Bob Moler's Ephemeris Blog

This is Ephemeris for Tuesday, September 1st. Today the Sun will be up for 13 hours and 12 minutes, setting at 8:18, and it will rise tomorrow at 7:07. The Moon, 1 day before full, will set at 7:15 tomorrow morning.

Let’s look at the skies for September. Daylight hours in the Interlochen/Traverse City area and will drop from 13 hours and 12 minutes today to 11 hours 43 minutes on the 30th. The altitude of the sun above the southern horizon at local noon will be 53 degrees today, and will descend to 42 degrees on the 30th. The official season of summer is getting short too, so enjoy it while you can. Summer will end and autumn will begin at 9:31 a.m. on the 22nd as the Sun will pass overhead at the equator heading southward. It will also mark sunset at the north pole and sunrise at the south pole. Southern hemisphere dwellers will see the start of spring. The summer Milky way is still visible to explore with binoculars or telescope.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

September Star Chart

Star Chart for September 2020. Created using my LookingUp program. Click on the image to enlarge. Created using my LookingUp program.

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, 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.

September Morning Star Chart

Star Chart for September 2020 (10 p.m. EDT September 15, 2019). Click on image to enlarge.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 dipper drips on Leo.
• Follow the arc of the handle of the Big Dipper to the star Arcturus.
• The Summer Triangle is in red.

Twilight Limits, Nautical and Astronomical

			EDT
	Morning twilight		Evening twilight		Dark night		Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2020-09-01	5h26m	6h05m	21h28m	22h06m	–	–	0.99
2020-09-02	5h28m	6h06m	21h26m	22h04m	–	–	1
2020-09-03	5h30m	6h07m	21h24m	22h01m	–	–	0.99
2020-09-04	5h31m	6h09m	21h22m	21h59m	–	–	0.96
2020-09-05	5h33m	6h10m	21h20m	21h57m	21h57m	22h01m	0.91
2020-09-06	5h34m	6h11m	21h18m	21h55m	21h55m	22h22m	0.85
2020-09-07	5h36m	6h13m	21h16m	21h53m	21h53m	22h46m	0.77
2020-09-08	5h37m	6h14m	21h13m	21h50m	21h50m	23h14m	0.69
2020-09-09	5h39m	6h15m	21h11m	21h48m	21h48m	23h47m	0.59
2020-09-10	5h40m	6h17m	21h09m	21h46m	21h46m	–	0.49
2020-09-11	5h42m	6h18m	21h07m	21h44m	21h44m	0h28m	0.39
2020-09-12	5h43m	6h19m	21h05m	21h42m	21h42m	1h19m	0.29
2020-09-13	5h45m	6h21m	21h03m	21h39m	21h39m	2h19m	0.19
2020-09-14	5h46m	6h22m	21h01m	21h37m	21h37m	3h27m	0.11
2020-09-15	5h47m	6h23m	20h59m	21h35m	21h35m	4h42m	0.05
2020-09-16	5h49m	6h24m	20h57m	21h33m	21h33m	5h49m	0.01
2020-09-17	5h50m	6h26m	20h55m	21h31m	21h31m	5h50m	0
2020-09-18	5h52m	6h27m	20h53m	21h29m	21h29m	5h52m	0.03
2020-09-19	5h53m	6h28m	20h51m	21h27m	21h27m	5h53m	0.08
2020-09-20	5h54m	6h30m	20h49m	21h25m	21h50m	5h54m	0.16
2020-09-21	5h56m	6h31m	20h47m	21h23m	22h25m	5h56m	0.26
2020-09-22	5h57m	6h32m	20h46m	21h20m	23h05m	5h57m	0.38
2020-09-23	5h59m	6h33m	20h44m	21h18m	23h54m	5h59m	0.49
2020-09-24	6h00m	6h35m	20h42m	21h16m	–	6h00m	0.6
2020-09-25	6h01m	6h36m	20h40m	21h14m	0h49m	6h01m	0.71
2020-09-26	6h03m	6h37m	20h38m	21h12m	1h51m	6h03m	0.8
2020-09-27	6h04m	6h38m	20h36m	21h10m	2h55m	6h04m	0.87
2020-09-28	6h05m	6h40m	20h34m	21h08m	4h01m	6h05m	0.93
2020-09-29	6h06m	6h41m	20h32m	21h06m	5h06m	6h06m	0.93
2020-09-30	6h08m	6h42m	20h30m	21h04m	–	–	0.97

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/2018/09/27/.

