2021    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Mon  1| 08:21a  06:31p  10:09 | 07:36p  07:16a |      Rise 05:18a   11%|
|Tue  2| 08:22a  06:29p  10:07 | 07:34p  07:17a |      Rise 06:35a    5%|
|Wed  3| 08:23a  06:28p  10:04 | 07:33p  07:18a |      Rise 07:56a    1%|
|Thu  4| 08:25a  06:26p  10:01 | 07:32p  07:19a |New   Set  06:31p    0%|
|Fri  5| 08:26a  06:25p  09:59 | 07:31p  07:21a |      Set  07:04p    2%|
|Sat  6| 08:27a  06:24p  09:56 | 07:30p  07:22a |      Set  07:44p    7%|
+------+-----------------------+----------------+-----------------------+
| EST  |      Time Change      |                |                       |
|Sun  7| 07:29a  05:23p  09:53 | 06:28p  06:23a |      Set  07:35p   14%|
|Mon  8| 07:30a  05:21p  09:51 | 06:27p  06:24a |      Set  08:37p   23%|
|Tue  9| 07:32a  05:20p  09:48 | 06:26p  06:25a |      Set  09:48p   33%|
|Wed 10| 07:33a  05:19p  09:46 | 06:25p  06:27a |      Set  11:02p   44%|
|Thu 11| 07:34a  05:18p  09:43 | 06:24p  06:28a |F Qtr Set  12:16a   55%|
|Fri 12| 07:36a  05:17p  09:41 | 06:24p  06:29a |      Set  01:27a   65%|
|Sat 13| 07:37a  05:16p  09:38 | 06:23p  06:30a |      Set  02:35a   75%|
+------+-----------------------+----------------+-----------------------+
|Sun 14| 07:38a  05:15p  09:36 | 06:22p  06:31a |      Set  03:40a   83%|
|Mon 15| 07:40a  05:14p  09:34 | 06:21p  06:33a |      Set  04:45a   90%|
|Tue 16| 07:41a  05:13p  09:31 | 06:20p  06:34a |      Set  05:49a   95%|
|Wed 17| 07:42a  05:12p  09:29 | 06:19p  06:35a |      Set  06:54a   98%|
|Thu 18| 07:44a  05:11p  09:27 | 06:19p  06:36a |      Set  07:58a  100%|
|Fri 19| 07:45a  05:10p  09:25 | 06:18p  06:37a |Full  Rise 05:23p  100%|
|Sat 20| 07:46a  05:09p  09:23 | 06:17p  06:38a |      Rise 05:56p   98%|
+------+-----------------------+----------------+-----------------------+
|Sun 21| 07:48a  05:09p  09:21 | 06:17p  06:40a |      Rise 06:35p   94%|
|Mon 22| 07:49a  05:08p  09:19 | 06:16p  06:41a |      Rise 07:22p   89%|
|Tue 23| 07:50a  05:07p  09:17 | 06:15p  06:42a |      Rise 08:17p   82%|
|Wed 24| 07:51a  05:07p  09:15 | 06:15p  06:43a |      Rise 09:19p   74%|
|Thu 25| 07:53a  05:06p  09:13 | 06:15p  06:44a |      Rise 10:24p   65%|
|Fri 26| 07:54a  05:05p  09:11 | 06:14p  06:45a |      Rise 11:33p   55%|
|Sat 27| 07:55a  05:05p  09:09 | 06:14p  06:46a |L Qtr Rise 12:42a   45%|
+------+-----------------------+----------------+-----------------------+
|Sun 28| 07:56a  05:04p  09:08 | 06:13p  06:47a |      Rise 01:54a   35%|
|Mon 29| 07:57a  05:04p  09:06 | 06:13p  06:48a |      Rise 03:07a   25%|
|Tue 30| 07:59a  05:03p  09:04 | 06:13p  06:49a |      Rise 04:24a   15%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

Preview of the November 19, 2021 partial lunar eclipse at maximum at 4:05 am

A Stellarium simulation of what the partial lunar eclipse of the 19th might look like at its peak at 4:05 am EST.

09/30/2021 – Ephemeris – Previewing October skies

This is Ephemeris for Thursday, September 30th. Today the Sun will be up for 11 hours and 44 minutes, setting at 7:24, and it will rise tomorrow at 7:41. The Moon, 2 days past last quarter, will rise at 1:42 tomorrow morning.

Let’s look at the skies for this month of October. The Sun will still be moving south rapidly. Daylight hours in the Interlochen/Traverse City area will drop from 11 hours and 41 minutes tomorrow to 10 hours 12 minutes on the 31st. The altitude of the sun above the southern horizon at local noon will be 42 degrees tomorrow, and will descend to 31 degrees on Halloween, also in the Interlochen/Traverse City area. The Straits area will have the sun a degree lower. Local noon, when the Sun is due south, will be about 1:30 pm in Interlochen and Traverse City. Bits of Halley’s comet will return later in the month as the Orionid meteor shower. However, it will have to compete with a nearly full moon.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT-4 hours). They may be different for your location.

October Evening Star Chart

Star Chart for October 2021. (9 p.m. EDT, October 15, 2021) Click on image to enlarge. Created using my LookingUp program. Click on image to enlarge.

The planets and stars are plotted for the 15th at 9 p.m. EDT in the evening and 6 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.

October Morning Star Chart

Star Chart for October mornings, 2021 (6 a.m. EDT, October 15, 2021). Click on image to enlarge. Created using my LookingUp program.

For a list of constellation names to go with the abbreviations, click here.

• Pointer stars at the front of the bowl of the Big Dipper point to Polaris, the North Star.
• Leaky dipper drips on Leo.
• Follow the arc of the handle of the Big Dipper to the star Arcturus.
• The Summer Triangle is in red.
• OriR – Orionid Radiant – Peak 22nd – Zenithal Hourly Rate = 20

Twilight Limits, Nautical and Astronomical

			EDT
	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2021-10-01	6h09m	6h43m	20h29m	21h03m	21h03m	1h42m	0.21
2021-10-02	6h10m	6h44m	20h27m	21h01m	21h01m	2h49m	0.13
2021-10-03	6h11m	6h45m	20h25m	20h59m	20h59m	4h01m	0.07
2021-10-04	6h13m	6h47m	20h23m	20h57m	20h57m	5h15m	0.02
2021-10-05	6h14m	6h48m	20h21m	20h55m	20h55m	6h14m	0
2021-10-06	6h15m	6h49m	20h19m	20h54m	20h54m	6h15m	0.01
2021-10-07	6h16m	6h50m	20h18m	20h52m	20h52m	6h16m	0.04
2021-10-08	6h18m	6h52m	20h16m	20h50m	20h50m	6h18m	0.1
2021-10-09	6h19m	6h53m	20h14m	20h48m	21h10m	6h19m	0.19
2021-10-10	6h20m	6h54m	20h12m	20h46m	21h53m	6h20m	0.29
2021-10-11	6h21m	6h55m	20h11m	20h44m	22h46m	6h21m	0.4
2021-10-12	6h23m	6h57m	20h09m	20h43m	23h50m	6h23m	0.51
2021-10-13	6h24m	6h58m	20h07m	20h41m	–	6h24m	0.62
2021-10-14	6h25m	6h59m	20h06m	20h39m	1h00m	6h25m	0.72
2021-10-15	6h26m	7h00m	20h04m	20h38m	2h13m	6h26m	0.81
2021-10-16	6h28m	7h01m	20h02m	20h36m	3h25m	6h28m	0.89
2021-10-17	6h29m	7h03m	20h01m	20h34m	4h35m	6h29m	0.94
2021-10-18	6h30m	7h04m	19h59m	20h33m	5h43m	6h30m	0.98
2021-10-19	6h31m	7h05m	19h57m	20h31m	–	–	1
2021-10-20	6h33m	7h06m	19h56m	20h30m	–	–	1
2021-10-21	6h34m	7h08m	19h54m	20h28m	–	–	0.98
2021-10-22	6h35m	7h09m	19h53m	20h26m	–	–	0.94
2021-10-23	6h36m	7h10m	19h51m	20h25m	–	–	0.89
2021-10-24	6h37m	7h11m	19h50m	20h24m	20h24m	20h56m	0.82
2021-10-25	6h39m	7h12m	19h48m	20h22m	20h22m	21h38m	0.74
2021-10-26	6h40m	7h14m	19h47m	20h21m	20h21m	22h29m	0.66
2021-10-27	6h41m	7h15m	19h45m	20h19m	20h19m	23h27m	0.56
2021-10-28	6h42m	7h16m	19h44m	20h18m	20h18m	–	0.46
2021-10-29	6h43m	7h17m	19h43m	20h17m	20h17m	0h31m	0.37
2021-10-30	6h45m	7h19m	19h41m	20h15m	20h15m	1h39m	0.27
2021-10-31	6h46m	7h20m	19h40m	20h14m	20h14m	2h50m	0.18

Twilight calendar was generated using Cartes du Ciel (Sky Charts).

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

Date         Time ET  Event
Oct  1  Fr            Venus: 44.9° E
     1  Fr   9:08 am  Moon-Beehive: 3.3° S
     6  We   7:05 am  New Moon
     7  Th  11:50 pm  Mars Solar Conjunction
     8  Fr   1:28 pm  Moon Perigee: 363400 km
     9  Sa  12:12 pm  Mercury Inferior Conj.
     9  Sa   2:36 pm  Moon-Venus: 2.9° S
     9  Sa   3:35 pm  Moon Descending Node
    10  Su            S Taurid peak ZHR = 5 See IMO Calendar
    12  Tu   5:09 am  Moon South Dec.: 26.2° S
    12  Tu  11:25 pm  First Quarter
    14  Th   3:12 am  Moon-Saturn: 4.1° N
    15  Fr   5:58 am  Moon-Jupiter: 4.3° N
    16  Sa   9:24 am  Venus-Antares: 1.5° N
    20  We  10:57 am  Full Moon
    21  Th   7:30 am  Orionid Shower: ZHR = 20
    23  Sa   7:47 am  Moon Ascending Node
    24  Su  11:30 am  Moon Apogee: 405600 km
    25  Mo  12:59 am  Mercury Greatest Elongation: 18.4° W
    26  Tu  12:04 pm  Moon North Dec.: 26.3° N
    27  We   4:40 pm  Moon-Pollux: 2.8° N
    28  Th   4:05 pm  Last Quarter
    28  Th   5:32 pm  Moon-Beehive: 3.6° S
    29  Fr   5:59 pm  Venus Greatest Elongation: 47° E
Nov  1  Mo            Venus: 47° E

All event times are given for UTC-4 hr: Eastern Daylight Saving Time.

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

If you go to the above site, you can print out a list like the above for the entire year or calendar pages for your time zone.

Sun and Moon Rising and Setting Events

LU                  Ephemeris of Sky Events for Interlochen/TC
October, 2021    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Fri  1| 07:41a  07:22p  11:41 | 08:25p  06:38a |      Rise 02:49a   23%|
|Sat  2| 07:42a  07:20p  11:38 | 08:23p  06:39a |      Rise 04:01a   15%|
+------+-----------------------+----------------+-----------------------+
|Sun  3| 07:43a  07:19p  11:35 | 08:21p  06:40a |      Rise 05:15a    8%|
|Mon  4| 07:44a  07:17p  11:32 | 08:20p  06:41a |      Rise 06:30a    3%|
|Tue  5| 07:46a  07:15p  11:29 | 08:18p  06:43a |      Rise 07:46a    0%|
|Wed  6| 07:47a  07:13p  11:26 | 08:16p  06:44a |New   Set  07:41p    0%|
|Thu  7| 07:48a  07:11p  11:23 | 08:14p  06:45a |      Set  08:06p    3%|
|Fri  8| 07:49a  07:09p  11:20 | 08:12p  06:46a |      Set  08:35p    9%|
|Sat  9| 07:51a  07:08p  11:17 | 08:11p  06:47a |      Set  09:09p   17%|
+------+-----------------------+----------------+-----------------------+
|Sun 10| 07:52a  07:06p  11:14 | 08:09p  06:49a |      Set  09:53p   26%|
|Mon 11| 07:53a  07:04p  11:11 | 08:07p  06:50a |      Set  10:46p   37%|
|Tue 12| 07:54a  07:02p  11:08 | 08:05p  06:51a |F Qtr Set  11:50p   48%|
|Wed 13| 07:56a  07:01p  11:05 | 08:04p  06:52a |      Set  01:00a   59%|
|Thu 14| 07:57a  06:59p  11:02 | 08:02p  06:54a |      Set  02:13a   70%|
|Fri 15| 07:58a  06:57p  10:59 | 08:00p  06:55a |      Set  03:25a   79%|
|Sat 16| 07:59a  06:55p  10:56 | 07:59p  06:56a |      Set  04:35a   87%|
+------+-----------------------+----------------+-----------------------+
|Sun 17| 08:01a  06:54p  10:53 | 07:57p  06:57a |      Set  05:43a   93%|
|Mon 18| 08:02a  06:52p  10:50 | 07:56p  06:58a |      Set  06:49a   97%|
|Tue 19| 08:03a  06:50p  10:47 | 07:54p  07:00a |      Set  07:54a  100%|
|Wed 20| 08:05a  06:49p  10:44 | 07:52p  07:01a |Full  Rise 07:07p  100%|
|Thu 21| 08:06a  06:47p  10:41 | 07:51p  07:02a |      Rise 07:29p   98%|
|Fri 22| 08:07a  06:46p  10:38 | 07:49p  07:03a |      Rise 07:53p   95%|
|Sat 23| 08:09a  06:44p  10:35 | 07:48p  07:05a |      Rise 08:22p   90%|
+------+-----------------------+----------------+-----------------------+
|Sun 24| 08:10a  06:42p  10:32 | 07:46p  07:06a |      Rise 08:56p   84%|
|Mon 25| 08:11a  06:41p  10:29 | 07:45p  07:07a |      Rise 09:38p   76%|
|Tue 26| 08:13a  06:39p  10:26 | 07:44p  07:08a |      Rise 10:29p   67%|
|Wed 27| 08:14a  06:38p  10:23 | 07:42p  07:10a |      Rise 11:27p   58%|
|Thu 28| 08:15a  06:36p  10:21 | 07:41p  07:11a |L Qtr Rise 12:31a   48%|
|Fri 29| 08:17a  06:35p  10:18 | 07:39p  07:12a |      Rise 01:39a   38%|
|Sat 30| 08:18a  06:33p  10:15 | 07:38p  07:13a |      Rise 02:50a   29%|
+------+-----------------------+----------------+-----------------------+
|Sun 31| 08:19a  06:32p  10:12 | 07:37p  07:14a |      Rise 04:03a   19%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

08/31/2021 – Ephemeris – Previewing September skies

This is Bob Moler with Ephemeris for Tuesday, August 31st. Today the Sun will be up for 13 hours and 16 minutes, setting at 8:20, and it will rise tomorrow at 7:05. The Moon, 1 day past last quarter, will rise at 1:07 tomorrow morning.

Let’s look at the skies for the month of September. The sun will be moving at its greatest speed in its retreat to the south. Daylight hours in the Interlochen/Traverse City area and will drop from 13 hours and 13 minutes tomorrow to 11 hours and 44 minutes on the 30th. The altitude of the Sun above the southern horizon at local noon will be 54 degrees tomorrow, and will descend to 42 degrees on the 30th. Local noon at mid-month will be around 1:37 pm. The season of summer is getting short, so enjoy it while you can. Summer ends and autumn begins at 3:21 p.m. on September 22nd, the autumnal equinox. This year the Harvest Moon, the nearest full moon to the equinox, will fall two days before it on the 20th.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.

Addendum

September Star Chart

Star Chart for September 2021. Created using my LookingUp program. Click on the image to enlarge it. Created using my LookingUp program.

The planets and stars are plotted for the 15th at 10 p.m. EDT in the evening and 6 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.

September Morning Star Chart

Star Chart for September 2021 (10 p.m. EDT, September 15, 2021). Click on the image to enlarge it. Created using my LookingUp program.

For a list of constellation names to go with the abbreviations, click here.

• Pointer stars at the front of the bowl of the Big Dipper point to Polaris, the North Star.
• Leaky dipper drips on Leo.
• Follow the arc of the handle of the Big Dipper to the star Arcturus.
• The Summer Triangle is in red.

Twilight Limits, Nautical and Astronomical

			EDT
	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2021-09-01	5h26m	6h04m	21h28m	22h06m	22h06m	1h07m	0.24
2021-09-02	5h28m	6h06m	21h26m	22h04m	22h04m	1h57m	0.16
2021-09-03	5h29m	6h07m	21h24m	22h02m	22h02m	2h55m	0.09
2021-09-04	5h31m	6h08m	21h22m	22h00m	22h00m	4h01m	0.04
2021-09-05	5h32m	6h10m	21h20m	21h57m	21h57m	5h11m	0.01
2021-09-06	5h34m	6h11m	21h18m	21h55m	21h55m	5h34m	0
2021-09-07	5h35m	6h12m	21h16m	21h53m	21h53m	5h35m	0.02
2021-09-08	5h37m	6h14m	21h14m	21h51m	21h51m	5h37m	0.06
2021-09-09	5h38m	6h15m	21h12m	21h49m	21h49m	5h38m	0.13
2021-09-10	5h40m	6h16m	21h10m	21h46m	22h06m	5h40m	0.21
2021-09-11	5h41m	6h18m	21h08m	21h44m	22h35m	5h41m	0.32
2021-09-12	5h43m	6h19m	21h06m	21h42m	23h12m	5h43m	0.43
2021-09-13	5h44m	6h20m	21h04m	21h40m	23h57m	5h44m	0.54
2021-09-14	5h46m	6h22m	21h02m	21h38m	–	5h46m	0.65
2021-09-15	5h47m	6h23m	21h00m	21h36m	0h53m	5h47m	0.76
2021-09-16	5h48m	6h24m	20h58m	21h34m	1h59m	5h48m	0.84
2021-09-17	5h50m	6h25m	20h56m	21h31m	3h10m	5h50m	0.91
2021-09-18	5h51m	6h27m	20h54m	21h29m	4h24m	5h51m	0.96
2021-09-19	5h53m	6h28m	20h52m	21h27m	5h37m	5h53m	0.99
2021-09-20	5h54m	6h29m	20h50m	21h25m	–	–	1
2021-09-21	5h55m	6h31m	20h48m	21h23m	–	–	0.99
2021-09-22	5h57m	6h32m	20h46m	21h21m	–	–	0.95
2021-09-23	5h58m	6h33m	20h44m	21h19m	–	–	0.9
2021-09-24	6h00m	6h34m	20h42m	21h17m	21h17m	21h26m	0.84
2021-09-25	6h01m	6h36m	20h40m	21h15m	21h15m	21h52m	0.76
2021-09-26	6h02m	6h37m	20h38m	21h13m	21h13m	22h23m	0.67
2021-09-27	6h04m	6h38m	20h36m	21h11m	21h11m	23h00m	0.58
2021-09-28	6h05m	6h39m	20h34m	21h09m	21h09m	23h46m	0.49
2021-09-29	6h06m	6h41m	20h32m	21h07m	21h07m	–	0.39
2021-09-30	6h07m	6h42m	20h31m	21h05m	21h05m	0h40m	0.3

Twilight calendar was generated using Cartes du Ciel (Sky Charts).

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

Sep  1  We            Venus: 39.9° E
     1  We   8:23 pm  Moon North Dec.: 25.9° N
     4  Sa  12:07 am  Moon-Beehive: 3.1° S
     5  Su  10:32 am  Venus-Spica: 1.6° N
     6  Mo   8:52 pm  New Moon
     9  Th  10:09 pm  Moon-Venus: 4.1° S
    11  Sa   6:06 am  Moon Perigee: 368500 km
    12  Su  12:35 pm  Moon Descending Node
    13  Mo   4:39 pm  First Quarter
    13  Mo  11:59 pm  Mercury Elongation: 26.8° E
    14  Tu   4:10 am  Neptune Opposition
    14  Tu  11:48 pm  Moon South Dec.: 26° S
    16  Th  10:37 pm  Moon-Saturn: 3.9° N
    18  Sa   2:50 am  Moon-Jupiter: 4.1° N
    20  Mo   7:55 pm  Full Moon, Harvest Moon 
    20  Mo  10:03 pm  Mercury-Spica: 1.4° S
    22  We   3:21 pm  Autumnal Equinox
    26  Su   3:33 am  Moon Ascending Node
    26  Su   5:44 pm  Moon Apogee: 404600 km
    28  Tu   9:57 pm  Last Quarter
    29  We   4:26 am  Moon North Dec.: 26.1° N
Oct  1  Fr            Venus: 44.9° E

All event times are given for UTC-4 hr: Eastern Daylight Saving Time.

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

If you go to the above site, you can print out a list like the above for the entire year or calendar pages for your time zone.

Sun and Moon Rising and Setting Events

LU                  Ephemeris of Sky Events for Interlochen/TC
September, 2021    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Wed  1| 07:05a  08:18p  13:13 | 09:25p  05:59a |      Rise 01:57a   25%|
|Thu  2| 07:06a  08:17p  13:10 | 09:23p  06:00a |      Rise 02:55a   17%|
|Fri  3| 07:07a  08:15p  13:07 | 09:21p  06:01a |      Rise 04:01a   10%|
|Sat  4| 07:09a  08:13p  13:04 | 09:18p  06:03a |      Rise 05:11a    5%|
+------+-----------------------+----------------+-----------------------+
|Sun  5| 07:10a  08:11p  13:01 | 09:16p  06:04a |      Rise 06:24a    1%|
|Mon  6| 07:11a  08:09p  12:58 | 09:14p  06:06a |New   Set  08:30p    0%|
|Tue  7| 07:12a  08:07p  12:55 | 09:12p  06:07a |      Set  08:53p    1%|
|Wed  8| 07:13a  08:06p  12:52 | 09:10p  06:08a |      Set  09:16p    5%|
|Thu  9| 07:14a  08:04p  12:49 | 09:08p  06:10a |      Set  09:40p   11%|
|Fri 10| 07:16a  08:02p  12:46 | 09:06p  06:11a |      Set  10:05p   19%|
|Sat 11| 07:17a  08:00p  12:43 | 09:04p  06:12a |      Set  10:35p   29%|
+------+-----------------------+----------------+-----------------------+
|Sun 12| 07:18a  07:58p  12:40 | 09:02p  06:13a |      Set  11:12p   40%|
|Mon 13| 07:19a  07:56p  12:37 | 09:00p  06:15a |F Qtr Set  11:57p   52%|
|Tue 14| 07:20a  07:54p  12:33 | 08:58p  06:16a |      Set  12:53a   63%|
|Wed 15| 07:21a  07:52p  12:30 | 08:56p  06:17a |      Set  01:59a   73%|
|Thu 16| 07:23a  07:51p  12:27 | 08:54p  06:19a |      Set  03:10a   82%|
|Fri 17| 07:24a  07:49p  12:24 | 08:52p  06:20a |      Set  04:24a   90%|
|Sat 18| 07:25a  07:47p  12:21 | 08:50p  06:21a |      Set  05:37a   95%|
+------+-----------------------+----------------+-----------------------+
|Sun 19| 07:26a  07:45p  12:18 | 08:48p  06:23a |      Set  06:47a   99%|
|Mon 20| 07:27a  07:43p  12:15 | 08:46p  06:24a |Full  Rise 08:03p  100%|
|Tue 21| 07:29a  07:41p  12:12 | 08:44p  06:25a |      Rise 08:23p   99%|
|Wed 22| 07:30a  07:39p  12:09 | 08:42p  06:26a |      Rise 08:43p   96%|
|Thu 23| 07:31a  07:37p  12:06 | 08:40p  06:28a |      Rise 09:03p   91%|
|Fri 24| 07:32a  07:35p  12:03 | 08:39p  06:29a |      Rise 09:26p   85%|
|Sat 25| 07:33a  07:33p  12:00 | 08:37p  06:30a |      Rise 09:52p   78%|
+------+-----------------------+----------------+-----------------------+
|Sun 26| 07:35a  07:32p  11:57 | 08:35p  06:31a |      Rise 10:23p   69%|
|Mon 27| 07:36a  07:30p  11:53 | 08:33p  06:33a |      Rise 11:00p   60%|
|Tue 28| 07:37a  07:28p  11:50 | 08:31p  06:34a |L Qtr Rise 11:46p   51%|
|Wed 29| 07:38a  07:26p  11:47 | 08:29p  06:35a |      Rise 12:40a   41%|
|Thu 30| 07:39a  07:24p  11:44 | 08:27p  06:36a |      Rise 01:42a   32%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

07/30/2021 – Ephemeris – Previewing August skies

This is Bob Moler with Ephemeris for Friday, July 30th. Today the Sun will be up for 14 hours and 43 minutes, setting at 9:10, and it will rise tomorrow at 6:28. The Moon, 1 day before last quarter, will rise at 12:38 tomorrow morning.

Let’s look ahead at the month of August in the skies. Daylight hours will decrease from 14 hours and 38 minutes on the 1st to 13 hours 16 minutes on the 31st. The altitude of the Sun at local noon, that is, degrees of angle above the horizon, will decrease from 63 degrees Sunday to just over 53 degrees on the 31st. Straits area listeners can subtract one more degree from those angles, but their daylight hours will be a few minutes longer. Local noon, when the Sun is due south, is about 1:43 p.m. The Perseid meteor shower will reach its peak at between 3 and 6 p.m. on the 12th. That means that more than likely the early mornings of the 12th and 13th will be equally good for viewing them. I tend to prefer viewing before the peak, if given a choice.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.

Addendum

August Evening Star Chart

Star Chart for August 2020 (10 pm EDT, August 15, 2021). Click on image to enlarge it. Created using my LookingUp program.

The planets and stars are plotted for the 15th at 10 p.m. EDT in the evening and 5 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.

Note the chart times are for the 15th. For each week before the 15th, add ½ hour (28 minutes if you’re picky). For each week after the 15th, subtract ½ hour. The planet positions are updated each Wednesday on this blog. For planet positions on dates other than the 15th.

August Morning Star Chart

Star Chart for August mornings, (5 a.m. EDT, August 15, 2021). Click on image to enlarge. Created using my LookingUp program.

For a list of constellation names to go with the abbreviations click here.

• Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
• Leaky dipper drips on Leo.
• Follow the arc of the handle of the Big Dipper to the star Arcturus, and
• Extend like a spike to Spica.
• The Summer Triangle is in red.
• PerR is the radiant of the Perseid meteor shower (Peaks on the 12th)

Twilight Limits, Nautical and Astronomical

			EDT
	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2021-08-01	4h31m	5h19m	22h26m	23h15m	23h15m	1h00m	0.35
2021-08-02	4h32m	5h20m	22h25m	23h13m	23h13m	1h25m	0.26
2021-08-03	4h34m	5h22m	22h23m	23h11m	23h11m	1h55m	0.18
2021-08-04	4h36m	5h23m	22h21m	23h08m	23h08m	2h31m	0.11
2021-08-05	4h38m	5h25m	22h20m	23h06m	23h06m	3h16m	0.06
2021-08-06	4h40m	5h26m	22h18m	23h04m	23h04m	4h09m	0.02
2021-08-07	4h42m	5h28m	22h16m	23h02m	23h02m	4h42m	0
2021-08-08	4h44m	5h29m	22h14m	23h00m	23h00m	4h44m	0
2021-08-09	4h46m	5h31m	22h13m	22h58m	22h58m	4h46m	0.03
2021-08-10	4h48m	5h32m	22h11m	22h55m	22h55m	4h48m	0.08
2021-08-11	4h50m	5h34m	22h09m	22h53m	22h53m	4h50m	0.15
2021-08-12	4h51m	5h35m	22h07m	22h51m	23h13m	4h51m	0.24
2021-08-13	4h53m	5h37m	22h05m	22h49m	23h36m	4h53m	0.34
2021-08-14	4h55m	5h38m	22h03m	22h47m	–	4h55m	0.45
2021-08-15	4h57m	5h40m	22h02m	22h44m	0h03m	4h57m	0.57
2021-08-16	4h59m	5h41m	22h00m	22h42m	0h34m	4h59m	0.68
2021-08-17	5h01m	5h43m	21h58m	22h40m	1h13m	5h01m	0.78
2021-08-18	5h02m	5h44m	21h56m	22h38m	2h02m	5h02m	0.87
2021-08-19	5h04m	5h46m	21h54m	22h36m	3h02m	5h04m	0.94
2021-08-20	5h06m	5h47m	21h52m	22h33m	4h12m	5h06m	0.98
2021-08-21	5h08m	5h49m	21h50m	22h31m	–	–	1
2021-08-22	5h09m	5h50m	21h48m	22h29m	–	–	0.99
2021-08-23	5h11m	5h52m	21h46m	22h27m	–	–	0.97
2021-08-24	5h13m	5h53m	21h44m	22h24m	–	–	0.92
2021-08-25	5h15m	5h54m	21h42m	22h22m	–	–	0.86
2021-08-26	5h16m	5h56m	21h40m	22h20m	22h20m	22h40m	0.78
2021-08-27	5h18m	5h57m	21h38m	22h18m	22h18m	23h01m	0.69
2021-08-28	5h20m	5h59m	21h36m	22h15m	22h15m	23h25m	0.6
2021-08-29	5h21m	6h00m	21h34m	22h13m	22h13m	23h53m	0.51
2021-08-30	5h23m	6h01m	21h32m	22h11m	22h11m	–	0.42
2021-08-31	5h24m	6h03m	21h30m	22h09m	22h09m	0h26m	0.32

Twilight calendar was generated using Cartes du Ciel (Sky Charts).

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

    Date     Time    Event
Aug  1  Su            Venus: 33.1° E
     1  Su  10:00 am  Mercury Superior Conj.
     2  Mo   1:24 am  Saturn Opposition
     2  Mo   3:35 am  Moon Apogee: 404400 km
     2  Mo  10:51 pm  Moon Ascending Node
     5  Th  12:46 pm  Moon North Dec.: 25.7° N
     8  Su   9:50 am  New Moon
    11  We   3:00 am  Moon-Venus: 4.4° S
    12  Th   3:11 pm  Perseid Shower: ZHR = 90
    15  Su  11:20 am  First Quarter
    16  Mo  12:04 pm  Moon Descending Node
    17  Tu   5:23 am  Moon Perigee: 369100 km
    18  We   6:24 pm  Moon South Dec.: 25.8° S
    18  We  11:03 pm  Mercury-Mars: 0.1° N
    19  Th   7:05 pm  Jupiter Opposition
    20  Fr   6:19 pm  Moon-Saturn: 3.8° N
    22  Su  12:52 am  Moon-Jupiter: 4.1° N
    22  Su   8:02 am  Full Moon
    29  Su  10:22 pm  Moon Apogee: 404100 km
    30  Mo   1:13 am  Moon Ascending Node
    30  Mo   3:13 am  Last Quarter
Sep  1  We            Venus: 39.9° E

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

If you go to the above site you can print out a list like the above for the entire year or calendar pages for your time zone.

Sun and Moon Rising and Setting Events

                  Ephemeris of Sky Events for Interlochen/TC
August, 2021    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Sun  1| 06:29a  09:08p  14:38 | 10:23p  05:13a |      Rise 01:25a   36%|
|Mon  2| 06:30a  09:06p  14:36 | 10:21p  05:15a |      Rise 01:55a   28%|
|Tue  3| 06:31a  09:05p  14:33 | 10:20p  05:16a |      Rise 02:31a   20%|
|Wed  4| 06:32a  09:04p  14:31 | 10:18p  05:18a |      Rise 03:16a   13%|
|Thu  5| 06:33a  09:02p  14:29 | 10:16p  05:19a |      Rise 04:09a    7%|
|Fri  6| 06:35a  09:01p  14:26 | 10:14p  05:21a |      Rise 05:11a    3%|
|Sat  7| 06:36a  09:00p  14:23 | 10:13p  05:22a |      Rise 06:18a    1%|
+------+-----------------------+----------------+-----------------------+
|Sun  8| 06:37a  08:58p  14:21 | 10:11p  05:24a |New   Set  09:35p    0%|
|Mon  9| 06:38a  08:57p  14:18 | 10:09p  05:25a |      Set  10:03p    2%|
|Tue 10| 06:39a  08:55p  14:16 | 10:07p  05:27a |      Set  10:27p    7%|
|Wed 11| 06:40a  08:54p  14:13 | 10:05p  05:28a |      Set  10:50p   13%|
|Thu 12| 06:42a  08:52p  14:10 | 10:04p  05:30a |      Set  11:13p   22%|
|Fri 13| 06:43a  08:51p  14:08 | 10:02p  05:31a |      Set  11:36p   32%|
|Sat 14| 06:44a  08:49p  14:05 | 10:00p  05:33a |      Set  12:03a   43%|
+------+-----------------------+----------------+-----------------------+
|Sun 15| 06:45a  08:48p  14:02 | 09:58p  05:34a |F Qtr Set  12:34a   54%|
|Mon 16| 06:46a  08:46p  13:59 | 09:56p  05:36a |      Set  01:13a   65%|
|Tue 17| 06:47a  08:44p  13:56 | 09:54p  05:37a |      Set  02:02a   76%|
|Wed 18| 06:49a  08:43p  13:54 | 09:52p  05:39a |      Set  03:02a   85%|
|Thu 19| 06:50a  08:41p  13:51 | 09:50p  05:40a |      Set  04:11a   92%|
|Fri 20| 06:51a  08:39p  13:48 | 09:48p  05:42a |      Set  05:26a   97%|
|Sat 21| 06:52a  08:38p  13:45 | 09:46p  05:43a |      Set  06:40a  100%|
+------+-----------------------+----------------+-----------------------+
|Sun 22| 06:53a  08:36p  13:42 | 09:45p  05:44a |Full  Rise 09:15p  100%|
|Mon 23| 06:54a  08:34p  13:39 | 09:43p  05:46a |      Rise 09:39p   97%|
|Tue 24| 06:56a  08:33p  13:36 | 09:41p  05:47a |      Rise 10:00p   93%|
|Wed 25| 06:57a  08:31p  13:34 | 09:39p  05:49a |      Rise 10:20p   87%|
|Thu 26| 06:58a  08:29p  13:31 | 09:37p  05:50a |      Rise 10:40p   79%|
|Fri 27| 06:59a  08:27p  13:28 | 09:35p  05:52a |      Rise 11:01p   71%|
|Sat 28| 07:00a  08:26p  13:25 | 09:33p  05:53a |      Rise 11:25p   62%|
+------+-----------------------+----------------+-----------------------+
|Sun 29| 07:02a  08:24p  13:22 | 09:31p  05:54a |      Rise 11:53p   53%|
|Mon 30| 07:03a  08:22p  13:19 | 09:29p  05:56a |L Qtr Rise 12:26a   43%|
|Tue 31| 07:04a  08:20p  13:16 | 09:27p  05:57a |      Rise 01:07a   34%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

07/01/2021 – Ephemeris – Looking ahead at July’s skies

This is Ephemeris for Thursday, July 1st. Today the Sun will be up for 15 hours and 30 minutes, setting at 9:32, and it will rise tomorrow at 6:01. The Moon, at last quarter today, will rise at 1:54 tomorrow morning.

Let’s preview July’s skies. The Sun, having reached its northern solstice, is beginning to slide southward again, at first imperceptibly, then with greater speed. The daylight hours will decrease from 15 hours and 30 minutes today to 14 hours 41 minutes at month’s end. The daylight hours will be slightly shorter south of Interlochen, and slightly longer to the north. The altitude of the Sun at local noon, when it is due south, will decrease from 68 degrees today to 63 degrees at month’s end. The Sun will be a degree lower in the Straits area. Despite the warmth, the Earth will reach its greatest distance from the Sun late Monday. That’s called aphelion where the Sun will be almost 94.5 million miles (152 million kilometers) away, which makes summer the longest season.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT-4). They may be different for your location.

Addendum

July Evening Star Chart

Star Chart for July 2021 (11 p.m. EDT, July 15, 2021). Created using my LookingUp program. Click on image to enlarge.

The planets and stars are plotted for the 15th at 11 p.m. EDT in the evening and 4:30 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.

Note the chart times are for the 15th. For each week before the 15th, add ½ hour (28 minutes if you’re picky). For each week after the 15th, subtract ½ hour. The planet positions are updated each Wednesday on this blog. For planet positions on dates other than the 15th.

July Morning Star Chart

Star Chart for July mornings, 2021 (4:30 a.m. EDT July 15, 2021). Created using my LookingUp program. Click on image to enlarge.

For a list of constellation names to go with the abbreviations, click here.

• Pointer stars at the front of the bowl of the Big Dipper point to Polaris, the North Star.
• Leaky dipper drips on Leo.
• Follow the arc of the handle of the Big Dipper to the star Arcturus, and
• Extend like a spike to Spica.
• The Summer Triangle is in red.
• DAqR is the radiant of the South Delta Aquariid meteor shower (Peaks on the 27th)

Twilight Limits, Nautical and Astronomical

			EDT
	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2021-07-01	3h38m	4h41m	23h00m	0h03m	0h03m	1h35m	0.47
2021-07-02	3h39m	4h42m	22h59m	0h02m	0h02m	1h55m	0.37
2021-07-03	3h40m	4h42m	22h59m	0h01m	0h01m	2h14m	0.28
2021-07-04	3h41m	4h43m	22h58m	0h00m	0h00m	2h35m	0.2
2021-07-05	3h43m	4h44m	22h58m	23h59m	23h59m	2h57m	0.13
2021-07-06	3h44m	4h45m	22h57m	23h58m	23h58m	3h24m	0.07
2021-07-07	3h45m	4h46m	22h57m	23h57m	23h57m	3h45m	0.03
2021-07-08	3h47m	4h47m	22h56m	23h56m	23h56m	3h47m	0.01
2021-07-09	3h48m	4h48m	22h55m	23h55m	23h55m	3h48m	0
2021-07-10	3h50m	4h49m	22h54m	23h53m	23h53m	3h50m	0.01
2021-07-11	3h52m	4h50m	22h54m	23h52m	23h52m	3h52m	0.05
2021-07-12	3h53m	4h51m	22h53m	23h51m	23h51m	3h53m	0.1
2021-07-13	3h55m	4h53m	22h52m	23h49m	0h00m	3h55m	0.17
2021-07-14	3h57m	4h54m	22h51m	23h48m	–	3h57m	0.26
2021-07-15	3h58m	4h55m	22h50m	23h46m	0h23m	3h58m	0.37
2021-07-16	4h00m	4h56m	22h49m	23h45m	0h46m	4h00m	0.48
2021-07-17	4h02m	4h58m	22h47m	23h43m	1h08m	4h02m	0.59
2021-07-18	4h04m	4h59m	22h46m	23h41m	1h33m	4h04m	0.7
2021-07-19	4h06m	5h00m	22h45m	23h40m	2h01m	4h06m	0.8
2021-07-20	4h07m	5h02m	22h44m	23h38m	2h35m	4h07m	0.89
2021-07-21	4h09m	5h03m	22h43m	23h36m	3h18m	4h09m	0.95
2021-07-22	4h11m	5h04m	22h41m	23h34m	–	–	0.99
2021-07-23	4h13m	5h06m	22h40m	23h32m	–	–	1
2021-07-24	4h15m	5h07m	22h39m	23h31m	–	–	0.98
2021-07-25	4h17m	5h09m	22h37m	23h29m	–	–	0.94
2021-07-26	4h19m	5h10m	22h36m	23h27m	–	–	0.88
2021-07-27	4h21m	5h11m	22h34m	23h25m	23h25m	23h37m	0.81
2021-07-28	4h23m	5h13m	22h33m	23h23m	23h23m	23h58m	0.72
2021-07-29	4h25m	5h14m	22h31m	23h21m	23h21m	–	0.63
2021-07-30	4h27m	5h16m	22h30m	23h19m	23h19m	0h17m	0.53
2021-07-31	4h29m	5h17m	22h28m	23h17m	23h17m	0h38m	0.44

Twilight calendar was generated using Cartes du Ciel (Sky Charts).

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

Date         Time     Event
Jul  1  Th            Venus: 25.4° E
     1  Th   5:11 pm  Last Quarter
     2  Fr  10:45 pm  Venus-Beehive: 0.1° N
     4  Su   3:59 pm  Mercury Elongation: 21.6° W
     5  Mo  10:48 am  Moon Apogee: 405300 km
     5  Mo  10:59 pm  Aphelion: 1.0167 AU
     6  Tu   6:41 pm  Moon Ascending Node
     8  Th  12:38 am  Moon-Mercury: 4.1° S
     9  Fr   6:05 am  Moon North Dec.: 25.6° N
     9  Fr   9:16 pm  New Moon
    12  Mo   5:10 am  Moon-Venus: 3.5° S
    12  Mo   6:10 am  Moon-Mars: 4° S
    13  Tu   9:17 am  Venus-Mars: 0.5° N
    17  Sa   6:11 am  First Quarter
    20  Tu   9:22 am  Moon Descending Node
    21  We   6:30 am  Moon Perigee: 364500 km
    21  We   5:21 pm  Venus-Regulus: 1.1° N
    22  Th  11:12 am  Moon South Dec.: 25.6° S
    23  Fr  10:37 pm  Full Moon
    24  Sa  12:42 pm  Moon-Saturn: 3.9° N
    25  Su   9:17 pm  Moon-Jupiter: 4.3° N
    27  Tu  11:17 pm  Delta Aquariid Shower: ZHR = 20
    29  Th  10:09 am  Mars-Regulus: 0.6° N
    31  Sa   9:16 am  Last Quarter
Aug  1  Su            Venus: 33.1° E

All event times are given for UTC-4 hr: Eastern Daylight Saving Time.

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

If you go to the above site you can print out a list like the above for the entire year or calendar pages for your time zone.

Sun and Moon Rising and Setting Events

LU                  Ephemeris of Sky Events for Interlochen/TC
July, 2021    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Thu  1| 06:01a  09:32p  15:30 | 10:57p  04:35a |L Qtr Rise 01:54a   49%|
|Fri  2| 06:01a  09:31p  15:29 | 10:56p  04:36a |      Rise 02:14a   39%|
|Sat  3| 06:02a  09:31p  15:29 | 10:56p  04:37a |      Rise 02:34a   30%|
+------+-----------------------+----------------+-----------------------+
|Sun  4| 06:03a  09:31p  15:28 | 10:55p  04:38a |      Rise 02:57a   22%|
|Mon  5| 06:03a  09:30p  15:27 | 10:55p  04:39a |      Rise 03:24a   15%|
|Tue  6| 06:04a  09:30p  15:26 | 10:54p  04:40a |      Rise 03:56a    9%|
|Wed  7| 06:05a  09:30p  15:24 | 10:53p  04:40a |      Rise 04:36a    4%|
|Thu  8| 06:05a  09:29p  15:23 | 10:53p  04:42a |      Rise 05:23a    1%|
|Fri  9| 06:06a  09:29p  15:22 | 10:52p  04:43a |New   Set  09:42p    0%|
|Sat 10| 06:07a  09:28p  15:21 | 10:51p  04:44a |      Set  10:26p    1%|
+------+-----------------------+----------------+-----------------------+
|Sun 11| 06:08a  09:28p  15:19 | 10:50p  04:45a |      Set  11:02p    4%|
|Mon 12| 06:09a  09:27p  15:18 | 10:49p  04:46a |      Set  11:33p    9%|
|Tue 13| 06:09a  09:26p  15:16 | 10:48p  04:47a |      Set  11:59p   16%|
|Wed 14| 06:10a  09:26p  15:15 | 10:47p  04:48a |      Set  12:23a   24%|
|Thu 15| 06:11a  09:25p  15:13 | 10:46p  04:49a |      Set  12:45a   34%|
|Fri 16| 06:12a  09:24p  15:11 | 10:45p  04:51a |      Set  01:08a   45%|
|Sat 17| 06:13a  09:23p  15:10 | 10:44p  04:52a |F Qtr Set  01:32a   57%|
+------+-----------------------+----------------+-----------------------+
|Sun 18| 06:14a  09:23p  15:08 | 10:43p  04:53a |      Set  02:00a   68%|
|Mon 19| 06:15a  09:22p  15:06 | 10:42p  04:55a |      Set  02:35a   78%|
|Tue 20| 06:16a  09:21p  15:04 | 10:40p  04:56a |      Set  03:18a   87%|
|Wed 21| 06:17a  09:20p  15:02 | 10:39p  04:57a |      Set  04:13a   94%|
|Thu 22| 06:18a  09:19p  15:00 | 10:38p  04:59a |      Set  05:18a   98%|
|Fri 23| 06:19a  09:18p  14:58 | 10:37p  05:00a |Full  Rise 09:35p  100%|
|Sat 24| 06:20a  09:17p  14:56 | 10:35p  05:02a |      Rise 10:16p   99%|
+------+-----------------------+----------------+-----------------------+
|Sun 25| 06:21a  09:16p  14:54 | 10:34p  05:03a |      Rise 10:49p   95%|
|Mon 26| 06:22a  09:15p  14:52 | 10:32p  05:04a |      Rise 11:15p   90%|
|Tue 27| 06:23a  09:14p  14:50 | 10:31p  05:06a |      Rise 11:37p   82%|
|Wed 28| 06:24a  09:13p  14:48 | 10:29p  05:07a |      Rise 11:58p   74%|
|Thu 29| 06:25a  09:11p  14:45 | 10:28p  05:09a |      Rise 12:17a   65%|
|Fri 30| 06:27a  09:10p  14:43 | 10:26p  05:10a |      Rise 12:38a   55%|
|Sat 31| 06:28a  09:09p  14:41 | 10:25p  05:12a |L Qtr Rise 01:00a   46%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

06/01/2021 – Ephemeris – Previewing June Skies

This is Ephemeris for Tuesday, June 1st. Today the Sun will be up for 15 hours and 21 minutes, setting at 9:21, and it will rise tomorrow at 5:59. The Moon, 1 day before last quarter, will rise at 2:49 tomorrow morning.

This is the 46th anniversary of this program as we start our 47th orbit of the Sun. Let’s take a look at June skies. There will be a lot of Sunshine this month. The daylight hours will increase a bit from 15 hours and 21 minutes today to 15 hours and 34 minutes on the 21st, retreating back to 15 hours 31 minutes at month’s end. At this time of the year the sunset times for Ludington, Interlochen, Petoskey and Mackinaw City are very nearly the same. However, the sunrise times are at their most divergent. With Ludington’s sunrise being 14 minutes later than Mackinaw City’s. The altitude of the Sun above the southern horizon at local noon (1:44 pm in Interlochen) on the solstice, June 20th will be 68 and three-quarters degrees in Interlochen. Summer will start at 11:32 pm that night.

The big event this month will be a sunrise partial eclipse on the 10th. I’ll have more information next week.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

June Evening Star Chart

Star Chart for June 2021 (11 p.m. EDT June 15, 2021). Created using my LookingUp program. Click on image to enlarge.

The planets and stars are plotted for the 15th at 11 p.m. EDT in the evening and 4 a.m. for the morning chart. These are the chart times. Note that Interlochen/Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.
Note the chart times of 11 p.m. and 5 a.m. are for the 15th. For each week before the 15th, add ½ hour (28 minutes if you’re picky). For each week after the 15th, subtract ½ hour, or 28 minutes. The planet positions are updated each Wednesday on this blog. For planet positions on dates other than the 15th, check the Wednesday planet posts on this blog for weekly positions.

June Morning Star Chart

Star Chart for June mornings 2021 (4 am EDT June 15, 2021). Created using my LookingUp program. Click on image to enlarge.

For a list of constellation names to go with the abbreviations, click here.

• Pointer stars at the front of the bowl of the Big Dipper point to Polaris, the North Star.
• Leaky dipper drips on Leo
• Follow the arc of the handle of the Big Dipper to the star Arcturus, and
• Extend like a spike to Spica,

Twilight Limits, Nautical and Astronomical

			EDT
	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2021-06-01	3h42m	4h42m	22h47m	23h46m	23h46m	2h23m	0.51
2021-06-02	3h41m	4h41m	22h48m	23h48m	23h48m	2h49m	0.41
2021-06-03	3h40m	4h40m	22h49m	23h49m	23h49m	3h11m	0.32
2021-06-04	3h39m	4h39m	22h50m	23h51m	23h51m	3h30m	0.23
2021-06-05	3h38m	4h39m	22h51m	23h52m	23h52m	3h38m	0.16
2021-06-06	3h37m	4h38m	22h52m	23h54m	23h54m	3h37m	0.09
2021-06-07	3h36m	4h38m	22h53m	23h55m	23h55m	3h36m	0.05
2021-06-08	3h35m	4h37m	22h54m	23h56m	23h56m	3h35m	0.01
2021-06-09	3h34m	4h37m	22h55m	23h57m	23h57m	3h34m	0
2021-06-10	3h33m	4h36m	22h55m	23h58m	23h58m	3h33m	0.01
2021-06-11	3h33m	4h36m	22h56m	23h59m	23h59m	3h33m	0.03
2021-06-12	3h32m	4h36m	22h57m	0h00m	0h00m	3h32m	0.07
2021-06-13	3h32m	4h35m	22h58m	0h01m	0h01m	3h32m	0.13
2021-06-14	3h31m	4h35m	22h58m	0h02m	0h26m	3h31m	0.21
2021-06-15	3h31m	4h35m	22h59m	0h03m	1h01m	3h31m	0.3
2021-06-16	3h31m	4h35m	22h59m	0h03m	1h30m	3h31m	0.4
2021-06-17	3h31m	4h35m	23h00m	0h04m	1h55m	3h31m	0.5
2021-06-18	3h31m	4h35m	23h00m	0h05m	2h18m	3h31m	0.62
2021-06-19	3h31m	4h35m	23h00m	0h05m	2h41m	3h31m	0.72
2021-06-20	3h31m	4h35m	23h01m	0h05m	3h05m	3h31m	0.82
2021-06-21	3h31m	4h36m	23h01m	0h05m	3h31m	3h31m	0.91
2021-06-22	3h31m	4h36m	23h01m	0h06m	–	–	0.96
2021-06-23	3h32m	4h36m	23h01m	0h06m	–	–	1
2021-06-24	3h32m	4h37m	23h01m	0h06m	–	–	1
2021-06-25	3h33m	4h37m	23h01m	0h05m	–	–	0.97
2021-06-26	3h33m	4h38m	23h01m	0h05m	–	–	0.92
2021-06-27	3h34m	4h38m	23h01m	0h05m	–	–	0.85
2021-06-28	3h35m	4h39m	23h01m	0h04m	0h04m	0h22m	0.76
2021-06-29	3h36m	4h39m	23h00m	0h04m	0h04m	0h50m	0.67
2021-06-30	3h37m	4h40m	23h00m	0h03m	0h03m	1h14m	0.57

The twilight calendar was generated using Cartes du Ciel (Sky Charts), with some corrections.

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

Jun  1  Tu            Venus: 17.5° E
     1  Tu   4:57 am  Moon-Jupiter: 4.9° N
     2  We   3:24 am  Last Quarter
     7  Mo  10:27 pm  Moon Apogee: 406200 km
     9  We  12:42 pm  Moon Ascending Node
    10  Th   6:43 am  Annular Solar Eclipse*
    10  Th   6:53 am  New Moon
    10  Th   9:06 pm  Mercury Inferior Conj.
    12  Sa  12:11 am  Moon North Dec.: 25.6° N
    12  Sa   2:44 am  Moon-Venus: 1.6° S
    13  Su   3:52 pm  Moon-Mars: 3° S
    14  Mo   2:47 am  Moon-Beehive: 3.1° S
    17  Th  11:54 pm  First Quarter
    20  Su  11:32 pm  Summer Solstice
    21  Mo  11:57 am  Venus-Pollux: 5.2° S
    22  Tu   4:54 pm  Mercury-Aldebaran: 6.4° N
    23  We   1:21 am  Mars-Beehive: 0.3° S
    23  We   2:07 am  Moon Descending Node
    23  We   5:58 am  Moon Perigee: 360000 km
    24  Th   2:40 pm  Full Moon
    25  Fr   1:49 am  Moon South Dec.: 25.6° S
    27  Su   5:30 am  Moon-Saturn: 4.1° N
    28  Mo   2:38 pm  Moon-Jupiter: 4.6° N

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

Sun and Moon Rising and Setting Events

LU                  Ephemeris of Sky Events for Interlochen/TC
June, 2021    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Tue  1| 06:00a  09:21p  15:21 | 10:45p  04:37a |      Rise 02:49a   53%|
|Wed  2| 05:59a  09:22p  15:22 | 10:46p  04:36a |L Qtr Rise 03:10a   43%|
|Thu  3| 05:59a  09:23p  15:23 | 10:47p  04:35a |      Rise 03:30a   33%|
|Fri  4| 05:58a  09:23p  15:25 | 10:48p  04:34a |      Rise 03:49a   25%|
|Sat  5| 05:58a  09:24p  15:26 | 10:49p  04:34a |      Rise 04:09a   17%|
+------+-----------------------+----------------+-----------------------+
|Sun  6| 05:58a  09:25p  15:27 | 10:50p  04:33a |      Rise 04:30a   10%|
|Mon  7| 05:57a  09:26p  15:28 | 10:50p  04:33a |      Rise 04:54a    5%|
|Tue  8| 05:57a  09:26p  15:29 | 10:51p  04:32a |      Rise 05:22a    2%|
|Wed  9| 05:57a  09:27p  15:30 | 10:52p  04:32a |      Rise 05:57a    0%|
|Thu 10| 05:57a  09:27p  15:30 | 10:53p  04:31a |New   Set  10:01p    0%|
|Fri 11| 05:56a  09:28p  15:31 | 10:54p  04:31a |      Set  10:56p    2%|
|Sat 12| 05:56a  09:28p  15:32 | 10:54p  04:31a |      Set  11:45p    6%|
+------+-----------------------+----------------+-----------------------+
|Sun 13| 05:56a  09:29p  15:32 | 10:55p  04:30a |      Set  12:26a   12%|
|Mon 14| 05:56a  09:29p  15:33 | 10:55p  04:30a |      Set  01:00a   19%|
|Tue 15| 05:56a  09:30p  15:33 | 10:56p  04:30a |      Set  01:29a   28%|
|Wed 16| 05:56a  09:30p  15:34 | 10:56p  04:30a |      Set  01:55a   37%|
|Thu 17| 05:56a  09:31p  15:34 | 10:57p  04:30a |F Qtr Set  02:18a   48%|
|Fri 18| 05:56a  09:31p  15:34 | 10:57p  04:30a |      Set  02:41a   59%|
|Sat 19| 05:56a  09:31p  15:34 | 10:58p  04:30a |      Set  03:04a   70%|
+------+-----------------------+----------------+-----------------------+
|Sun 20| 05:57a  09:31p  15:34 | 10:58p  04:30a |      Set  03:31a   80%|
|Mon 21| 05:57a  09:32p  15:34 | 10:58p  04:30a |      Set  04:02a   89%|
|Tue 22| 05:57a  09:32p  15:34 | 10:58p  04:31a |      Set  04:41a   95%|
|Wed 23| 05:57a  09:32p  15:34 | 10:58p  04:31a |      Set  05:30a   99%|
|Thu 24| 05:58a  09:32p  15:34 | 10:58p  04:31a |Full  Rise 09:59p  100%|
|Fri 25| 05:58a  09:32p  15:34 | 10:58p  04:32a |      Rise 10:58p   98%|
|Sat 26| 05:58a  09:32p  15:33 | 10:58p  04:32a |      Rise 11:45p   93%|
+------+-----------------------+----------------+-----------------------+
|Sun 27| 05:59a  09:32p  15:33 | 10:58p  04:33a |      Rise 12:22a   86%|
|Mon 28| 05:59a  09:32p  15:32 | 10:58p  04:33a |      Rise 12:50a   78%|
|Tue 29| 06:00a  09:32p  15:32 | 10:57p  04:34a |      Rise 01:14a   69%|
|Wed 30| 06:00a  09:32p  15:31 | 10:57p  04:35a |      Rise 01:35a   59%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

04/30/2021 – Ephemeris – Previewing March skies

This is Bob Moler with Ephemeris for Arbor Day, Friday, April 30th. Today the Sun will be up for 14 hours and 13 minutes, setting at 8:46, and it will rise tomorrow at 6:32. The Moon, 3 days before last quarter, will rise at 1:34 tomorrow morning.

The month of May starts tomorrow, when spring really gets going. Daylight hours in the Interlochen/Traverse City area will increase from 14 hours and 15 minutes tomorrow to 15 hours 19 minutes on the 31st. The altitude, or angle, of the Sun above the southern horizon at local noon will ascend from 61 degrees now to 67 degrees at month’s end. The altitude of the Sun in the Straits area will be a degree lower than that, but your daylight hours will be a few minutes longer. Local apparent noon this month, when the Sun passes due south, will be about 1:38 p.m. This is the month of the Eta Aquariid meteor shower which will reach its peak next week Thursday morning. There will be about a 2-hour viewing period starting at 3:15 am. We will get a chance to see the beginning of a lunar eclipse near sunrise on Wednesday the 26th.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

May Evening Star Chart

Star Chart for May 2021 (11 p.m. EDT May 15, 2021). Created using my LookingUp program. Click on image to enlarge.

The planets and stars are plotted for the 15th at 11 p.m. EDT in the evening and 5 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.
Note the chart times of 11 p.m. and 5 a.m. are for the 15th. For each week before the 15th add ½ hour (28 minutes if you’re picky). For each week after the 15th subtract ½ hour, or 28 minutes. The planet positions are updated each Wednesday on this blog. For planet positions on dates other than the 15th, check the Wednesday planet posts on this blog for weekly positions.

May Morning Star Chart

Star Chart for May mornings 2021 (5 a.m. EDT May 15, 2020). Created using my LookingUp program. Click on image to enlarge.

For a list of constellation names to go with the abbreviations click here.

• Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
• Leaky dipper drips on Leo
• Follow the arc of the handle of the Big Dipper to the star Arcturus, and
• Extend like a spike to Spica,
• EaqR is the radiant of the Aquariid meteor shower that peaks on the 5th.  Best viewing is before the peak this year due to the bright Moon.

Twilight Limits, Nautical and Astronomical

			EDT
	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2021-05-01	4h40m	5h24m	22h02m	22h47m	22h47m	1h35m	0.67
2021-05-02	4h38m	5h23m	22h04m	22h49m	22h49m	2h32m	0.57
2021-05-03	4h36m	5h21m	22h05m	22h51m	22h51m	3h17m	0.46
2021-05-04	4h33m	5h19m	22h07m	22h53m	22h53m	3h52m	0.36
2021-05-05	4h31m	5h17m	22h09m	22h55m	22h55m	4h20m	0.27
2021-05-06	4h29m	5h16m	22h10m	22h57m	22h57m	4h29m	0.18
2021-05-07	4h27m	5h14m	22h12m	22h59m	22h59m	4h27m	0.11
2021-05-08	4h25m	5h12m	22h13m	23h01m	23h01m	4h25m	0.06
2021-05-09	4h23m	5h11m	22h15m	23h03m	23h03m	4h23m	0.02
2021-05-10	4h21m	5h09m	22h16m	23h05m	23h05m	4h21m	0
2021-05-11	4h19m	5h07m	22h18m	23h07m	23h07m	4h19m	0
2021-05-12	4h17m	5h06m	22h19m	23h09m	23h09m	4h17m	0.02
2021-05-13	4h15m	5h04m	22h21m	23h11m	23h11m	4h15m	0.05
2021-05-14	4h13m	5h03m	22h23m	23h13m	–	4h13m	0.1
2021-05-15	4h11m	5h01m	22h24m	23h15m	0h07m	4h11m	0.17
2021-05-16	4h09m	5h00m	22h26m	23h17m	1h00m	4h09m	0.25
2021-05-17	4h07m	4h58m	22h27m	23h19m	1h46m	4h07m	0.34
2021-05-18	4h05m	4h57m	22h28m	23h21m	2h25m	4h05m	0.44
2021-05-19	4h03m	4h56m	22h30m	23h23m	2h58m	4h03m	0.54
2021-05-20	4h01m	4h54m	22h31m	23h24m	3h26m	4h01m	0.65
2021-05-21	4h00m	4h53m	22h33m	23h26m	3h51m	4h00m	0.76
2021-05-22	3h58m	4h52m	22h34m	23h28m	–	–	0.85
2021-05-23	3h56m	4h51m	22h36m	23h30m	–	–	0.92
2021-05-24	3h54m	4h49m	22h37m	23h32m	–	–	0.98
2021-05-25	3h53m	4h48m	22h38m	23h34m	–	–	1
2021-05-26	3h51m	4h47m	22h40m	23h36m	–	–	0.99
2021-05-27	3h49m	4h46m	22h41m	23h38m	–	–	0.95
2021-05-28	3h48m	4h45m	22h42m	23h39m	23h39m	–	0.89
2021-05-29	3h46m	4h44m	22h43m	23h41m	23h41m	0h19m	0.81
2021-05-30	3h45m	4h43m	22h45m	23h43m	23h43m	1h11m	0.72
2021-05-31	3h44m	4h42m	22h46m	23h44m	23h44m	1h52m	0.61

The twilight calendar was generated using Cartes du Ciel (Sky Charts), with some corrections.

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

May  1  Sa            Venus: 9.4° E
     1  Sa   5:37 am  Moon South Dec.: 25.6° S
     3  Mo   1:02 pm  Moon-Saturn: 4.4° N
     3  Mo   3:50 pm  Last Quarter
     3  Mo  11:01 pm  Mercury-Pleiades: 2.2° S
     4  Tu   5:00 pm  Moon-Jupiter: 4.9° N
     4  Tu   9:30 pm  Eta Aquariid Shower: ZHR = 60
    11  Tu   3:00 pm  New Moon
    11  Tu   5:54 pm  Moon Apogee: 406500 km
    13  Th   6:29 am  Moon Ascending Node
    13  Th   1:59 pm  Moon-Mercury: 2.4° N
    15  Sa   6:25 pm  Moon North Dec.: 25.6° N
    16  Su  12:47 am  Moon-Mars: 1.6° S
    17  Mo   1:59 am  Mercury Elongation: 22° E
    17  Mo   9:08 pm  Moon-Beehive: 3.1° S
    19  We   3:13 pm  First Quarter
    25  Tu   9:52 pm  Moon Perigee: 357300 km
    26  We   7:14 am  Full Moon
    26  We   7:19 am  Total Lunar Eclipse (Start is visible here)
    26  We   3:38 pm  Moon Descending Node
    28  Fr   3:21 pm  Moon South Dec.: 25.6° S
    28  Fr  11:01 pm  Mercury-Venus: 0.4° N
    30  Su   9:22 pm  Moon-Saturn: 4.3° N
    31  Mo   7:39 am  Mars-Pollux: 5.3° S
Jun  1  Tu            Venus: 17.5° E

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

Sun and Moon Rising and Setting Events

LU                  Ephemeris of Sky Events for Interlochen/TC
May, 2021    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Sat  1| 06:32a  08:48p  14:15 | 10:00p  05:20a |      Rise 02:32a   70%|
+------+-----------------------+----------------+-----------------------+
|Sun  2| 06:30a  08:49p  14:18 | 10:02p  05:18a |      Rise 03:17a   59%|
|Mon  3| 06:29a  08:50p  14:21 | 10:03p  05:16a |L Qtr Rise 03:52a   48%|
|Tue  4| 06:28a  08:51p  14:23 | 10:05p  05:14a |      Rise 04:20a   38%|
|Wed  5| 06:26a  08:53p  14:26 | 10:06p  05:13a |      Rise 04:44a   28%|
|Thu  6| 06:25a  08:54p  14:28 | 10:08p  05:11a |      Rise 05:04a   20%|
|Fri  7| 06:24a  08:55p  14:31 | 10:09p  05:09a |      Rise 05:24a   13%|
|Sat  8| 06:22a  08:56p  14:33 | 10:11p  05:08a |      Rise 05:43a    7%|
+------+-----------------------+----------------+-----------------------+
|Sun  9| 06:21a  08:57p  14:36 | 10:13p  05:06a |      Rise 06:03a    3%|
|Mon 10| 06:20a  08:58p  14:38 | 10:14p  05:04a |      Rise 06:25a    1%|
|Tue 11| 06:18a  09:00p  14:41 | 10:16p  05:03a |New   Set  09:03p    0%|
|Wed 12| 06:17a  09:01p  14:43 | 10:17p  05:01a |      Set  10:06p    1%|
|Thu 13| 06:16a  09:02p  14:45 | 10:19p  05:00a |      Set  11:08p    4%|
|Fri 14| 06:15a  09:03p  14:48 | 10:20p  04:58a |      Set  12:07a    9%|
|Sat 15| 06:14a  09:04p  14:50 | 10:22p  04:57a |      Set  01:00a   15%|
+------+-----------------------+----------------+-----------------------+
|Sun 16| 06:13a  09:05p  14:52 | 10:23p  04:55a |      Set  01:46a   23%|
|Mon 17| 06:12a  09:06p  14:54 | 10:25p  04:54a |      Set  02:25a   32%|
|Tue 18| 06:11a  09:08p  14:56 | 10:26p  04:52a |      Set  02:57a   42%|
|Wed 19| 06:10a  09:09p  14:59 | 10:28p  04:51a |F Qtr Set  03:26a   52%|
|Thu 20| 06:09a  09:10p  15:01 | 10:29p  04:50a |      Set  03:51a   63%|
|Fri 21| 06:08a  09:11p  15:03 | 10:30p  04:48a |      Set  04:14a   73%|
|Sat 22| 06:07a  09:12p  15:04 | 10:32p  04:47a |      Set  04:38a   83%|
+------+-----------------------+----------------+-----------------------+
|Sun 23| 06:06a  09:13p  15:06 | 10:33p  04:46a |      Set  05:04a   91%|
|Mon 24| 06:05a  09:14p  15:08 | 10:35p  04:45a |      Set  05:33a   97%|
|Tue 25| 06:04a  09:15p  15:10 | 10:36p  04:44a |      Set  06:09a  100%|
|Wed 26| 06:04a  09:16p  15:12 | 10:37p  04:42a |Full  Rise 09:57p  100%|
|Thu 27| 06:03a  09:17p  15:13 | 10:39p  04:41a |      Rise 11:14p   96%|
|Fri 28| 06:02a  09:18p  15:15 | 10:40p  04:40a |      Rise 12:19a   91%|
|Sat 29| 06:01a  09:19p  15:17 | 10:41p  04:39a |      Rise 01:11a   83%|
+------+-----------------------+----------------+-----------------------+
|Sun 30| 06:01a  09:19p  15:18 | 10:42p  04:38a |      Rise 01:52a   74%|
|Mon 31| 06:00a  09:20p  15:19 | 10:43p  04:38a |      Rise 02:23a   64%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

04/01/2021 – Ephemeris – Previewing April Skies

This is Bob Moler with Ephemeris for Wednesday, March 31st. Today the Sun will be up for 12 hours and 44 minutes, setting at 8:09, and it will rise tomorrow at 7:23. The Moon, 3 days past full, will rise at 12:11 tomorrow morning.

Let’s search for the naked-eye planets for this week. Unfortunately the only one you’ll find in the evening is Mars. It can be found in the west-southwest at 9 pm tonight, above the orange star Aldebaran in the face of Taurus the bull. Mars will set at 1:54 am. Right now three of the other four naked eye planets are just west of the Sun in the Morning sky. Venus is now below and just a bit east of the Sun, setting four minutes after sunset. Only Saturn and Jupiter are at a far enough angle from the Sun to be just spotted in the morning twilight. Saturn will rise at 5:10 am, with Jupiter rising 31 minutes later. By 6:30 am they will be low in the southeast. The Sun is rising earlier by 2 minutes a day now, while sunset is nearly matching that pace in the opposite direction.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

April Evening Star Chart

Star Chart for March 2021 (10 p.m. EDT April 15, 2021). Click on image to enlarge. Created using my LookingUp program. Click on image to enlarge. Created using my LookingUp program.

The planets and stars are plotted for the 15th at 10 p.m. EDT in the evening and 5 a.m. for the morning chart. These are the chart times. The brilliant planet Venus is our Evening Star in the West at chart time. Note that Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour and 45 minutes behind our daylight saving time meridian during EDT).

April Morning Star Chart

Star Chart for April mornings 2021 (5 a.m. EDT April 15, 2021). Click on image to enlarge. Created using my LookingUp program.

For a list of constellation names to go with the abbreviations click here.

• Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
• The leaky bowl of the Big Dipper drips on Leo.
• Follow the arc of the handle of the Big Dipper to the star Arcturus, then
• Follow the spike to Spica.
• The Summer Triangle appears in red.
• LyrR is the radiant of the Lyrid meteor shower which will reach peak on the morning of the 22nd.

• the 22nd.

Twilight Limits, Nautical and Astronomical

	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2021-04-01	5h46m	6h23m	21h18m	21h54m	21h54m	0h11m	0.74
2021-04-02	5h44m	6h21m	21h19m	21h56m	21h56m	1h29m	0.64
2021-04-03	5h42m	6h19m	21h20m	21h57m	21h57m	2h42m	0.52
2021-04-04	5h39m	6h17m	21h22m	21h59m	21h59m	3h44m	0.42
2021-04-05	5h37m	6h15m	21h23m	22h01m	22h01m	4h35m	0.31
2021-04-06	5h35m	6h13m	21h25m	22h02m	22h02m	5h16m	0.22
2021-04-07	5h33m	6h11m	21h26m	22h04m	22h04m	5h33m	0.14
2021-04-08	5h31m	6h09m	21h27m	22h05m	22h05m	5h31m	0.08
2021-04-09	5h28m	6h07m	21h29m	22h07m	22h07m	5h28m	0.03
2021-04-10	5h26m	6h05m	21h30m	22h09m	22h09m	5h26m	0.01
2021-04-11	5h24m	6h03m	21h32m	22h10m	22h10m	5h24m	0
2021-04-12	5h22m	6h01m	21h33m	22h12m	22h12m	5h22m	0.01
2021-04-13	5h20m	5h59m	21h35m	22h14m	22h14m	5h20m	0.04
2021-04-14	5h17m	5h57m	21h36m	22h16m	23h12m	5h17m	0.08
2021-04-15	5h15m	5h55m	21h38m	22h17m	–	5h15m	0.14
2021-04-16	5h13m	5h53m	21h39m	22h19m	0h14m	5h13m	0.22
2021-04-17	5h11m	5h51m	21h41m	22h21m	1h15m	5h11m	0.3
2021-04-18	5h09m	5h49m	21h42m	22h23m	2h12m	5h09m	0.39
2021-04-19	5h06m	5h47m	21h44m	22h24m	3h03m	5h06m	0.49
2021-04-20	5h04m	5h45m	21h45m	22h26m	3h47m	5h04m	0.59
2021-04-21	5h02m	5h43m	21h47m	22h28m	4h25m	5h02m	0.7
2021-04-22	5h00m	5h41m	21h48m	22h30m	4h56m	5h00m	0.79
2021-04-23	4h57m	5h39m	21h50m	22h32m	–	–	0.88
2021-04-24	4h55m	5h37m	21h51m	22h34m	–	–	0.94
2021-04-25	4h53m	5h35m	21h53m	22h35m	–	–	0.99
2021-04-26	4h51m	5h34m	21h55m	22h37m	–	–	1
2021-04-27	4h49m	5h32m	21h56m	22h39m	–	–	0.98
2021-04-28	4h46m	5h30m	21h58m	22h41m	22h41m	23h06m	0.94
2021-04-29	4h44m	5h28m	21h59m	22h43m	22h43m	–	0.87
2021-04-30	4h42m	5h26m	22h01m	22h45m	22h45m	0h25m	0.78

Twilight calendar was generated using Cartes du Ciel (Sky Charts).

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

   Date     Time      Event      
Apr  1  Th            Venus: 2° E
     1  Th  10:41 pm  Moon Descending Node
     3  Sa  10:08 pm  Moon South Dec.: 25.4° S
     4  Su   6:02 am  Last Quarter
     6  Tu   4:34 am  Moon-Saturn: 4.2° N
     7  We   3:15 am  Moon-Jupiter: 4.7° N
    11  Su  10:31 pm  New Moon
    14  We   1:47 pm  Moon Apogee: 406100 km
    16  Fr   1:53 am  Moon Ascending Node
    17  Sa   8:09 am  Moon-Mars: 0.1° N, 
                         Occultation Africa-Asia
    18  Su  12:02 pm  Moon North Dec.: 25.5° N
    18  Su   9:31 pm  Mercury Superior Conj.
    20  Tu   2:59 am  First Quarter
    20  Tu   2:25 pm  Moon-Beehive: 3° S
    22  Th   8:16 am  Lyrid Shower: ZHR = 20
    26  Mo  11:31 pm  Full Moon - Supermoon
    27  Tu  11:24 am  Moon Perigee: 357400 km
    29  Th   5:17 am  Moon Descending Node
    30  Fr   5:15 pm  Uranus Conjunction
May  1  Sa            Venus: 9.4° E

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

Sun and Moon Rising and Setting Events

              Ephemeris of Sky Events for Interlochen/TC
April, 2021    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Thu  1| 07:23a  08:10p  12:47 | 09:15p  06:18a |      Rise 01:29a   76%|
|Fri  2| 07:21a  08:12p  12:50 | 09:17p  06:16a |      Rise 02:42a   66%|
|Sat  3| 07:19a  08:13p  12:53 | 09:18p  06:14a |      Rise 03:44a   55%|
+------+-----------------------+----------------+-----------------------+
|Sun  4| 07:17a  08:14p  12:56 | 09:19p  06:12a |L Qtr Rise 04:35a   44%|
|Mon  5| 07:15a  08:15p  13:00 | 09:21p  06:10a |      Rise 05:15a   33%|
|Tue  6| 07:13a  08:17p  13:03 | 09:22p  06:08a |      Rise 05:48a   24%|
|Wed  7| 07:12a  08:18p  13:06 | 09:24p  06:06a |      Rise 06:14a   16%|
|Thu  8| 07:10a  08:19p  13:09 | 09:25p  06:04a |      Rise 06:37a    9%|
|Fri  9| 07:08a  08:20p  13:12 | 09:27p  06:02a |      Rise 06:57a    4%|
|Sat 10| 07:06a  08:22p  13:15 | 09:28p  06:00a |      Rise 07:17a    1%|
+------+-----------------------+----------------+-----------------------+
|Sun 11| 07:05a  08:23p  13:18 | 09:30p  05:58a |New   Set  08:03p    0%|
|Mon 12| 07:03a  08:24p  13:21 | 09:31p  05:56a |      Set  09:05p    1%|
|Tue 13| 07:01a  08:25p  13:24 | 09:32p  05:54a |      Set  10:08p    3%|
|Wed 14| 06:59a  08:27p  13:27 | 09:34p  05:52a |      Set  11:11p    7%|
|Thu 15| 06:58a  08:28p  13:30 | 09:35p  05:50a |      Set  12:14a   13%|
|Fri 16| 06:56a  08:29p  13:33 | 09:37p  05:48a |      Set  01:15a   20%|
|Sat 17| 06:54a  08:30p  13:36 | 09:38p  05:46a |      Set  02:12a   28%|
+------+-----------------------+----------------+-----------------------+
|Sun 18| 06:52a  08:32p  13:39 | 09:40p  05:44a |      Set  03:03a   37%|
|Mon 19| 06:51a  08:33p  13:42 | 09:41p  05:42a |      Set  03:47a   47%|
|Tue 20| 06:49a  08:34p  13:44 | 09:43p  05:40a |F Qtr Set  04:24a   57%|
|Wed 21| 06:47a  08:35p  13:47 | 09:45p  05:38a |      Set  04:56a   67%|
|Thu 22| 06:46a  08:37p  13:50 | 09:46p  05:37a |      Set  05:24a   77%|
|Fri 23| 06:44a  08:38p  13:53 | 09:48p  05:35a |      Set  05:49a   86%|
|Sat 24| 06:43a  08:39p  13:56 | 09:49p  05:33a |      Set  06:14a   93%|
+------+-----------------------+----------------+-----------------------+
|Sun 25| 06:41a  08:40p  13:59 | 09:51p  05:31a |      Set  06:39a   98%|
|Mon 26| 06:39a  08:41p  14:02 | 09:52p  05:29a |Full  Rise 08:19p  100%|
|Tue 27| 06:38a  08:43p  14:04 | 09:54p  05:27a |      Rise 09:43p   99%|
|Wed 28| 06:36a  08:44p  14:07 | 09:55p  05:25a |      Rise 11:06p   95%|
|Thu 29| 06:35a  08:45p  14:10 | 09:57p  05:23a |      Rise 12:25a   88%|
|Fri 30| 06:33a  08:46p  14:13 | 09:59p  05:22a |      Rise 01:34a   80%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

