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01/01/2021 – Ephemeris – The first few day of January have two annual astronomical events

January 1, 2021 1 comment

Note: With New Year’s Day followed by the weekend I’m postponing the January preview program to Monday the 4th, however, the Month Preview addendum will be added to the post today.

Happy New Year, this is Bob Moler with Ephemeris for New Year’s Day, Friday, January 1st 2021. The Sun will rise at 8:20. It’ll be up for 8 hours and 53 minutes, setting at 5:13. The Moon, 3 days past full, will rise at 7:51 this evening.

It happens that a lot of astronomical events occur in the first few days of January, that I’ll cover these now and talk about the rest of the month on Monday. Tomorrow, the second, at 3:59 am the Earth will be its closest to the Sun at 91.4 million miles (147.0 million kilometers). The only real effect is that it makes winter the shortest season, four days shorter than summer because the Earth moves fastest  when closest to the Sun. On Saturday evening the 2nd will see the peak of the Quadrantid meteor shower for a short time before the bright Moon rises at 9 p.m. the radiant point for this shower is low in the north, from an obsolete constellation of the Mural Quadrant located off the handle of the Big Dipper. The bright waning gibbous Moon will curtail the morning display of the shower when the radiant is higher. January 2nd also the latest sunrise. Later in January we will have brighter early mornings again.

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

Addendum

January Evening Star Chart

January Evening Star Chart

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

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. The brilliant planet Venus will enter the sky at the chart time during the latter half of the month in the southwest.  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).

January Morning Star Chart

January Morning Star Chart January Morning Star Chart

Star Chart for January mornings 2021 (6 a.m. EST January 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.
  • QuadR on the star charts is the radiant of the Quadrantid meteor shower which peaks on the 3rd, but is best seen in the early evening hours of the 2nd before the Moon rises.

Twilight Limits, Nautical and Astronomical

EST
Morning twilight Evening twilight Dark night Moon
Date Astro. Nautical Nautical Astro. Start End Illum.
2021-01-01 6h35m 7h10m 18h22m 18h57m 18h57m 19h51m 0.9
2021-01-02 6h35m 7h11m 18h23m 18h58m 18h58m 21h03m 0.83
2021-01-03 6h35m 7h11m 18h24m 18h59m 18h59m 22h16m 0.74
2021-01-04 6h35m 7h11m 18h24m 19h00m 19h00m 23h29m 0.64
2021-01-05 6h35m 7h11m 18h25m 19h01m 19h01m 0.52
2021-01-06 6h35m 7h10m 18h26m 19h02m 19h02m 0h42m 0.41
2021-01-07 6h35m 7h10m 18h27m 19h02m 19h02m 1h57m 0.3
2021-01-08 6h35m 7h10m 18h28m 19h03m 19h03m 3h13m 0.2
2021-01-09 6h35m 7h10m 18h29m 19h04m 19h04m 4h31m 0.11
2021-01-10 6h35m 7h10m 18h30m 19h05m 19h05m 5h48m 0.05
2021-01-11 6h35m 7h10m 18h31m 19h06m 19h06m 6h35m 0.01
2021-01-12 6h34m 7h09m 18h32m 19h07m 19h07m 6h34m 0
2021-01-13 6h34m 7h09m 18h33m 19h08m 19h08m 6h34m 0.01
2021-01-14 6h34m 7h09m 18h35m 19h09m 19h09m 6h34m 0.05
2021-01-15 6h33m 7h08m 18h36m 19h11m 20h17m 6h33m 0.1
2021-01-16 6h33m 7h08m 18h37m 19h12m 21h25m 6h33m 0.17
2021-01-17 6h32m 7h07m 18h38m 19h13m 22h31m 6h32m 0.26
2021-01-18 6h32m 7h07m 18h39m 19h14m 23h34m 6h32m 0.34
2021-01-19 6h31m 7h06m 18h40m 19h15m 6h31m 0.44
2021-01-20 6h31m 7h06m 18h41m 19h16m 0h36m 6h31m 0.53
2021-01-21 6h30m 7h05m 18h43m 19h17m 1h38m 6h30m 0.62
2021-01-22 6h30m 7h04m 18h44m 19h18m 2h40m 6h30m 0.71
2021-01-23 6h29m 7h04m 18h45m 19h20m 3h43m 6h29m 0.8
2021-01-24 6h28m 7h03m 18h46m 19h21m 4h47m 6h28m 0.87
2021-01-25 6h28m 7h02m 18h47m 19h22m 5h48m 6h28m 0.93
2021-01-26 6h27m 7h01m 18h49m 19h23m 0.97
2021-01-27 6h26m 7h01m 18h50m 19h24m 1
2021-01-28 6h25m 7h00m 18h51m 19h25m 1
2021-01-29 6h24m 6h59m 18h52m 19h27m 0.98
2021-01-30 6h24m 6h58m 18h54m 19h28m 19h28m 20h04m 0.93
2021-01-31 6h23m 6h57m 18h55m 19h29m 19h29m 21h18m 0.86

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

Jan  1  Fr            Venus: 20.2° W
     1  Fr   2:05 am  Moon-Beehive: 2.5° S
     2  Sa   3:59 am  Perihelion: 0.9833 AU
     3  Su   9:47 am  Quadrantid Shower: ZHR = 120
     6  We   4:37 am  Last Quarter
     9  Sa  10:39 am  Moon Perigee: 367400 km
    10  Su   3:14 pm  Moon Descending Node
    11  Mo   3:11 pm  Moon-Venus: 1.5° N
    12  Tu   3:18 am  Moon South Dec.: 24.9° S
    13  We  12:00 am  New Moon
    20  We   4:02 pm  First Quarter
    21  Th   8:11 am  Moon Apogee: 404400 km
    23  Sa   8:59 pm  Mercury Elongation: 18.6° E
    23  Sa   9:26 pm  Saturn Conjunction with the Sun
    24  Su   4:47 pm  Moon Ascending Node
    26  Tu  10:39 am  Moon North Dec.: 24.9° N
    28  Th   9:50 am  Moon-Beehive: 2.4° S
    28  Th   2:16 pm  Full Moon
    28  Th   7:51 pm  Jupiter Conjunction with the Sun
Feb  1  Mo            Venus: 13° W

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
January, 2021    Local time zone: EST
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Fri  1| 08:20a  05:13p  08:53 | 06:23p  07:09a |      Rise 07:51p   91%|
|Sat  2| 08:20a  05:14p  08:54 | 06:24p  07:09a |      Rise 09:03p   84%|
+------+-----------------------+----------------+-----------------------+
|Sun  3| 08:20a  05:15p  08:55 | 06:25p  07:10a |      Rise 10:16p   76%|
|Mon  4| 08:20a  05:16p  08:56 | 06:26p  07:10a |      Rise 11:29p   66%|
|Tue  5| 08:19a  05:17p  08:57 | 06:27p  07:10a |      Rise 12:42a   55%|
|Wed  6| 08:19a  05:18p  08:58 | 06:28p  07:09a |L Qtr Rise 01:57a   43%|
|Thu  7| 08:19a  05:19p  08:59 | 06:29p  07:09a |      Rise 03:13a   32%|
|Fri  8| 08:19a  05:20p  09:01 | 06:30p  07:09a |      Rise 04:31a   22%|
|Sat  9| 08:19a  05:21p  09:02 | 06:31p  07:09a |      Rise 05:48a   13%|
+------+-----------------------+----------------+-----------------------+
|Sun 10| 08:18a  05:22p  09:04 | 06:32p  07:09a |      Rise 07:01a    6%|
|Mon 11| 08:18a  05:23p  09:05 | 06:33p  07:09a |      Rise 08:05a    2%|
|Tue 12| 08:17a  05:25p  09:07 | 06:34p  07:08a |      Rise 08:58a    0%|
|Wed 13| 08:17a  05:26p  09:08 | 06:35p  07:08a |New   Set  05:55p    1%|
|Thu 14| 08:16a  05:27p  09:10 | 06:36p  07:08a |      Set  07:06p    4%|
|Fri 15| 08:16a  05:28p  09:12 | 06:37p  07:07a |      Set  08:17p    9%|
|Sat 16| 08:15a  05:30p  09:14 | 06:38p  07:07a |      Set  09:25p   16%|
+------+-----------------------+----------------+-----------------------+
|Sun 17| 08:15a  05:31p  09:16 | 06:39p  07:06a |      Set  10:30p   24%|
|Mon 18| 08:14a  05:32p  09:18 | 06:40p  07:06a |      Set  11:34p   33%|
|Tue 19| 08:13a  05:33p  09:20 | 06:42p  07:05a |      Set  12:36a   42%|
|Wed 20| 08:13a  05:35p  09:22 | 06:43p  07:05a |F Qtr Set  01:38a   51%|
|Thu 21| 08:12a  05:36p  09:24 | 06:44p  07:04a |      Set  02:40a   60%|
|Fri 22| 08:11a  05:37p  09:26 | 06:45p  07:03a |      Set  03:43a   69%|
|Sat 23| 08:10a  05:39p  09:28 | 06:46p  07:03a |      Set  04:46a   78%|
+------+-----------------------+----------------+-----------------------+
|Sun 24| 08:09a  05:40p  09:30 | 06:48p  07:02a |      Set  05:48a   85%|
|Mon 25| 08:08a  05:42p  09:33 | 06:49p  07:01a |      Set  06:46a   92%|
|Tue 26| 08:07a  05:43p  09:35 | 06:50p  07:00a |      Set  07:38a   96%|
|Wed 27| 08:06a  05:44p  09:37 | 06:51p  07:00a |      Set  08:23a   99%|
|Thu 28| 08:05a  05:46p  09:40 | 06:52p  06:59a |Full  Rise 05:37p  100%|
|Fri 29| 08:04a  05:47p  09:42 | 06:54p  06:58a |      Rise 06:49p   98%|
|Sat 30| 08:03a  05:49p  09:45 | 06:55p  06:57a |      Rise 08:04p   94%|
+------+-----------------------+----------------+-----------------------+
|Sun 31| 08:02a  05:50p  09:47 | 06:56p  06:56a |      Rise 09:18p   88%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.