Bob Moler's Ephemeris Blog

This post didn’t make it into a radio program, so enjoy.

We start a new year and a month. The daylight hours start slowly getting longer and will accelerate during the month. Daylight hours in Interlochen and Traverse City will increase from 8 hours and 52 minutes on the 1st to 9 hours and 46 minutes on the 31st. The sunrise time will decrease from 8:20 am on the 1st to 8:03 am at month’s end. The sunset times will increase from 5:12 pm on the 1st to 5:49 pm on the 31st. Along with that the altitude of the sun at noon will increase from 22 degrees tomorrow to nearly 28 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 around 12:51 p.m. in January.

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.

January Evening Star Chart

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

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 4th at 3:20 a.m. EST (8:20 UT).

Twilight Limits, Nautical and Astronomical

			EST
	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2024-01-01	6h35m	7h11m	18h22m	19h01m	19h01m	22h59m	0.68
2024-01-02	6h35m	7h11m	18h22m	19h02m	19h02m	–	0.59
2024-01-03	6h35m	7h11m	18h23m	19h03m	19h03m	0h01m	0.50
2024-01-04	6h35m	7h11m	18h24m	19h03m	19h03m	1h05m	0.40
2024-01-05	6h35m	7h11m	18h25m	19h04m	19h04m	2h10m	0.30
2024-01-06	6h35m	7h11m	18h26m	19h05m	19h05m	3h19m	0.21
2024-01-07	6h35m	7h11m	18h27m	19h06m	19h06m	4h31m	0.13
2024-01-08	6h35m	7h11m	18h28m	19h07m	19h07m	5h45m	0.07
2024-01-09	6h35m	7h10m	18h29m	19h08m	19h08m	6h35m	0.02
2024-01-10	6h35m	7h10m	18h30m	19h09m	19h09m	6h35m	0.00
2024-01-11	6h35m	7h10m	18h31m	19h10m	19h10m	6h35m	0.01
2024-01-12	6h35m	7h10m	18h32m	19h11m	19h11m	6h35m	0.04
2024-01-13	6h34m	7h09m	18h33m	19h12m	20h14m	6h34m	0.10
2024-01-14	6h34m	7h09m	18h34m	19h13m	21h36m	6h34m	0.18
2024-01-15	6h34m	7h09m	18h35m	19h14m	22h55m	6h34m	0.28
2024-01-16	6h33m	7h08m	18h36m	19h15m	–	6h33m	0.39
2024-01-17	6h33m	7h08m	18h37m	19h16m	0h12m	6h33m	0.51
2024-01-18	6h33m	7h07m	18h39m	19h17m	1h28m	6h33m	0.62
2024-01-19	6h32m	7h07m	18h40m	19h18m	2h44m	6h32m	0.72
2024-01-20	6h32m	7h06m	18h41m	19h20m	3h59m	6h32m	0.81
2024-01-21	6h31m	7h06m	18h42m	19h21m	5h12m	6h31m	0.88
2024-01-22	6h30m	7h05m	18h43m	19h22m	6h18m	6h30m	0.94
2024-01-23	6h30m	7h04m	18h44m	19h23m	–	–	0.98
2024-01-24	6h29m	7h04m	18h46m	19h24m	–	–	1.00
2024-01-25	6h28m	7h03m	18h47m	19h25m	–	–	1.00
2024-01-26	6h28m	7h02m	18h48m	19h26m	–	–	0.98
2024-01-27	6h27m	7h01m	18h49m	19h28m	19h28m	19h44m	0.95
2024-01-28	6h26m	7h00m	18h51m	19h29m	19h29m	20h48m	0.90
2024-01-29	6h25m	7h00m	18h52m	19h30m	19h30m	21h51m	0.83
2024-01-30	6h24m	6h59m	18h53m	19h31m	19h31m	22h53m	0.76
2024-01-31	6h24m	6h58m	18h54m	19h32m	19h32m	23h57m	0.67

