Archive
08/31/2017 – Ephemeris – Looking ahead at the month of September
Ephemeris for Thursday, August 31st. The Sun will rise at 7:04. It’ll be up for 13 hours and 16 minutes, setting at 8:20. The Moon, 2 days past first quarter, will set at 2:24 tomorrow morning.
Let’s look at the skies for the month of September. The sun will moving at its greatest speed in its retreat to the south. Daylight hours in the Interlochen/Traverse City area and will drop from 13 hours and 13 minutes tomorrow to 11 hours 44 minutes on the 30th. The altitude of the sun above the southern horizon at local noon will be 54 degrees tomorrow, and will descend to 42 degrees on the 30th. The season of summer is getting short, so enjoy it while you can. Summer ends and autumn begins at 4:02 p.m. on September 22nd. We are losing Jupiter in the evening sky in September, but this month, but on the 12th Mercury will be at its greatest separation from the Sun in the morning sky and relatively easy to spot.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addenda
September Evening Sky Chart

Star Chart for September 2017 (10 p.m. September 15, 2017). Created using my LookingUp program. Click on image to enlarge.
The planets and stars are plotted for the 15th at 10 p.m. EDT in the evening and 6 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 if you are near your time meridian.
Note the chart times of 10 p.m. and 6 a.m. are for the 15th. For each week before the 15th add ½ hour. For each week after the 15th subtract ½ hour. The planet positions are updated each Wednesday on this blog.
September Morning Star Chart

Star Chart for September 2017 mornings based on 6 a.m. September 15th. Created using my LookingUp program. Click on image to enlarge.
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 Big Dipper drips on Leo
- Follow the arc of the handle of the Big Dipper to the star Arcturus,
- The Summer Triangle is in red
Evening nautical twilight ends at 9:28 p.m. EDT on the 1st, decreasing to 8:31 p.m. EDT on the 30th.
Evening astronomical twilight ends at 10:06 p.m. EDT on the 1st, decreasing to 9:05 p.m. EDT on the 30th.
Morning astronomical twilight starts at 5:26 a.m. EDT on the 1st, and increasing to 6:07 a.m. EDT on the 30th.
Morning nautical twilight starts at 6:04 a.m. EDT on the 1st, and increasing to 6:42 a.m. EDT on the 30th.
NASA Calendar of Planetary Events
Sep 01 Fr Venus: 31.7° W 01 Fr 2:10 am Venus-Beehive: 1.5° S 04 Mo 2:41 pm Moon Descending Node 05 Tu 12:18 am Neptune Opposition 06 We 3:03 am Full Moon 10 Su 1:30 am Mercury-Regulus: 0.7° S 10 Su 5:39 pm Jupiter-Spica: 3.1° N 12 Tu 5:59 am Mercury Elongation: 17.9° W 12 Tu 8:09 am Moon-Aldebaran: 0.4° S 13 We 2:25 am Last Quarter 13 We 12:04 pm Moon Perigee: 369900 km 14 Th 9:00 am Moon North Dec.: 19.4° N 16 Sa 10:50 am Moon-Beehive: 3.2° N 16 Sa 2:26 pm Mercury-Mars Conjunction: 0.1° N 17 Su 2:28 pm Moon Ascending Node 17 Su 8:56 pm Moon-Venus: 0.6° N 18 Mo 12:32 am Moon-Regulus: 0.1° S 19 Tu 5:30 pm Venus-Regulus: 0.5° N 20 We 1:30 am New Moon 22 Fr 3:51 am Moon-Jupiter: 4° S 22 Fr 4:02 pm Autumnal Equinox 26 Tu 8:09 pm Moon-Saturn: 3.8° S 27 We 2:49 am Moon Apogee: 404300 km 27 We 10:54 pm First Quarter 28 Th 6:06 am Moon South Dec.: 19.5° S Oct 01 Su Venus: 24.5° W
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.