NASA Calendar of Planetary Events

      Date   Time    Event
Sep 1  Tu            Venus: 44.7° W
    2  We  01:22 am  Full Moon
    6  Su  12:42 am  Moon-Mars: 0°
    6  Su  02:31 am  Moon Apogee: 405,600 km
   10  Th  05:26 am  Last Quarter
   10  Th  07:05 pm  Moon Ascending Node
   11  Fr  03:15 pm  Neptune Opposition
   12  Sa  01:25 am  Moon North Dec.: 24.4° N
   12  Sa  08:10 pm  Venus-Beehive: 2.6° S
   13  Su  11:19 pm  Moon-Beehive: 1.9° S
   14  Mo  12:43 am  Moon-Venus: 4.6° S
   17  Th  07:00 am  New Moon
   18  Fr  09:44 am  Moon Perigee: 359,100 km
   22  Tu  02:06 am  Mercury-Spica: 0.3° N
   22  Tu  09:31 am  Autumnal Equinox
   23  We  08:33 am  Moon Descending Node
   23  We  09:55 pm  First Quarter
   24  Th  03:11 pm  Moon South Dec.: 24.5° S
   25  Fr  02:46 am  Moon-Jupiter: 1.7° N
   25  Fr  04:46 pm  Moon-Saturn: 2.5° N
Oct 1  Th            Venus: 40.3° W

All event times are given for UTC-4 hr: Eastern Daylight Saving 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
September, 2020    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Tue  1| 07:05a  08:18p  13:12 | 09:24p  05:59a |      Set  07:15a  100%|
|Wed  2| 07:07a  08:16p  13:09 | 09:22p  06:00a |Full  Rise 08:58p   99%|
|Thu  3| 07:08a  08:14p  13:06 | 09:20p  06:02a |      Rise 09:20p   97%|
|Fri  4| 07:09a  08:13p  13:03 | 09:18p  06:03a |      Rise 09:40p   93%|
|Sat  5| 07:10a  08:11p  13:00 | 09:16p  06:04a |      Rise 10:00p   87%|
+------+-----------------------+----------------+-----------------------+
|Sun  6| 07:11a  08:09p  12:57 | 09:14p  06:06a |      Rise 10:22p   80%|
|Mon  7| 07:12a  08:07p  12:54 | 09:12p  06:07a |      Rise 10:46p   72%|
|Tue  8| 07:14a  08:05p  12:51 | 09:10p  06:09a |      Rise 11:14p   63%|
|Wed  9| 07:15a  08:03p  12:48 | 09:08p  06:10a |      Rise 11:48p   54%|
|Thu 10| 07:16a  08:01p  12:45 | 09:06p  06:11a |L Qtr Rise 12:29a   44%|
|Fri 11| 07:17a  07:59p  12:42 | 09:04p  06:12a |      Rise 01:19a   34%|
|Sat 12| 07:18a  07:58p  12:39 | 09:02p  06:14a |      Rise 02:19a   25%|
+------+-----------------------+----------------+-----------------------+
|Sun 13| 07:19a  07:56p  12:36 | 09:00p  06:15a |      Rise 03:27a   16%|
|Mon 14| 07:21a  07:54p  12:33 | 08:58p  06:16a |      Rise 04:42a    9%|
|Tue 15| 07:22a  07:52p  12:30 | 08:56p  06:18a |      Rise 06:01a    3%|
|Wed 16| 07:23a  07:50p  12:27 | 08:54p  06:19a |      Rise 07:20a    1%|
|Thu 17| 07:24a  07:48p  12:24 | 08:52p  06:20a |New   Set  08:25p    1%|
|Fri 18| 07:25a  07:46p  12:20 | 08:50p  06:22a |      Set  08:52p    4%|
|Sat 19| 07:27a  07:44p  12:17 | 08:48p  06:23a |      Set  09:19p   10%|
+------+-----------------------+----------------+-----------------------+
|Sun 20| 07:28a  07:42p  12:14 | 08:46p  06:24a |      Set  09:50p   18%|
|Mon 21| 07:29a  07:41p  12:11 | 08:44p  06:25a |      Set  10:24p   27%|
|Tue 22| 07:30a  07:39p  12:08 | 08:42p  06:27a |      Set  11:05p   38%|
|Wed 23| 07:31a  07:37p  12:05 | 08:40p  06:28a |F Qtr Set  11:53p   49%|
|Thu 24| 07:32a  07:35p  12:02 | 08:38p  06:29a |      Set  12:49a   60%|
|Fri 25| 07:34a  07:33p  11:59 | 08:36p  06:30a |      Set  01:51a   70%|
|Sat 26| 07:35a  07:31p  11:56 | 08:34p  06:32a |      Set  02:55a   79%|
+------+-----------------------+----------------+-----------------------+
|Sun 27| 07:36a  07:29p  11:53 | 08:32p  06:33a |      Set  04:01a   86%|
|Mon 28| 07:37a  07:27p  11:50 | 08:30p  06:34a |      Set  05:06a   92%|
|Tue 29| 07:38a  07:26p  11:47 | 08:28p  06:35a |      Set  06:09a   97%|
|Wed 30| 07:40a  07:24p  11:43 | 08:27p  06:37a |      Set  07:11a   99%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.