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
Jan  1  Mo            Venus: 37.4° W
     1  Mo  10:28 am  Moon Apogee: 404900 km
     2  Tu   6:59 pm  Perihelion:  .9833 AU
     3  We  10:30 pm  Last Quarter
     4  Th   4:15 am  Quadrantid Shower: ZHR = 120
     4  Th   1:52 pm  Moon Descending Node
     4  Th   6:06 pm  Moon-Spica: 2.2° S
     6  Sa   7:35 pm  Venus-Antares: 6.3° N
     8  Mo   9:24 am  Moon-Antares:  .8° S
     8  Mo   3:12 pm  Moon-Venus: 5.9° N
    10  We   2:04 am  Moon South Dec.: 28.2° S
    11  Th   6:57 am  New Moon
    12  Fr   8:59 am  Mercury Elongation: 23.5° W
    13  Sa   5:35 am  Moon Perigee: 362300 km
    14  Su   4:31 am  Moon-Saturn: 2.1° N
    17  We   9:05 am  Moon Ascending Node
    17  We  10:53 pm  First Quarter
    18  Th   3:40 pm  Moon-Jupiter: 2.9° S
    20  Sa   8:25 am  Moon-Pleiades:  .9° N
    22  Mo  10:44 pm  Moon North Dec.: 28.2° N
    24  We   2:00 pm  Moon-Pollux: 1.9° N
    25  Th  12:54 pm  Full Moon
    25  Th   3:04 pm  Moon-Beehive: 3.6° S
    27  Sa  10:48 am  Mercury-Mars:  .2° N
    29  Mo   3:14 am  Moon Apogee: 405800 km
    31  We   3:17 pm  Moon Descending Node
Feb  1  Th            Venus: 30.8° 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, 2024    Local time zone: EST
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Mon  1| 08:20a  05:12p  08:52 | 06:22p  07:09a |      Rise 10:58p   70%|
|Tue  2| 08:20a  05:13p  08:53 | 06:23p  07:09a |      Rise 12:01a   61%|
|Wed  3| 08:20a  05:14p  08:54 | 06:24p  07:09a |L Qtr Rise 01:04a   51%|
|Thu  4| 08:20a  05:15p  08:55 | 06:25p  07:10a |      Rise 02:10a   42%|
|Fri  5| 08:20a  05:16p  08:56 | 06:26p  07:10a |      Rise 03:18a   32%|
|Sat  6| 08:19a  05:17p  08:57 | 06:27p  07:09a |      Rise 04:30a   23%|
+------+-----------------------+----------------+-----------------------+
|Sun  7| 08:19a  05:18p  08:58 | 06:28p  07:09a |      Rise 05:45a   15%|
|Mon  8| 08:19a  05:19p  09:00 | 06:29p  07:09a |      Rise 06:58a    8%|
|Tue  9| 08:19a  05:20p  09:01 | 06:30p  07:09a |      Rise 08:04a    3%|
|Wed 10| 08:18a  05:21p  09:02 | 06:31p  07:09a |      Rise 08:59a    1%|
|Thu 11| 08:18a  05:23p  09:04 | 06:32p  07:09a |New   Set  05:25p    1%|
|Fri 12| 08:18a  05:24p  09:06 | 06:33p  07:09a |      Set  06:49p    3%|
|Sat 13| 08:17a  05:25p  09:07 | 06:34p  07:08a |      Set  08:14p    9%|
+------+-----------------------+----------------+-----------------------+
|Sun 14| 08:17a  05:26p  09:09 | 06:35p  07:08a |      Set  09:36p   17%|
|Mon 15| 08:16a  05:27p  09:11 | 06:36p  07:08a |      Set  10:55p   26%|
|Tue 16| 08:16a  05:29p  09:12 | 06:37p  07:07a |      Set  12:12a   37%|
|Wed 17| 08:15a  05:30p  09:14 | 06:38p  07:07a |F Qtr Set  01:28a   48%|
|Thu 18| 08:15a  05:31p  09:16 | 06:40p  07:06a |      Set  02:43a   59%|
|Fri 19| 08:14a  05:33p  09:18 | 06:41p  07:06a |      Set  03:59a   69%|
|Sat 20| 08:13a  05:34p  09:20 | 06:42p  07:05a |      Set  05:11a   79%|
+------+-----------------------+----------------+-----------------------+
|Sun 21| 08:12a  05:35p  09:22 | 06:43p  07:05a |      Set  06:17a   86%|
|Mon 22| 08:12a  05:37p  09:24 | 06:44p  07:04a |      Set  07:14a   93%|
|Tue 23| 08:11a  05:38p  09:27 | 06:45p  07:03a |      Set  08:00a   97%|
|Wed 24| 08:10a  05:39p  09:29 | 06:47p  07:03a |      Set  08:36a   99%|
|Thu 25| 08:09a  05:41p  09:31 | 06:48p  07:02a |Full  Rise 05:30p  100%|
|Fri 26| 08:08a  05:42p  09:33 | 06:49p  07:01a |      Rise 06:37p   98%|
|Sat 27| 08:07a  05:43p  09:36 | 06:50p  07:00a |      Rise 07:43p   95%|
+------+-----------------------+----------------+-----------------------+
|Sun 28| 08:06a  05:45p  09:38 | 06:52p  06:59a |      Rise 08:47p   91%|
|Mon 29| 08:05a  05:46p  09:41 | 06:53p  06:59a |      Rise 09:50p   84%|
|Tue 30| 08:04a  05:48p  09:43 | 06:54p  06:58a |      Rise 10:53p   77%|
|Wed 31| 08:03a  05:49p  09:46 | 06:55p  06:57a |      Rise 11:56p   69%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset
Generated using my LookingUp for DOS program.

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