Bob Moler's Ephemeris Blog

This is Bob Moler with Ephemeris for Friday, January 31st. Today the Sun will be up for 9 hours and 47 minutes, setting at 5:50, and it will rise tomorrow at 8:01. The Moon, 2 days past new, will set at 8:39 this evening.

January was a wild and crazy month, let’s hope February is short and sweet. Well, at least it’ll be short. The daylight hours throughout the month will be getting longer. Daylight hours will increase from 9 hours and 50 minutes tomorrow to 11 hours and 8 minutes on the 28th. The sunrise time will decrease from 8:01 today to 7:21 at month’s end. The sunset times will increase from 5:51 tomorrow to 6:29 on the 28th. Along with that the altitude of the Sun at noon will increase from 28.4 degrees tomorrow 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 Moon will be near Saturn tonight.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.

Addendum

February Evening Star Chart

The planets and stars are plotted for the 14th at 9 PM EST in the evening and 6 AM 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 45 minutes or one hour 45 minutes (Daylight Time) earlier than the current time.

Note the chart times of 9 p.m. and 6 a.m. are for the 14th and 15th. For each week before these dates, add ½ hour (28 minutes if you’re picky). For each week after, subtract ½ hour. Planet positions on dates other than the 15th can be found in the Wednesday planet posts on this blog.

February 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.
• 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.
2025-02-01	6h22m	6h56m	19h00m	19h35m	21h58m	6h22m	0.17
2025-02-02	6h21m	6h55m	19h02m	19h36m	23h16m	6h21m	0.27
2025-02-03	6h20m	6h54m	19h03m	19h37m	–	6h20m	0.37
2025-02-04	6h19m	6h53m	19h04m	19h38m	0h35m	6h19m	0.49
2025-02-05	6h18m	6h52m	19h05m	19h39m	1h55m	6h18m	0.6
2025-02-06	6h17m	6h51m	19h07m	19h41m	3h15m	6h17m	0.71
2025-02-07	6h16m	6h49m	19h08m	19h42m	4h30m	6h16m	0.8
2025-02-08	6h14m	6h48m	19h09m	19h43m	5h36m	6h14m	0.88
2025-02-09	6h13m	6h47m	19h11m	19h44m	–	–	0.94
2025-02-10	6h12m	6h46m	19h12m	19h46m	–	–	0.98
2025-02-11	6h11m	6h44m	19h13m	19h47m	–	–	1
2025-02-12	6h09m	6h43m	19h14m	19h48m	–	–	1
2025-02-13	6h08m	6h42m	19h16m	19h50m	–	–	0.97
2025-02-14	6h07m	6h40m	19h17m	19h51m	19h51m	20h35m	0.93
2025-02-15	6h05m	6h39m	19h18m	19h52m	19h52m	21h39m	0.88
2025-02-16	6h04m	6h38m	19h20m	19h53m	19h53m	22h43m	0.81
2025-02-17	6h02m	6h36m	19h21m	19h55m	19h55m	23h47m	0.73
2025-02-18	6h01m	6h35m	19h22m	19h56m	19h56m	–	0.64
2025-02-19	6h00m	6h33m	19h23m	19h57m	19h57m	0h53m	0.55
2025-02-20	5h58m	6h32m	19h25m	19h58m	19h58m	2h00m	0.46
2025-02-21	5h56m	6h30m	19h26m	20h00m	20h00m	3h07m	0.36
2025-02-22	5h55m	6h29m	19h27m	20h01m	20h01m	4h10m	0.26
2025-02-23	5h53m	6h27m	19h29m	20h02m	20h02m	5h06m	0.18
2025-02-24	5h52m	6h25m	19h30m	20h04m	20h04m	5h52m	0.1
2025-02-25	5h50m	6h24m	19h31m	20h05m	20h05m	5h50m	0.04
2025-02-26	5h48m	6h22m	19h33m	20h06m	20h06m	5h48m	0.01
2025-02-27	5h47m	6h21m	19h34m	20h08m	20h08m	5h47m	0
2025-02-28	5h45m	6h19m	19h35m	20h09m	20h09m	5h45m	0.02

