Bob Moler's Ephemeris Blog

Ephemeris for Friday, June 30th. Today the Sun will be up for 15 hours and 30 minutes, setting at 9:31, and it will rise tomorrow at 6:01. The Moon, at first quarter today, will set at 1:48 tomorrow morning.

Lets preview July’s skies. The sun, having reached its northern solstice, is beginning to slide southward again, at first imperceptibly, then with greater speed. The daylight hours will decrease from 15 hours and 29 minutes tomorrow to 14 hours 40 minutes at month’s end. The daylight hours will be slightly shorter south of Interlochen, and slightly longer to the north. The altitude of the sun at local noon, when the sun is due south will decrease from 68 degrees tomorrow to 63 degrees at month’s end. The sun will be a degree lower in the Straits area. Despite the warmth, the earth will reach its greatest distance from the sun late Monday. The planet Jupiter will descend lower and lower in the west as the month progresses.

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

Addenda

July Evening Star Chart

Star Chart for July 2017 (11 p.m. July 15, 2017). 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 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 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 11 p.m. and 4:30 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.

July Morning Star Chart

Star Chart for July 2017 mornings based on 4:30 a.m. July 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,
• Then follow the Spike to Spica
• The Summer Triangle is in red
• DAqr is the Delta Aquariid Meteor Shower radiant

Evening nautical twilight ends at 11:00 p.m. EDT on the 1st, decreasing to 10:28 p.m. EDT on the 31st.
Evening astronomical twilight ends at 12:03 p.m. EDT on the 1st, decreasing to 11:17 p.m. EDT on the 31st.
Morning astronomical twilight starts at 3:41 a.m. EDT on the 1st, and increasing to 4:28 a.m. EDT on the 31st.
Morning nautical twilight starts at 4:41 a.m. EDT on the 1st, and increasing to 5:17 a.m. EDT on the 31st.

NASA Calendar of Planetary Events

Date        Time    Event
Jul 01  Sa          Venus: 43.7° W
    01  Sa  3:28 am Moon-Jupiter: 2.9° S
    03  Mo  8:59 pm Aphelion: 1.0167 AU
    04  Tu  8:21 pm Venus-Pleiades: 6.7° S
    06  Th 12:27 am Moon Apogee: 405900 km
    06  Th 11:34 pm Moon-Saturn: 3.6° S
    08  Sa  6:49 am Moon South Dec.: 19.4° S
    09  Su 12:07 am Full Moon
    09  Su  9:33 pm Mercury-Beehive: 0.1° N
    12  We  1:17 am Moon Descending Node
    13  Th  2:06 pm Venus-Aldebaran: 3.1° N
    16  Su  3:26 pm Last Quarter
    19  We  7:37 pm Moon-Aldebaran: 0.4° S
    20  Th  7:13 am Moon-Venus: 2.7° N
    21  Fr  1:09 pm Moon Perigee: 361200 km
    21  Fr  6:11 pm Moon North Dec.: 19.4° N
    23  Su  5:46 am New Moon
    24  Mo  8:47 pm Moon Ascending Node
    25  Tu  4:49 am Moon-Mercury: 0.9° S
    25  Tu  6:14 am Moon-Regulus: 0°
    25  Tu  1:07 pm Mercury-Regulus: 0.9° S
    26  We  7:59 pm Mars Conjunction
    27  Th 10:41 pm Delta Aquariid Meteor Shower: ZHR = 20
    28  Fr  4:15 pm Moon-Jupiter: 3.4° S
    29  Sa 11:59 pm Mercury Elongation: 27.2° E
    30  Su 11:23 am First Quarter
Aug 01  Tu       Venus: 38.4° 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.

