Archive
05/01/2018 – Ephemeris – Previewing May Skies
Ephemeris for Tuesday, the first day of May. The Sun rises at 6:32. It’ll be up for 14 hours and 15 minutes, setting at 8:47. The Moon, 2 days past full, will rise at 10:32 this evening.
They say April showers bring May flowers, but I don’t think they meant snow showers. Daylight hours in the Interlochen/Traverse City area will increase from 14 hours and 15 minutes today to 15 hours 19 minutes on May 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 your 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 about 3 a.m. this Saturday morning the 5th, but the bright morning Moon will interfere.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
May Evening Sky Chart

Star Chart for May 2018 (11 p.m. EDT May 15, 2018). Created using my LookingUp program. Click on image to enlarge.
The planets and stars are plotted for the 15th at 11 p.m. EDT in the evening and 5 a.m. 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 and 45 minutes behind our daylight standard time meridian. during EST). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes (Daylight Time) or 45 minutes (Standard Time) earlier than the current time.
Note the chart times of 11 p.m. and 5 a.m. are for the 15th. For each week before the 15th add ½ hour (28 minutes if you’re picky). For each week after the 15th subtract ½ hour. 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.
May Morning Star Chart

Star Chart for May 2018 mornings based on 5 a.m. May 15th. Created using my LookingUp program. Click on image to enlarge.
For a list of constellation names to go with the abbreviations click here.
Star chart annotations
- Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
- Leaky Big Dipper drips on Leo.
- Follow the arc of the handle of the Big Dipper to the star Arcturus and
- Continue with a spike to Spica.
- The Summer Triangle is in red.
- EAqr is the Eta Aquariid meteor shower radiant. This shower will be plagued by a waning gibbous moon. It will be addressed in the May 3rd program. This is a shower of bits from Halley’s Comet.
Twilight
Evening nautical twilight ends at 10:02 p.m. EDT on the 1st, increasing to 10:44 p.m. EDT on the 31st.
Evening astronomical twilight ends at 10:46 p.m. EDT on the 1st, increasing to 11:42 p.m. EDT on the 31st.
Morning astronomical twilight starts at 4:40 a.m. EDT on the 1st, and decreasing to 3:45 a.m. EDT on the 31st.
Morning nautical twilight starts at 5:25 a.m. EDT on the 1st, and decreasing to 4:44 a.m. EDT on the 31st.
NASA Calendar of Planetary Events
Date Time Event
May 01 Tu Venus: 27.2° E
02 We 9:24 am Venus-Aldebaran: 6.4° N
04 Fr 4:31 pm Moon-Saturn: 1.9° S
04 Fr 7:00 pm Moon South Dec.: 20.6° S
05 Sa 3:03 am Eta Aquarid Shower: ZHR = 60
05 Sa 8:35 pm Moon Apogee: 404500 km
06 Su 3:24 am Moon-Mars: 3° S
07 Mo 6:24 am Moon Descending Node
07 Mo 10:09 pm Last Quarter
08 Tu 8:10 pm Jupiter Opposition
13 Su 1:21 pm Moon-Mercury: 2.5° N
15 Tu 7:48 am New Moon
17 Th 2:11 pm Moon-Venus: 4.8° N
17 Th 5:06 pm Moon Perigee: 363800 km
18 Fr 11:02 am Moon North Dec.: 20.7° N
20 Su 7:57 am Moon-Beehive: 1.7° N
20 Su 9:13 am Moon Ascending Node
21 Mo 8:53 pm Moon-Regulus: 1.5° S
21 Mo 11:49 pm First Quarter
27 Su 1:39 pm Moon-Jupiter: 4.3° S
29 Tu 10:20 am Full Moon
31 Th 9:20 pm Moon-Saturn: 1.8° S
Jun 01 Fr Venus: 34.5° E
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
May, 2018 Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM |
| | RISE SET HOURS | END START |PHASE SET** TIME FRACTN|
+=======================================================================+
|Tue 1| 06:32a 08:47p 14:15 | 10:00p 05:20a | Rise 10:32p 96%|
|Wed 2| 06:31a 08:49p 14:17 | 10:01p 05:18a | Rise 11:31p 91%|
|Thu 3| 06:29a 08:50p 14:20 | 10:03p 05:17a | Rise 12:26a 85%|
|Fri 4| 06:28a 08:51p 14:23 | 10:04p 05:15a | Rise 01:15a 78%|
|Sat 5| 06:27a 08:52p 14:25 | 10:06p 05:13a | Rise 02:00a 69%|
+------+-----------------------+----------------+-----------------------+
|Sun 6| 06:25a 08:53p 14:28 | 10:07p 05:12a | Rise 02:39a 60%|
|Mon 7| 06:24a 08:55p 14:30 | 10:09p 05:10a |L Qtr Rise 03:14a 51%|
|Tue 8| 06:23a 08:56p 14:33 | 10:11p 05:08a | Rise 03:45a 41%|
|Wed 9| 06:21a 08:57p 14:35 | 10:12p 05:06a | Rise 04:14a 32%|
|Thu 10| 06:20a 08:58p 14:38 | 10:14p 05:05a | Rise 04:42a 23%|
|Fri 11| 06:19a 08:59p 14:40 | 10:15p 05:03a | Rise 05:09a 15%|
|Sat 12| 06:18a 09:00p 14:42 | 10:17p 05:02a | Rise 05:38a 8%|
+------+-----------------------+----------------+-----------------------+
|Sun 13| 06:16a 09:02p 14:45 | 10:18p 05:00a | Rise 06:09a 3%|
|Mon 14| 06:15a 09:03p 14:47 | 10:20p 04:59a | Rise 06:45a 1%|
|Tue 15| 06:14a 09:04p 14:49 | 10:21p 04:57a |New Set 09:20p 1%|
|Wed 16| 06:13a 09:05p 14:52 | 10:23p 04:56a | Set 10:32p 3%|
|Thu 17| 06:12a 09:06p 14:54 | 10:24p 04:54a | Set 11:40p 9%|
|Fri 18| 06:11a 09:07p 14:56 | 10:26p 04:53a | Set 12:41a 17%|
|Sat 19| 06:10a 09:08p 14:58 | 10:27p 04:51a | Set 01:33a 26%|
+------+-----------------------+----------------+-----------------------+
|Sun 20| 06:09a 09:09p 15:00 | 10:29p 04:50a | Set 02:17a 37%|
|Mon 21| 06:08a 09:10p 15:02 | 10:30p 04:49a |F Qtr Set 02:55a 48%|
|Tue 22| 06:07a 09:12p 15:04 | 10:32p 04:47a | Set 03:27a 59%|
|Wed 23| 06:06a 09:13p 15:06 | 10:33p 04:46a | Set 03:56a 70%|
|Thu 24| 06:05a 09:14p 15:08 | 10:34p 04:45a | Set 04:24a 79%|
|Fri 25| 06:05a 09:15p 15:09 | 10:36p 04:44a | Set 04:52a 87%|
|Sat 26| 06:04a 09:16p 15:11 | 10:37p 04:43a | Set 05:20a 93%|
+------+-----------------------+----------------+-----------------------+
|Sun 27| 06:03a 09:16p 15:13 | 10:38p 04:42a | Set 05:51a 97%|
|Mon 28| 06:02a 09:17p 15:15 | 10:39p 04:41a | Set 06:24a 99%|
|Tue 29| 06:02a 09:18p 15:16 | 10:41p 04:40a |Full Rise 09:21p 100%|
|Wed 30| 06:01a 09:19p 15:18 | 10:42p 04:39a | Rise 10:18p 98%|
|Thu 31| 06:00a 09:20p 15:19 | 10:43p 04:38a | Rise 11:10p 95%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise