Bob Moler's Ephemeris Blog

Ephemeris for Tuesday, July 31st. The Sun rises at 6:27. It’ll be up for 14 hours and 41 minutes, setting at 9:09. The Moon, half way from full to last quarter, will rise at 11:17 this evening.

Let’s look ahead at the month of August in the skies. Daylight hours will decrease from 14 hours and 39 minutes tomorrow to 13 hours 17 minutes on the 31st. The altitude of the sun at local noon, that is degrees of angle above the horizon will decrease from 63 degrees tomorrow to just over 53 degrees on the 31st. Straits area listeners can subtract one more degree from those angles. Local noon, when the Sun is due south, is about 1:43 p.m. The Perseid meteor shower will reach its peak all night on the 12th. It will be a dark night with the one day old moon setting at 10 p.m. The radiant point, where the meteors will seem to come from, will be rising higher in the northeastern sky all night. On the 17th Venus will reach ts greatest separation from the Sun in the evening sky.

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

Addendum

August Evening Star Chart

Star Chart for August 2018 (10 p.m. EDT August 15, 2018). 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 4:30 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). 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 10 p.m. and 4:30 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.

August Morning Star Chart

Star Chart for August 2018 mornings based on 4:30 a.m. August 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 and
• Continue with a spike to Spica.
• The Summer Triangle is in red.
• PerR – Perseid meteor shower radiant

Twilight

Twilight calendar was generated in Cartes du Ciel.

NASA Calendar of Planetary Events

Date        Time    Event
Aug 01  We          Venus: 45.1° E
    04  Sa  2:18 pm Last Quarter
    06  Mo  2:35 pm Moon-Aldebaran: 1.1° S
    08  We  6:33 pm Moon North Dec.: 20.8° N
    08  We  9:59 pm Mercury Inferior Conj.
    10  Fr  9:40 am Moon Ascending Node
    10  Fr  2:05 pm Moon Perigee: 358100 km
    11  Sa  5:47 am Partial Solar Eclipse (NE Canada to Asia)
    11  Sa  5:58 am New Moon
    12  Su  8:44 pm Perseid Meteor Shower: ZHR = 90
    14  Tu  9:35 am Moon-Venus: 6.4° S
    17  Fr  6:38 am Moon-Jupiter: 4.8° S
    17  Fr 11:59 am Venus Greatest Elongation: 45.9° E
    18  Sa  3:49 am First Quarter
    20  Mo 10:07 pm Mercury-Beehive: 5.9° S
    21  Tu  5:55 am Moon-Saturn: 2.4° S
    21  Tu 10:58 pm Moon South Dec.: 20.8° S
    23  Th  7:23 am Moon Apogee: 405700 km
    24  Fr 12:51 am Moon Descending Node
    26  Su  7:56 am Full Moon
    26  Su  3:59 pm Mercury Greatest Elongation: 18.3° W
Sep 01  Sa          Venus: 45° 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
     August, 2018    Local time zone: EDT
     +-----------------------------------------------------------------------+
     | DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
     |      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
     +=======================================================================+
     |Wed  1| 06:29a  09:08p  14:39 | 10:23p  05:13a |      Rise 11:43p   77%|
     |Thu  2| 06:30a  09:07p  14:37 | 10:22p  05:14a |      Rise 12:09a   68%|
     |Fri  3| 06:31a  09:05p  14:34 | 10:20p  05:16a |      Rise 12:37a   58%|
     |Sat  4| 06:32a  09:04p  14:32 | 10:18p  05:17a |L Qtr Rise 01:08a   47%|
     +------+-----------------------+----------------+-----------------------+
     |Sun  5| 06:33a  09:03p  14:29 | 10:17p  05:19a |      Rise 01:44a   37%|
     |Mon  6| 06:34a  09:01p  14:27 | 10:15p  05:20a |      Rise 02:27a   26%|
     |Tue  7| 06:35a  09:00p  14:24 | 10:13p  05:22a |      Rise 03:18a   17%|
     |Wed  8| 06:37a  08:59p  14:22 | 10:11p  05:23a |      Rise 04:20a    9%|
     |Thu  9| 06:38a  08:57p  14:19 | 10:10p  05:25a |      Rise 05:30a    3%|
     |Fri 10| 06:39a  08:56p  14:16 | 10:08p  05:26a |      Rise 06:45a    0%|
     |Sat 11| 06:40a  08:54p  14:14 | 10:06p  05:28a |New   Set  09:21p    1%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 12| 06:41a  08:53p  14:11 | 10:04p  05:29a |      Set  09:58p    4%|
     |Mon 13| 06:42a  08:51p  14:08 | 10:02p  05:31a |      Set  10:30p   10%|
     |Tue 14| 06:44a  08:50p  14:06 | 10:00p  05:32a |      Set  11:00p   17%|
     |Wed 15| 06:45a  08:48p  14:03 | 09:59p  05:34a |      Set  11:29p   27%|
     |Thu 16| 06:46a  08:46p  14:00 | 09:57p  05:35a |      Set  11:59p   36%|
     |Fri 17| 06:47a  08:45p  13:57 | 09:55p  05:37a |      Set  12:29a   47%|
     |Sat 18| 06:48a  08:43p  13:54 | 09:53p  05:38a |F Qtr Set  01:03a   57%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 19| 06:49a  08:42p  13:52 | 09:51p  05:40a |      Set  01:40a   66%|
     |Mon 20| 06:51a  08:40p  13:49 | 09:49p  05:41a |      Set  02:22a   75%|
     |Tue 21| 06:52a  08:38p  13:46 | 09:47p  05:43a |      Set  03:09a   83%|
     |Wed 22| 06:53a  08:37p  13:43 | 09:45p  05:44a |      Set  04:00a   89%|
     |Thu 23| 06:54a  08:35p  13:40 | 09:43p  05:46a |      Set  04:56a   94%|
     |Fri 24| 06:55a  08:33p  13:37 | 09:41p  05:47a |      Set  05:54a   98%|
     |Sat 25| 06:56a  08:31p  13:34 | 09:39p  05:48a |      Set  06:54a  100%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 26| 06:58a  08:30p  13:31 | 09:37p  05:50a |Full  Rise 08:54p  100%|
     |Mon 27| 06:59a  08:28p  13:29 | 09:35p  05:51a |      Rise 09:21p   98%|
     |Tue 28| 07:00a  08:26p  13:26 | 09:33p  05:53a |      Rise 09:47p   94%|
     |Wed 29| 07:01a  08:24p  13:23 | 09:31p  05:54a |      Rise 10:13p   88%|
     |Thu 30| 07:02a  08:23p  13:20 | 09:29p  05:56a |      Rise 10:40p   81%|
     |Fri 31| 07:04a  08:21p  13:17 | 09:27p  05:57a |      Rise 11:09p   72%|
     +-----------------------------------------------------------------------+
     * Nautical Twilight
     ** Moon rise or moon set, whichever occurs between sunrise and sunset

Ephemeris of Sky Events is created with my DOS version LookingUp program.