July Rising and Setting Events

     LU                  Ephemeris of Sky Events for Interlochen/TC
July, 2017    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Sat  1| 06:01a  09:32p  15:30 | 10:57p  04:35a |      Set  02:16a   60%|
+------+-----------------------+----------------+-----------------------+
|Sun  2| 06:01a  09:31p  15:29 | 10:56p  04:36a |      Set  02:44a   69%|
|Mon  3| 06:02a  09:31p  15:29 | 10:56p  04:37a |      Set  03:13a   77%|
|Tue  4| 06:03a  09:31p  15:28 | 10:55p  04:38a |      Set  03:46a   85%|
|Wed  5| 06:03a  09:30p  15:27 | 10:55p  04:39a |      Set  04:22a   91%|
|Thu  6| 06:04a  09:30p  15:26 | 10:54p  04:39a |      Set  05:02a   96%|
|Fri  7| 06:05a  09:30p  15:24 | 10:54p  04:40a |      Set  05:48a   99%|
|Sat  8| 06:05a  09:29p  15:23 | 10:53p  04:41a |      Set  06:38a  100%|
+------+-----------------------+----------------+-----------------------+
|Sun  9| 06:06a  09:29p  15:22 | 10:52p  04:43a |Full  Rise 09:45p   99%|
|Mon 10| 06:07a  09:28p  15:21 | 10:51p  04:44a |      Rise 10:25p   97%|
|Tue 11| 06:08a  09:28p  15:19 | 10:50p  04:45a |      Rise 11:00p   92%|
|Wed 12| 06:09a  09:27p  15:18 | 10:49p  04:46a |      Rise 11:32p   86%|
|Thu 13| 06:09a  09:26p  15:16 | 10:48p  04:47a |      Rise 12:03a   78%|
|Fri 14| 06:10a  09:26p  15:15 | 10:47p  04:48a |      Rise 12:32a   69%|
|Sat 15| 06:11a  09:25p  15:13 | 10:46p  04:49a |      Rise 01:02a   59%|
+------+-----------------------+----------------+-----------------------+
|Sun 16| 06:12a  09:24p  15:12 | 10:45p  04:51a |L Qtr Rise 01:33a   48%|
|Mon 17| 06:13a  09:23p  15:10 | 10:44p  04:52a |      Rise 02:08a   37%|
|Tue 18| 06:14a  09:23p  15:08 | 10:43p  04:53a |      Rise 02:47a   26%|
|Wed 19| 06:15a  09:22p  15:06 | 10:42p  04:55a |      Rise 03:33a   16%|
|Thu 20| 06:16a  09:21p  15:04 | 10:41p  04:56a |      Rise 04:26a    8%|
|Fri 21| 06:17a  09:20p  15:02 | 10:39p  04:57a |      Rise 05:28a    3%|
|Sat 22| 06:18a  09:19p  15:00 | 10:38p  04:59a |      Rise 06:35a    0%|
+------+-----------------------+----------------+-----------------------+
|Sun 23| 06:19a  09:18p  14:58 | 10:37p  05:00a |New   Set  09:31p    1%|
|Mon 24| 06:20a  09:17p  14:56 | 10:35p  05:01a |      Set  10:13p    3%|
|Tue 25| 06:21a  09:16p  14:54 | 10:34p  05:03a |      Set  10:49p    9%|
|Wed 26| 06:22a  09:15p  14:52 | 10:32p  05:04a |      Set  11:21p   16%|
|Thu 27| 06:23a  09:14p  14:50 | 10:31p  05:06a |      Set  11:50p   25%|
|Fri 28| 06:24a  09:13p  14:48 | 10:29p  05:07a |      Set  12:18a   34%|
|Sat 29| 06:25a  09:11p  14:45 | 10:28p  05:09a |      Set  12:46a   44%|
+------+-----------------------+----------------+-----------------------+
|Sun 30| 06:27a  09:10p  14:43 | 10:26p  05:10a |F Qtr Set  01:15a   53%|
|Mon 31| 06:28a  09:09p  14:41 | 10:25p  05:12a |      Set  01:47a   63%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise

Above created using my LookingUp program for MS-DOS