Bob Moler's Ephemeris Blog

This is Ephemeris for Thursday, May 1st. Today the Sun will be up for 14 hours and 15 minutes, setting at 8:48, and it will rise tomorrow at 6:30. The Moon, 3 days before first quarter, will set at 2:05 tomorrow morning.

May is here, when the promise made on Groundhog Day is finally fulfilled. Daylight hours in the Interlochen/Traverse City area will increase from 14 hours and 15 minutes today to 15 hours 20 minutes on the 31st. The altitude, or angle, of the Sun above the southern horizon at local noon will ascend from 61 degrees now to 67 degrees at month’s end. The altitude of the Sun in the Straits area will be a degree lower than that, but your daylight hours will be a few minutes longer. Local apparent noon this month, when the Sun passes due south, will be about 1:38 p.m. This is the month of the Eta Aquariid meteor shower which will reach its peak next week Tuesday morning. There will be less than an hour of prime viewing after the Moon sets at 4:03 AM.

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 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 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

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, and
• Extend like a spike to Spica,
• EaqR is the radiant of the Eta Aquariid meteor shower that peaks on the 5th.

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.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

   Date       Time    Event
May  1  Th            Venus: 40.9° W
     1  Th   2:35 AM  Moon North Dec.: 28.6° N
     2  Fr   8:02 PM  Moon-Pollux: 2.2° N
     3  Sa   7:12 PM  Moon-Mars: 2.2° S
     3  Sa   7:27 PM  Moon-Beehive: 2.6° S
     4  Su   7:59 AM  Mars-Beehive: 0.4° N
     4  Su   9:52 AM  First Quarter
     4  Su  10:07 PM  Eta Aquariid Shower: ZHR = 60
     5  Mo   1:58 PM  Moon-Regulus: 2.2° S
     7  We   7:44 PM  Moon Descending Node
    10  Sa   3:43 AM  Moon-Spica: 0.4° N
    10  Sa   8:49 PM  Moon Apogee: 406200 km
    12  Mo  12:56 PM  Full Moon
    14  We  12:10 AM  Moon-Antares: 0.3° N
    15  Th   2:44 PM  Moon South Dec.: 28.5° S
    17  Sa   8:55 PM  Uranus Conjunction
    20  Tu   7:59 AM  Last Quarter
    22  Th   4:05 AM  Moon Ascending Node
    22  Th   1:51 PM  Moon-Saturn: 2.8° S
    23  Fr   7:52 PM  Moon-Venus: 4° S
    25  Su   9:37 PM  Moon Perigee: 359000 km
    26  Mo  11:02 PM  New Moon
    28  We  12:16 PM  Moon North Dec.: 28.4° N
    30  Fr  12:07 AM  Mercury Superior Conjunction
    30  Fr   5:13 AM  Moon-Pollux: 2.4° N
    31  Sa   4:00 AM  Moon-Beehive: 2.3° S
    31  Sa   9:59 PM  Venus Elongation: 45.9° W
Jun  1  Su            Venus: 45.9° W

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, 2025    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Thu  1| 06:32a  08:48p  14:15 | 10:00p  05:20a |      Set  02:05a   24%|
|Fri  2| 06:30a  08:49p  14:18 | 10:02p  05:18a |      Set  02:47a   34%|
|Sat  3| 06:29a  08:50p  14:21 | 10:03p  05:16a |      Set  03:19a   44%|
+------+-----------------------+----------------+-----------------------+
|Sun  4| 06:28a  08:51p  14:23 | 10:05p  05:14a |F Qtr Set  03:43a   54%|
|Mon  5| 06:26a  08:53p  14:26 | 10:06p  05:13a |      Set  04:03a   64%|
|Tue  6| 06:25a  08:54p  14:28 | 10:08p  05:11a |      Set  04:20a   73%|
|Wed  7| 06:23a  08:55p  14:31 | 10:10p  05:09a |      Set  04:36a   81%|
|Thu  8| 06:22a  08:56p  14:33 | 10:11p  05:08a |      Set  04:51a   88%|
|Fri  9| 06:21a  08:57p  14:36 | 10:13p  05:06a |      Set  05:08a   94%|
|Sat 10| 06:20a  08:59p  14:38 | 10:14p  05:04a |      Set  05:27a   97%|
+------+-----------------------+----------------+-----------------------+
|Sun 11| 06:18a  09:00p  14:41 | 10:16p  05:03a |      Set  05:50a   99%|
|Mon 12| 06:17a  09:01p  14:43 | 10:17p  05:01a |Full  Rise 09:34p  100%|
|Tue 13| 06:16a  09:02p  14:45 | 10:19p  05:00a |      Rise 10:39p   98%|
|Wed 14| 06:15a  09:03p  14:48 | 10:20p  04:58a |      Rise 11:41p   95%|
|Thu 15| 06:14a  09:04p  14:50 | 10:22p  04:57a |      Rise 12:36a   90%|
|Fri 16| 06:13a  09:05p  14:52 | 10:23p  04:55a |      Rise 01:21a   83%|
|Sat 17| 06:12a  09:06p  14:54 | 10:25p  04:54a |      Rise 01:57a   75%|
+------+-----------------------+----------------+-----------------------+
|Sun 18| 06:11a  09:08p  14:57 | 10:26p  04:52a |      Rise 02:27a   66%|
|Mon 19| 06:10a  09:09p  14:59 | 10:28p  04:51a |      Rise 02:51a   55%|
|Tue 20| 06:09a  09:10p  15:01 | 10:29p  04:50a |L Qtr Rise 03:12a   45%|
|Wed 21| 06:08a  09:11p  15:03 | 10:31p  04:48a |      Rise 03:32a   34%|
|Thu 22| 06:07a  09:12p  15:05 | 10:32p  04:47a |      Rise 03:51a   23%|
|Fri 23| 06:06a  09:13p  15:06 | 10:33p  04:46a |      Rise 04:13a   14%|
|Sat 24| 06:05a  09:14p  15:08 | 10:35p  04:45a |      Rise 04:39a    7%|
+------+-----------------------+----------------+-----------------------+
|Sun 25| 06:04a  09:15p  15:10 | 10:36p  04:44a |      Rise 05:12a    2%|
|Mon 26| 06:04a  09:16p  15:12 | 10:37p  04:42a |New   Set  09:25p    0%|
|Tue 27| 06:03a  09:17p  15:13 | 10:39p  04:41a |      Set  10:44p    1%|
|Wed 28| 06:02a  09:18p  15:15 | 10:40p  04:40a |      Set  11:50p    5%|
|Thu 29| 06:01a  09:19p  15:17 | 10:41p  04:39a |      Set  12:40a   11%|
|Fri 30| 06:01a  09:19p  15:18 | 10:42p  04:38a |      Set  01:17a   19%|
|Sat 31| 06:00a  09:20p  15:20 | 10:43p  04:37a |      Set  01:45a   29%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise

Created using my LookingUp for DOS app.