02/01/2021 – Ephemeris – Previewing February Skies

This is Ephemeris for Monday, February 1st. Today the Sun will be up for 9 hours and 50 minutes, setting at 5:51, and it will rise tomorrow at 8:00. The Moon, 3 days before last quarter, will rise at 10:33 this evening. | February is the shortest month, even so the daylight hours throughout the month will be getting longer. Daylight hours will increase from 9 hours and 50 minutes today to 11 hours and 7 minutes on the 28th. The sunrise time will decrease from 8:01 today to 7:21 at months end. The sunset times will increase from 5:51 today to 6:29 on the 28th. Along with that the altitude of the Sun at noon will increase from 28.4 degrees today to 37.6 degrees at month’s end. It will be a degree lower for folks in the Straits area because they are a degree of latitude farther north. Local noon, by the way for Interlochen and Traverse City is about 12:56 p.m.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Star Chart for February 2021 (9 p.m. EST February 15, 2021). Created using my LookingUp program. Click on image to enlarge.

The planets and stars are plotted for the 15th at 9 p.m. EST in the evening and 6 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere (rotating star finder) you may have to set it to 1 hour 45 minutes earlier than the current time.

Note the chart times of 9 p.m. and 6 a.m. are for the 15th. For each week before the 15th add ½ hour (28 minutes if you’re picky). For each week after the 15th subtract ½ hour. The planet positions are updated each Wednesday on this blog. For planet positions on dates other than the 15th, check the Wednesday planet posts on this blog.

February Morning Star Chart

Star Chart for February mornings 2021 (6 a.m. EST February 15, 2021). Created using my LookingUp program. Click on image to enlarge.

For a list of constellation names to go with the abbreviations click here.

• Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
• Follow the arc of the handle of the Big Dipper to the star Arcturus, and
• Extend like a spike to Spica,
• The Summer Triangle is in red.

Twilight Limits, Nautical and Astronomical

			EST
	Morning twilight		Evening twilight		Dark night		Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2021-02-01	6h22m	6h56m	18h56m	19h30m	19h30m	22h33m	0.78
2021-02-02	6h21m	6h55m	18h57m	19h31m	19h31m	23h48m	0.67
2021-02-03	6h20m	6h54m	18h59m	19h33m	19h33m	–	0.56
2021-02-04	6h19m	6h53m	19h00m	19h34m	19h34m	1h03m	0.45
2021-02-05	6h18m	6h52m	19h01m	19h35m	19h35m	2h20m	0.34
2021-02-06	6h16m	6h50m	19h02m	19h36m	19h36m	3h35m	0.23
2021-02-07	6h15m	6h49m	19h04m	19h38m	19h38m	4h48m	0.15
2021-02-08	6h14m	6h48m	19h05m	19h39m	19h39m	5h54m	0.08
2021-02-09	6h13m	6h47m	19h06m	19h40m	19h40m	6h13m	0.03
2021-02-10	6h12m	6h46m	19h08m	19h41m	19h41m	6h12m	0
2021-02-11	6h10m	6h44m	19h09m	19h43m	19h43m	6h10m	0
2021-02-12	6h09m	6h43m	19h10m	19h44m	19h44m	6h09m	0.02
2021-02-13	6h08m	6h42m	19h11m	19h45m	20h14m	6h08m	0.06
2021-02-14	6h06m	6h40m	19h13m	19h47m	21h19m	6h06m	0.12
2021-02-15	6h05m	6h39m	19h14m	19h48m	22h22m	6h05m	0.19
2021-02-16	6h04m	6h37m	19h15m	19h49m	23h25m	6h04m	0.27
2021-02-17	6h02m	6h36m	19h17m	19h50m	–	6h02m	0.35
2021-02-18	6h01m	6h34m	19h18m	19h52m	0h27m	6h01m	0.45
2021-02-19	5h59m	6h33m	19h19m	19h53m	1h30m	5h59m	0.54
2021-02-20	5h58m	6h32m	19h21m	19h54m	2h33m	5h58m	0.64
2021-02-21	5h56m	6h30m	19h22m	19h56m	3h35m	5h56m	0.73
2021-02-22	5h55m	6h28m	19h23m	19h57m	4h34m	5h55m	0.81
2021-02-23	5h53m	6h27m	19h24m	19h58m	5h28m	5h53m	0.89
2021-02-24	5h52m	6h25m	19h26m	19h59m	–	–	0.94
2021-02-25	5h50m	6h24m	19h27m	20h01m	–	–	0.98
2021-02-26	5h48m	6h22m	19h28m	20h02m	–	–	1
2021-02-27	5h47m	6h20m	19h30m	20h03m	–	–	0.99
2021-02-28	5h45m	6h19m	19h31m	20h05m	20h05m	20h16m	0.95

Twilight calendar was generated using Cartes du Ciel (Sky Charts).

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2019/09/27/

NASA Calendar of Planetary Events

Date         Time     Event
Feb  1  Mo            Venus: 13° W
     3  We   2:33 pm  Moon Perigee: 370,100 km
     4  Th  12:37 pm  Last Quarter
     6  Sa   7:29 pm  Moon Descending Node
     8  Mo   8:39 am  Mercury Inferior Conjunction
     8  Mo  10:34 am  Moon South Dec.: 25° S
    11  Th   2:06 pm  New Moon
    18  Th   5:22 am  Moon Apogee: 404,500 km
    18  Th   5:47 pm  Moon-Mars: 4.1° N
    19  Fr   1:47 pm  First Quarter
    20  Sa   8:44 pm  Moon Ascending Node
    22  Mo   7:12 pm  Moon North Dec.: 25.1° N
    23  Tu   2:38 am  Mercury-Saturn: 4° N
    24  We   7:16 pm  Moon-Beehive: 2.5° S
    27  Sa   3:17 am  Full Moon

All event times are given for UTC-5:00: Eastern Standard or Daylight Time

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html

If you go to the above site you can print out a list like the above for the entire year or calendar pages for your time zone.

Sun and Moon Rising and Setting Events

LU                  Ephemeris of Sky Events for Interlochen/TC
February, 2021    Local time zone: EST
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Mon  1| 08:01a  05:51p  09:50 | 06:57p  06:55a |      Rise 10:33p   79%|
|Tue  2| 08:00a  05:53p  09:53 | 06:59p  06:54a |      Rise 11:48p   69%|
|Wed  3| 07:59a  05:54p  09:55 | 07:00p  06:53a |      Rise 01:03a   58%|
|Thu  4| 07:57a  05:56p  09:58 | 07:01p  06:52a |L Qtr Rise 02:19a   47%|
|Fri  5| 07:56a  05:57p  10:00 | 07:03p  06:51a |      Rise 03:35a   36%|
|Sat  6| 07:55a  05:59p  10:03 | 07:04p  06:50a |      Rise 04:48a   25%|
+------+-----------------------+----------------+-----------------------+
|Sun  7| 07:54a  06:00p  10:06 | 07:05p  06:48a |      Rise 05:53a   16%|
|Mon  8| 07:52a  06:01p  10:09 | 07:06p  06:47a |      Rise 06:49a    9%|
|Tue  9| 07:51a  06:03p  10:11 | 07:08p  06:46a |      Rise 07:35a    4%|
|Wed 10| 07:49a  06:04p  10:14 | 07:09p  06:45a |      Rise 08:11a    1%|
|Thu 11| 07:48a  06:06p  10:17 | 07:10p  06:43a |New   Set  05:57p    0%|
|Fri 12| 07:47a  06:07p  10:20 | 07:12p  06:42a |      Set  07:07p    2%|
|Sat 13| 07:45a  06:08p  10:23 | 07:13p  06:41a |      Set  08:14p    5%|
+------+-----------------------+----------------+-----------------------+
|Sun 14| 07:44a  06:10p  10:26 | 07:14p  06:39a |      Set  09:19p   11%|
|Mon 15| 07:42a  06:11p  10:29 | 07:15p  06:38a |      Set  10:22p   17%|
|Tue 16| 07:41a  06:13p  10:32 | 07:17p  06:37a |      Set  11:24p   25%|
|Wed 17| 07:39a  06:14p  10:34 | 07:18p  06:35a |      Set  12:27a   34%|
|Thu 18| 07:38a  06:15p  10:37 | 07:19p  06:34a |      Set  01:30a   43%|
|Fri 19| 07:36a  06:17p  10:40 | 07:21p  06:32a |F Qtr Set  02:32a   52%|
|Sat 20| 07:34a  06:18p  10:43 | 07:22p  06:31a |      Set  03:34a   61%|
+------+-----------------------+----------------+-----------------------+
|Sun 21| 07:33a  06:20p  10:46 | 07:23p  06:29a |      Set  04:33a   71%|
|Mon 22| 07:31a  06:21p  10:49 | 07:25p  06:28a |      Set  05:28a   79%|
|Tue 23| 07:30a  06:22p  10:52 | 07:26p  06:26a |      Set  06:15a   87%|
|Wed 24| 07:28a  06:24p  10:55 | 07:27p  06:25a |      Set  06:56a   93%|
|Thu 25| 07:26a  06:25p  10:58 | 07:28p  06:23a |      Set  07:30a   98%|
|Fri 26| 07:24a  06:26p  11:01 | 07:30p  06:21a |      Set  07:59a  100%|
|Sat 27| 07:23a  06:28p  11:05 | 07:31p  06:20a |Full  Rise 06:59p   99%|
+------+-----------------------+----------------+-----------------------+
|Sun 28| 07:21a  06:29p  11:08 | 07:32p  06:18a |      Rise 08:16p   96%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Created using my LookingUp for DOS output as HTML.