Bob Moler's Ephemeris Blog

This is Ephemeris for Friday, May 1st. Today the Sun will be up for 14 hours and 15 minutes, setting at 8:47, and it will rise tomorrow at 6:31. The Moon, at full today, will rise at 9:17 this evening.

Before we look at the month of May’s skies, consider that it’s May Day, a Cross-Quarter day meaning that spring is about half over. Daylight hours in the Interlochen/Traverse City area will increase from 14 hours and 15 minutes today 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 60 degrees today to 67 degrees at month’s end. The altitude of the Sun in the Straits area will be a degree lower than that, but the length of daylight will be a few minutes longer. Local apparent noon this month, when the Sun passes due south, will be about 1:38 p.m. The Eta Aquariid meteor shower will reach its peak on the 5th, but will be hindered by the bright moon.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

May Evening Star Chart

The planets and stars are plotted for the 15th at 11 p.m. EDT in the evening and 4:30 a.m. on the 16th 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 4:30 a.m. are for the night of the15/16th. For each week before then add ½ hour (28 minutes if you’re picky). For each week after then, 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 their weekly locations.

May Morning Star Chart

Twilight Limits, Nautical and Astronomical

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.blog/2018/09/27/.

NASA Calendar of Planetary Events

May  1  Fr            Venus: 27.8° E
     1  Fr   1:23 PM  Full Moon
     1  Fr   8:59 PM  Venus-Aldebaran: 6.4° N
     3  Su  10:20 PM  Moon-Antares: 0.5° N
     4  Mo   6:30 PM  Moon Apogee: 405800 km
     5  Tu   4:16 AM  Eta Aquariid Shower: ZHR = 60
     5  Tu   7:35 AM  Moon South Dec.: 28.1° S
     9  Sa   5:11 PM  Last Quarter
    11  Mo  12:36 AM  Moon Ascending Node
    14  Th  10:15 AM  Mercury Superior Conjunction
    16  Sa   4:01 PM  New Moon
    17  Su   9:48 AM  Moon Perigee: 358100 km
    18  Mo   3:38 PM  Moon North Dec.: 28.1° N
    18  Mo   9:50 PM  Moon-Venus: 2.9° S
    20  We   8:39 AM  Moon-Jupiter: 3.1° S
    21  Th  10:39 AM  Moon-Beehive: 0.8° S
    22  Fr  11:56 AM  Uranus Conjunction
    23  Sa   2:40 AM  Moon-Regulus: 0°
    23  Sa   7:11 AM  First Quarter
    23  Sa  11:26 AM  Moon Descending Node
    27  We  10:09 AM  Moon-Spica: 2.1° N
    31  Su   4:32 AM  Moon-Antares: 0.4° N
    31  Su   4:45 AM  Full Moon
Jun  1  Mo            Venus: 35° 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, 2026    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Fri  1| 06:32a  08:47p  14:15 | 10:00p  05:20a |Full  Rise 09:17p  100%|
|Sat  2| 06:31a  08:49p  14:17 | 10:01p  05:18a |      Rise 10:24p   98%|
+------+-----------------------+----------------+-----------------------+
|Sun  3| 06:29a  08:50p  14:20 | 10:03p  05:17a |      Rise 11:28p   95%|
|Mon  4| 06:28a  08:51p  14:23 | 10:04p  05:15a |      Rise 12:25a   90%|
|Tue  5| 06:26a  08:52p  14:25 | 10:06p  05:13a |      Rise 01:15a   84%|
|Wed  6| 06:25a  08:53p  14:28 | 10:08p  05:11a |      Rise 01:55a   77%|
|Thu  7| 06:24a  08:55p  14:30 | 10:09p  05:10a |      Rise 02:28a   68%|
|Fri  8| 06:22a  08:56p  14:33 | 10:11p  05:08a |      Rise 02:55a   59%|
|Sat  9| 06:21a  08:57p  14:35 | 10:12p  05:06a |L Qtr Rise 03:18a   49%|
+------+-----------------------+----------------+-----------------------+
|Sun 10| 06:20a  08:58p  14:38 | 10:14p  05:05a |      Rise 03:38a   39%|
|Mon 11| 06:19a  08:59p  14:40 | 10:15p  05:03a |      Rise 03:57a   29%|
|Tue 12| 06:17a  09:01p  14:43 | 10:17p  05:02a |      Rise 04:16a   19%|
|Wed 13| 06:16a  09:02p  14:45 | 10:18p  05:00a |      Rise 04:37a   11%|
|Thu 14| 06:15a  09:03p  14:47 | 10:20p  04:58a |      Rise 05:02a    5%|
|Fri 15| 06:14a  09:04p  14:49 | 10:21p  04:57a |      Rise 05:34a    1%|
|Sat 16| 06:13a  09:05p  14:52 | 10:23p  04:56a |New   Set  09:36p    0%|
+------+-----------------------+----------------+-----------------------+
|Sun 17| 06:12a  09:06p  14:54 | 10:24p  04:54a |      Set  10:57p    2%|
|Mon 18| 06:11a  09:07p  14:56 | 10:26p  04:53a |      Set  12:07a    7%|
|Tue 19| 06:10a  09:08p  14:58 | 10:27p  04:51a |      Set  01:01a   15%|
|Wed 20| 06:09a  09:09p  15:00 | 10:29p  04:50a |      Set  01:41a   24%|
|Thu 21| 06:08a  09:11p  15:02 | 10:30p  04:49a |      Set  02:11a   34%|
|Fri 22| 06:07a  09:12p  15:04 | 10:32p  04:47a |      Set  02:35a   45%|
|Sat 23| 06:06a  09:13p  15:06 | 10:33p  04:46a |F Qtr Set  02:54a   56%|
+------+-----------------------+----------------+-----------------------+
|Sun 24| 06:05a  09:14p  15:08 | 10:34p  04:45a |      Set  03:12a   66%|
|Mon 25| 06:05a  09:15p  15:10 | 10:36p  04:44a |      Set  03:30a   75%|
|Tue 26| 06:04a  09:16p  15:11 | 10:37p  04:43a |      Set  03:48a   83%|
|Wed 27| 06:03a  09:17p  15:13 | 10:38p  04:42a |      Set  04:08a   90%|
|Thu 28| 06:02a  09:17p  15:15 | 10:40p  04:41a |      Set  04:32a   95%|
|Fri 29| 06:02a  09:18p  15:16 | 10:41p  04:40a |      Set  05:01a   98%|
|Sat 30| 06:01a  09:19p  15:18 | 10:42p  04:39a |      Set  05:37a  100%|
+------+-----------------------+----------------+-----------------------+
|Sun 31| 06:00a  09:20p  15:19 | 10:43p  04:38a |Full  Rise 10:19p   99%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise

Created using my LookingUp for DOS app.