Archive

Archive for September 30, 2021

09/30/2021 – Ephemeris – Previewing October skies

September 30, 2021 Comments off

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 October

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 October Mornings

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.

Categories: Ephemeris Program, Month preview Tags: