Bob Moler's Ephemeris Blog

Ephemeris for Good Friday, Friday, March 30th. The Sun will rise at 7:27. It’ll be up for 12 hours and 40 minutes, setting at 8:07. The Moon, 1 day before full, will set at 7:50 tomorrow morning.

The 4th month of the year begins on Sunday. Daylight hours in the Interlochen/Traverse City area and will increase from 12 hours and 46 minutes Sunday to 14 hours 12 minutes on April 30th. The altitude, or angle, of the Sun above the southern horizon at local noon will be 50 degrees Sunday and will ascend to 60 degrees on April 30th. The altitude of the Sun in the Straits area will be a degree lower. The actual time of local apparent noon when the sun passes due south, will be about 1:43 p.m. The Lyrid meteor shower will reach it’s peak on the early afternoon of the 22nd. So the early morning hours between 3 and 5 a.m. are the best time to see it when the Moon has set and the radiant is high in the sky.

Addendum

April Evening Sky Chart

Star Chart for April 2018 (10 p.m. EDT April 15, 2018). 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 5 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.

Note the chart times of 10 p.m. and 5 a.m. are for the 15th. For each week before the 15th add ½ hour (28 minutes if you’re picky). Watch out for the time change. 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.

April Morning Star Chart

Star Chart for April 2018 mornings based on 5 a.m. April 15th. Created using my LookingUp program. Click on image to enlarge.

For a list of constellation names to go with the abbreviations click here.

Star chart annotations

• 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.
• LyrR is the Lyrid meteor shower radiant.  The Lyrid meteor shower will reach its peak for us on the morning of the 22nd. The actual peak time is variable for this shower and can occur as early as 6 a.m. to as late as 5 p.m. Also the peak numbers of meteors are variable. Best time to observe without the Moon is between 3 a.m. and the start of twilight.

Twilight

Evening nautical twilight ends at 9:17 p.m. EDT on the 1st, increasing to 10:00 p.m. EDT on the 30th.
Evening astronomical twilight ends at 9:54 p.m. EDT on the 1st, increasing to 10:44 p.m. EDT on the 30th.
Morning astronomical twilight starts at 5:47 a.m. EDT on the 1st, and decreasing to 4:43 a.m. EDT on the 30th.
Morning nautical twilight starts at 6:23 a.m. EDT on the 1st, and decreasing to 5:27 a.m. EDT on the 30th.

NASA Calendar of Planetary Events

    Date    Time    Event
Apr 01  Su          Venus: 19.9° E
    01  Su  1:47 pm Mercury Inferior Conj.
    02  Mo  3:02 pm Mars-Saturn: 1.3° N
    03  Tu 10:14 am Moon-Jupiter: 4.2° S
    07  Sa  8:50 am Moon-Saturn: 2.1° S
    07  Sa 10:37 am Moon South Dec.: 20.3° S
    07  Sa  2:15 pm Moon-Mars: 3.5° S
    08  Su  1:32 am Moon Apogee: 404100 km
    08  Su  3:18 am Last Quarter
    10  Tu  4:09 am Moon Descending Node
    15  Su  9:57 pm New Moon
    17  Tu  3:29 pm Moon-Venus: 5.5° N
    18  We 10:35 am Uranus Conjunction
    19  Th 12:45 am Moon-Aldebaran: 1.1° S
    20  Fr 10:44 am Moon Perigee: 368700 km
    21  Sa  3:38 am Moon North Dec.: 20.4° N
    22  Su  1:49 pm Lyrid Shower: ZHR = 20
    22  Su  5:46 pm First Quarter
    23  Mo  2:17 am Moon-Beehive: 2° N
    23  Mo  8:19 am Moon Ascending Node
    24  Tu 12:47 pm Venus-Pleiades: 3.5° S
    24  Tu  3:39 pm Moon-Regulus: 1.2° S
    29  Su  1:59 pm Mercury Elongation: 27° W
    29  Su  8:58 pm Full Moon
    30  Mo  1:16 pm Moon-Jupiter: 4.1° S
May 01  Tu          Venus: 27.2° 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
     April, 2018    Local time zone: EDT
     +-----------------------------------------------------------------------+
     | DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
     |      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
     +=======================================================================+
     |Sun  1| 07:23a  08:10p  12:46 | 09:15p  06:19a |      Rise 09:35p   97%|
     |Mon  2| 07:21a  08:11p  12:49 | 09:16p  06:17a |      Rise 10:40p   93%|
     |Tue  3| 07:19a  08:12p  12:53 | 09:18p  06:15a |      Rise 11:44p   87%|
     |Wed  4| 07:18a  08:14p  12:56 | 09:19p  06:13a |      Rise 12:44a   80%|
     |Thu  5| 07:16a  08:15p  12:59 | 09:20p  06:11a |      Rise 01:41a   71%|
     |Fri  6| 07:14a  08:16p  13:02 | 09:22p  06:09a |      Rise 02:33a   62%|
     |Sat  7| 07:12a  08:17p  13:05 | 09:23p  06:07a |      Rise 03:20a   53%|
     +------+-----------------------+----------------+-----------------------+
     |Sun  8| 07:10a  08:19p  13:08 | 09:25p  06:05a |L Qtr Rise 04:03a   43%|
     |Mon  9| 07:09a  08:20p  13:11 | 09:26p  06:03a |      Rise 04:40a   34%|
     |Tue 10| 07:07a  08:21p  13:14 | 09:28p  06:01a |      Rise 05:14a   25%|
     |Wed 11| 07:05a  08:22p  13:17 | 09:29p  05:59a |      Rise 05:45a   17%|
     |Thu 12| 07:03a  08:24p  13:20 | 09:31p  05:57a |      Rise 06:14a   11%|
     |Fri 13| 07:01a  08:25p  13:23 | 09:32p  05:55a |      Rise 06:42a    5%|
     |Sat 14| 07:00a  08:26p  13:26 | 09:34p  05:53a |      Rise 07:10a    2%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 15| 06:58a  08:27p  13:29 | 09:35p  05:51a |New   Set  08:05p    0%|
     |Mon 16| 06:56a  08:29p  13:32 | 09:37p  05:49a |      Set  09:16p    1%|
     |Tue 17| 06:55a  08:30p  13:35 | 09:38p  05:47a |      Set  10:27p    5%|
     |Wed 18| 06:53a  08:31p  13:38 | 09:40p  05:45a |      Set  11:38p   11%|
     |Thu 19| 06:51a  08:32p  13:41 | 09:41p  05:43a |      Set  12:47a   19%|
     |Fri 20| 06:50a  08:34p  13:44 | 09:43p  05:41a |      Set  01:50a   29%|
     |Sat 21| 06:48a  08:35p  13:47 | 09:44p  05:39a |      Set  02:46a   40%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 22| 06:46a  08:36p  13:49 | 09:46p  05:37a |F Qtr Set  03:34a   51%|
     |Mon 23| 06:45a  08:37p  13:52 | 09:47p  05:35a |      Set  04:15a   62%|
     |Tue 24| 06:43a  08:39p  13:55 | 09:49p  05:33a |      Set  04:51a   73%|
     |Wed 25| 06:41a  08:40p  13:58 | 09:50p  05:31a |      Set  05:22a   82%|
     |Thu 26| 06:40a  08:41p  14:01 | 09:52p  05:29a |      Set  05:52a   90%|
     |Fri 27| 06:38a  08:42p  14:04 | 09:53p  05:28a |      Set  06:20a   95%|
     |Sat 28| 06:37a  08:44p  14:06 | 09:55p  05:26a |      Set  06:48a   99%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 29| 06:35a  08:45p  14:09 | 09:57p  05:24a |Full  Rise 08:25p  100%|
     |Mon 30| 06:34a  08:46p  14:12 | 09:58p  05:22a |      Rise 09:30p   99%|
     +-----------------------------------------------------------------------+
     * Nautical Twilight
     ** Moonrise or moonset, whichever occurs between sunset and sunrise

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