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  Sa            Venus: 45° E
     1  Sa   3:27 PM  Moon-Venus: 2.4° N
     1  Sa   5:06 PM  Moon Ascending Node
     1  Sa   9:43 PM  Moon Perigee: 367500 km
     5  We   3:02 AM  First Quarter
     6  Th   1:43 AM  Moon-Pleiades: 0.5° S
     8  Sa   5:40 AM  Moon North Dec.: 28.6° N
     9  Su   6:57 AM  Mercury Superior Conj.
     9  Su   2:36 PM  Moon-Mars: 0.8° S
    10  Mo  12:19 AM  Moon-Pollux: 2.2° N
    11  Tu  12:03 AM  Moon-Beehive: 2.7° S
    12  We   8:53 AM  Full Moon
    12  We   6:21 PM  Moon-Regulus: 2.3° S
    15  Sa   1:53 AM  Moon Descending Node
    17  Mo   7:01 AM  Moon-Spica: 0.3° N
    17  Mo   8:11 PM  Moon Apogee: 404900 km
    20  Th  12:32 PM  Last Quarter
    21  Fr   3:21 AM  Moon-Antares: 0.5° N
    22  Sa   5:32 PM  Moon South Dec.: 28.7° S
    27  Th   7:45 PM  New Moon
Mar  1  Sa            Venus: 30.4° E
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
February, 2025    Local time zone: EST
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Sat  1| 08:01a  05:51p  09:50 | 06:58p  06:55a |      Set  09:57p   15%|
+------+-----------------------+----------------+-----------------------+
|Sun  2| 08:00a  05:53p  09:53 | 06:59p  06:54a |      Set  11:15p   24%|
|Mon  3| 07:59a  05:54p  09:55 | 07:00p  06:53a |      Set  12:35a   35%|
|Tue  4| 07:57a  05:56p  09:58 | 07:01p  06:52a |      Set  01:55a   46%|
|Wed  5| 07:56a  05:57p  10:01 | 07:03p  06:51a |F Qtr Set  03:14a   57%|
|Thu  6| 07:55a  05:59p  10:03 | 07:04p  06:50a |      Set  04:30a   68%|
|Fri  7| 07:54a  06:00p  10:06 | 07:05p  06:48a |      Set  05:36a   78%|
|Sat  8| 07:52a  06:01p  10:09 | 07:06p  06:47a |      Set  06:29a   86%|
+------+-----------------------+----------------+-----------------------+
|Sun  9| 07:51a  06:03p  10:12 | 07:08p  06:46a |      Set  07:10a   93%|
|Mon 10| 07:49a  06:04p  10:14 | 07:09p  06:45a |      Set  07:42a   97%|
|Tue 11| 07:48a  06:06p  10:17 | 07:10p  06:43a |      Set  08:06a  100%|
|Wed 12| 07:47a  06:07p  10:20 | 07:12p  06:42a |Full  Rise 06:21p  100%|
|Thu 13| 07:45a  06:08p  10:23 | 07:13p  06:41a |      Rise 07:29p   98%|
|Fri 14| 07:44a  06:10p  10:26 | 07:14p  06:39a |      Rise 08:34p   94%|
|Sat 15| 07:42a  06:11p  10:29 | 07:16p  06:38a |      Rise 09:38p   89%|
+------+-----------------------+----------------+-----------------------+
|Sun 16| 07:41a  06:13p  10:32 | 07:17p  06:37a |      Rise 10:42p   82%|
|Mon 17| 07:39a  06:14p  10:35 | 07:18p  06:35a |      Rise 11:47p   75%|
|Tue 18| 07:38a  06:15p  10:37 | 07:19p  06:34a |      Rise 12:52a   66%|
|Wed 19| 07:36a  06:17p  10:40 | 07:21p  06:32a |      Rise 01:59a   57%|
|Thu 20| 07:34a  06:18p  10:43 | 07:22p  06:31a |L Qtr Rise 03:06a   47%|
|Fri 21| 07:33a  06:20p  10:46 | 07:23p  06:29a |      Rise 04:09a   38%|
|Sat 22| 07:31a  06:21p  10:49 | 07:25p  06:28a |      Rise 05:06a   28%|
+------+-----------------------+----------------+-----------------------+
|Sun 23| 07:29a  06:22p  10:52 | 07:26p  06:26a |      Rise 05:53a   19%|
|Mon 24| 07:28a  06:24p  10:55 | 07:27p  06:24a |      Rise 06:30a   12%|
|Tue 25| 07:26a  06:25p  10:59 | 07:28p  06:23a |      Rise 07:00a    6%|
|Wed 26| 07:24a  06:26p  11:02 | 07:30p  06:21a |      Rise 07:25a    2%|
|Thu 27| 07:23a  06:28p  11:05 | 07:31p  06:20a |New   Set  06:14p    0%|
|Fri 28| 07:21a  06:29p  11:08 | 07:32p  06:18a |      Set  07:34p    1%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise

Created using my LookingUp for MS-DOS app.