August Sun and Moon Rising and Setting Events
LU Ephemeris of Sky Events for Interlochen/TC September, 2017 Local time zone: EDT +-----------------------------------------------------------------------+ | DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM | | | RISE SET HOURS | END START |PHASE SET** TIME FRACTN| +=======================================================================+ |Fri 1| 07:05a 08:18p 13:13 | 09:25p 05:59a | Set 03:16a 82%| |Sat 2| 07:06a 08:17p 13:10 | 09:23p 06:00a | Set 04:13a 89%| +------+-----------------------+----------------+-----------------------+ |Sun 3| 07:07a 08:15p 13:07 | 09:21p 06:01a | Set 05:13a 94%| |Mon 4| 07:09a 08:13p 13:04 | 09:19p 06:03a | Set 06:17a 98%| |Tue 5| 07:10a 08:11p 13:01 | 09:17p 06:04a | Set 07:22a 100%| |Wed 6| 07:11a 08:09p 12:58 | 09:14p 06:05a |Full Rise 08:38p 99%| |Thu 7| 07:12a 08:07p 12:55 | 09:12p 06:07a | Rise 09:08p 97%| |Fri 8| 07:13a 08:06p 12:52 | 09:10p 06:08a | Rise 09:39p 91%| |Sat 9| 07:14a 08:04p 12:49 | 09:08p 06:09a | Rise 10:11p 84%| +------+-----------------------+----------------+-----------------------+ |Sun 10| 07:16a 08:02p 12:46 | 09:06p 06:11a | Rise 10:47p 75%| |Mon 11| 07:17a 08:00p 12:43 | 09:04p 06:12a | Rise 11:27p 64%| |Tue 12| 07:18a 07:58p 12:40 | 09:02p 06:13a | Rise 12:13a 53%| |Wed 13| 07:19a 07:56p 12:37 | 09:00p 06:15a |L Qtr Rise 01:05a 42%| |Thu 14| 07:20a 07:54p 12:34 | 08:58p 06:16a | Rise 02:05a 31%| |Fri 15| 07:21a 07:52p 12:30 | 08:56p 06:17a | Rise 03:10a 21%| |Sat 16| 07:23a 07:51p 12:27 | 08:54p 06:19a | Rise 04:18a 12%| +------+-----------------------+----------------+-----------------------+ |Sun 17| 07:24a 07:49p 12:24 | 08:52p 06:20a | Rise 05:27a 6%| |Mon 18| 07:25a 07:47p 12:21 | 08:50p 06:21a | Rise 06:36a 2%| |Tue 19| 07:26a 07:45p 12:18 | 08:48p 06:22a | Rise 07:43a 0%| |Wed 20| 07:27a 07:43p 12:15 | 08:46p 06:24a |New Set 08:17p 1%| |Thu 21| 07:29a 07:41p 12:12 | 08:44p 06:25a | Set 08:45p 4%| |Fri 22| 07:30a 07:39p 12:09 | 08:42p 06:26a | Set 09:14p 8%| |Sat 23| 07:31a 07:37p 12:06 | 08:41p 06:28a | Set 09:44p 15%| +------+-----------------------+----------------+-----------------------+ |Sun 24| 07:32a 07:35p 12:03 | 08:39p 06:29a | Set 10:17p 22%| |Mon 25| 07:33a 07:34p 12:00 | 08:37p 06:30a | Set 10:52p 30%| |Tue 26| 07:35a 07:32p 11:57 | 08:35p 06:31a | Set 11:32p 39%| |Wed 27| 07:36a 07:30p 11:54 | 08:33p 06:33a |F Qtr Set 12:16a 49%| |Thu 28| 07:37a 07:28p 11:50 | 08:31p 06:34a | Set 01:05a 58%| |Fri 29| 07:38a 07:26p 11:47 | 08:29p 06:35a | Set 01:59a 68%| |Sat 30| 07:39a 07:24p 11:44 | 08:27p 06:36a | Set 02:58a 76%| +-----------------------------------------------------------------------+ * Nautical Twilight ** Moonrise or moonset, whichever occurs between sunset and sunrise