Bob Moler's Ephemeris Blog

Ephemeris for Thursday, November 30th. The Sun will rise at 7:58. It’ll be up for 9 hours and 5 minutes, setting at 5:03. The Moon, 3 days before full, will set at 5:07 tomorrow morning.

Tomorrow starts the last month of the 2017. We are now in the holiday season and about to celebrate the southernmost travel of the Sun in the sky and its return northward. The Sun will stop its travel south, the winter solstice on the 21st at 11:29 a.m. That will make that day the shortest day in terms of daylight hours. However the earliest sunset and latest sunrise don’t coincide with that date. The reason is the Earth is closer to the sun than average and moving faster in its orbit of the sun than it normally does. It skews the sunrise and sunset times, making them later than they would be on average. That makes the sunset times bottom out about December 9th. at 5:02 p.m. And that latest sunrise will top out on January 2nd at 8:20 a.m.

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

Addenda

December Evening Sky Chart

Star Chart for December 2017 (9 p.m. December 15, 2017). Created using my LookingUp program. Click on image to enlarge.

The planets and stars are plotted for the 15th at 9 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 9 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. For planet positions on dates other than the 15th, check the Wednesday planet posts on this blog.

December Morning Star Chart

Star Chart for December 2017 mornings based on 6 a.m. December 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.
• Follow the arc of the handle of the Big Dipper to the star Arcturus.
• The Summer Triangle is in red
• GemR is the Geminid meteor shower radiant. Peaks on December 14th, the Moon will not interfere this year.

Twilight

Evening nautical twilight ends at 6:16 p.m. EST on the 1st, decreasing to 6:21 p.m. EDT on the 31st.
Evening astronomical twilight ends at 6:51 p.m. EST on the 1st, decreasing to 6:56 p.m. EDT on the 31st.
Morning astronomical twilight starts at 6:20 a.m. EST on the 1st, and increasing to 6:35 a.m. EDT on the 31st.
Morning nautical twilight starts at 6:56 a.m. EST on the 1st, and increasing to 7:10 a.m. EDT on the 31st.

NASA Calendar of Planetary Events

  Date      Time    Event
Dec 01  Fr          Venus: 9.4° W
    03  Su  8:00 am Moon-Aldebaran: 0.8° S
    03  Su 10:47 am Full Moon
    04  Mo  3:42 am Moon Perigee: 357500 km
    05  Tu  6:43 am Moon North Dec.: 20° N
    07  Th  4:30 am Moon-Beehive: 2.5° N
    07  Th  7:39 pm Moon Ascending Node
    08  Fr  5:25 pm Moon-Regulus: 0.7° S
    10  Su  2:51 am Last Quarter
    12  Tu  8:40 pm Mercury Inferior Conjunction with the Sun
    13  We 11:27 am Moon-Mars: 4.5° S
    14  Th  1:07 am Geminid Meteor Shower: ZHR = 120!
    14  Th  9:26 am Moon-Jupiter: 4.7° S
    18  Mo  1:31 am New Moon
    18  Mo  8:27 am Moon Apogee: 406600 km
    19  Tu  4:31 am Moon South Dec.: 20.1° S
    21  Th 11:29 am Winter Solstice
    21  Th  3:18 pm Saturn Conjunction with the Sun
    22  Fr  5:04 am Moon Descending Node
    22  Fr 10:00 am Ursid Meteor Shower: ZHR = 10
                    Note:  The Ursid radiant is near the Little Dipper’s
                           bowl
    26  Tu  4:20 am First Quarter
    30  Sa  7:25 pm Moon-Aldebaran: 0.7° S
Jan 01  Mo          Venus: 1.9° 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 an entire year
or calendar pages for your time zone.

Sun and Moon Rising and Setting Events

     LU                  Ephemeris of Sky Events for Interlochen/TC
December, 2017    Local time zone: EST
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Fri  1| 08:00a  05:03p  09:03 | 06:12p  06:50a |      Set  06:22a   96%|
|Sat  2| 08:01a  05:03p  09:01 | 06:12p  06:51a |      Set  07:38a   99%|
+------+-----------------------+----------------+-----------------------+
|Sun  3| 08:02a  05:02p  09:00 | 06:12p  06:52a |Full  Rise 05:36p  100%|
|Mon  4| 08:03a  05:02p  08:59 | 06:12p  06:53a |      Rise 06:32p   97%|
|Tue  5| 08:04a  05:02p  08:57 | 06:12p  06:54a |      Rise 07:35p   92%|
|Wed  6| 08:05a  05:02p  08:56 | 06:12p  06:55a |      Rise 08:43p   84%|
|Thu  7| 08:06a  05:02p  08:55 | 06:12p  06:56a |      Rise 09:54p   75%|
|Fri  8| 08:07a  05:02p  08:54 | 06:12p  06:57a |      Rise 11:04p   64%|
|Sat  9| 08:08a  05:02p  08:53 | 06:12p  06:58a |      Rise 12:13a   54%|
+------+-----------------------+----------------+-----------------------+
|Sun 10| 08:09a  05:02p  08:52 | 06:12p  06:59a |L Qtr Rise 01:19a   43%|
|Mon 11| 08:10a  05:02p  08:51 | 06:12p  06:59a |      Rise 02:23a   33%|
|Tue 12| 08:11a  05:02p  08:51 | 06:12p  07:00a |      Rise 03:25a   24%|
|Wed 13| 08:11a  05:02p  08:50 | 06:12p  07:01a |      Rise 04:27a   16%|
|Thu 14| 08:12a  05:02p  08:49 | 06:13p  07:02a |      Rise 05:27a   10%|
|Fri 15| 08:13a  05:02p  08:49 | 06:13p  07:02a |      Rise 06:26a    5%|
|Sat 16| 08:14a  05:03p  08:49 | 06:13p  07:03a |      Rise 07:22a    2%|
+------+-----------------------+----------------+-----------------------+
|Sun 17| 08:14a  05:03p  08:48 | 06:14p  07:04a |      Rise 08:16a    0%|
|Mon 18| 08:15a  05:03p  08:48 | 06:14p  07:04a |New   Set  05:46p    1%|
|Tue 19| 08:16a  05:04p  08:48 | 06:14p  07:05a |      Set  06:34p    3%|
|Wed 20| 08:16a  05:04p  08:48 | 06:15p  07:05a |      Set  07:27p    6%|
|Thu 21| 08:17a  05:05p  08:48 | 06:15p  07:06a |      Set  08:23p   12%|
|Fri 22| 08:17a  05:05p  08:48 | 06:16p  07:06a |      Set  09:22p   19%|
|Sat 23| 08:18a  05:06p  08:48 | 06:16p  07:07a |      Set  10:22p   27%|
+------+-----------------------+----------------+-----------------------+
|Sun 24| 08:18a  05:06p  08:48 | 06:17p  07:07a |      Set  11:24p   36%|
|Mon 25| 08:18a  05:07p  08:48 | 06:18p  07:08a |      Set  12:28a   46%|
|Tue 26| 08:19a  05:08p  08:49 | 06:18p  07:08a |F Qtr Set  01:35a   56%|
|Wed 27| 08:19a  05:08p  08:49 | 06:19p  07:08a |      Set  02:43a   67%|
|Thu 28| 08:19a  05:09p  08:50 | 06:20p  07:09a |      Set  03:55a   77%|
|Fri 29| 08:19a  05:10p  08:50 | 06:20p  07:09a |      Set  05:08a   86%|
|Sat 30| 08:19a  05:11p  08:51 | 06:21p  07:09a |      Set  06:22a   93%|
+------+-----------------------+----------------+-----------------------+
|Sun 31| 08:20a  05:12p  08:52 | 06:22p  07:09a |      Set  07:32a   98%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise