04/01/2019 – Ephemeris – Previewing April skies

Ephemeris for April Fools Day, Monday, April 1st. Today the Sun will be up for 12 hours and 46 minutes, setting at 8:10, and it will rise tomorrow at 7:22. The Moon, half way from last quarter to new, will rise at 6:37 tomorrow morning.

Last year we were fooled by an abundance of snow in April. Hopefully we won’t be tricked again. Daylight hours in the Interlochen/Traverse City area and will increase from 12 hours and 46 minutes today to 14 hours 11 minutes on the 30th. The altitude, or angle, of the Sun above the southern horizon at local noon will ascend from 50 degrees today to 60 degrees on the 30th. The altitude of the Sun in the Straits area will be a degree lower, but their daylight hours will be a bit longer. The actual time of local apparent noon this month for the Interlochen/Traverse City area, when the Sun passes due south, will be about 1:43 p.m. This month Mars will be our only evening planet.

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

Addendum

April Evening Star Chart

Star Chart for April 2019 (10 p.m. EDT April 15, 2019). Created using my LookingUp program. Click on image to enlarge.

The planets and stars are plotted for the 15th at 10 p.m. EST 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.

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). 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 mornings 2019 (5 a.m. EST April 15, 2019). 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, and
• Extend like a spike to Spica,
• The Summer Triangle is in red.
• LyrR is the radiant of the Lyrid meteor shower that peaks on the 22nd.

Twilight Limits, Nautical and Astronomical

			EDT
Traverse City	Morning twilight		Evening twilight		Dark night		Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2019-04-01	5h47m	6h24m	21h17m	21h53m	21h53m	5h47m	0.13
2019-04-02	5h45m	6h22m	21h18m	21h55m	21h55m	5h45m	0.07
2019-04-03	5h43m	6h20m	21h20m	21h57m	21h57m	5h43m	0.03
2019-04-04	5h41m	6h18m	21h21m	21h58m	21h58m	5h41m	0
2019-04-05	5h38m	6h16m	21h22m	22h00m	22h00m	5h38m	0
2019-04-06	5h36m	6h14m	21h24m	22h01m	22h01m	5h36m	0.02
2019-04-07	5h34m	6h12m	21h25m	22h03m	22h48m	5h34m	0.06
2019-04-08	5h32m	6h10m	21h27m	22h05m	23h54m	5h32m	0.12
2019-04-09	5h30m	6h08m	21h28m	22h06m	–	5h30m	0.2
2019-04-10	5h27m	6h06m	21h30m	22h08m	1h00m	5h27m	0.3
2019-04-11	5h25m	6h04m	21h31m	22h10m	2h04m	5h25m	0.41
2019-04-12	5h23m	6h02m	21h33m	22h11m	3h03m	5h23m	0.53
2019-04-13	5h21m	6h00m	21h34m	22h13m	3h55m	5h21m	0.64
2019-04-14	5h19m	5h58m	21h36m	22h15m	4h40m	5h19m	0.75
2019-04-15	5h16m	5h56m	21h37m	22h16m	–	–	0.85
2019-04-16	5h14m	5h54m	21h39m	22h18m	–	–	0.93
2019-04-17	5h12m	5h52m	21h40m	22h20m	–	–	0.93
2019-04-18	5h10m	5h50m	21h42m	22h22m	–	–	0.98
2019-04-19	5h07m	5h48m	21h43m	22h24m	–	–	1
2019-04-20	5h05m	5h46m	21h45m	22h25m	–	–	0.99
2019-04-21	5h03m	5h44m	21h46m	22h27m	22h27m	23h19m	0.96
2019-04-22	5h01m	5h42m	21h48m	22h29m	22h29m	–	0.9
2019-04-23	4h59m	5h40m	21h49m	22h31m	22h31m	0h24m	0.82
2019-04-24	4h56m	5h38m	21h51m	22h33m	22h33m	1h24m	0.74
2019-04-25	4h54m	5h36m	21h52m	22h34m	22h34m	2h16m	0.64
2019-04-26	4h52m	5h35m	21h54m	22h36m	22h36m	3h01m	0.54
2019-04-27	4h50m	5h33m	21h55m	22h38m	22h38m	3h39m	0.45
2019-04-28	4h48m	5h31m	21h57m	22h40m	22h40m	4h12m	0.35
2019-04-29	4h45m	5h29m	21h58m	22h42m	22h42m	4h41m	0.26
2019-04-30	4h43m	5h27m	22h00m	22h44m	22h44m	4h43m	0.18

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			Local Time	Event
Apr	1	Mo		        Venus: 34.6° W
 	2	Tu	12:17 AM	Moon-Venus: 3° N
 	2	Tu	07:01 PM	Moon-Mercury: 4° N
 	5	Fr	04:50 AM	New Moon
 	9	Tu	02:40 AM	Moon-Mars: 5° N
 	9	Tu	11:43 AM	Moon-Aldebaran: 2.2° S
 	11	Th	02:59 PM	Mercury Elongation: 27.7° W
 	11	Th	07:59 PM	Moon North Dec.: 22° N
 	12	Fr	02:08 PM	Moon Ascending Node
 	12	Fr	03:06 PM	First Quarter
 	13	Sa	04:12 PM	Moon-Beehive: 0.2° N
 	14	Su	08:08 PM	Mars-Aldebaran: 6.5° N
 	15	Mo	04:22 AM	Moon-Regulus: 2.7° S
 	16	Tu	02:03 PM	Mercury-Venus: 4.3° N
 	16	Tu	06:02 PM	Moon Perigee: 364200 km
 	19	Fr	07:12 AM	Full Moon
 	22	Mo	07:58 PM	Lyrid Shower: ZHR = 20
 	22	Mo	08:06 PM	Uranus Conjunction
 	23	Tu	07:36 AM	Moon-Jupiter: 1.8° S
 	24	We	05:22 PM	Moon South Dec.: 22.1° S
 	25	Th	10:38 AM	Moon-Saturn: 0.4° N
 	25	Th	11:02 AM	Moon Descending Node
 	26	Fr	06:18 PM	Last Quarter
 	28	Su	02:20 PM	Moon Apogee: 404600 km
May	1	We		        Venus: 27.8° W
All event times are given for UTC-5 hr: Eastern Standard or UTC-4 hr: Daylight Saving Time starting April 10th.

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

Ephemeris of Sky Events for NMC Observatory
April, 2019 – Local time zone: EDT
Date		Sun			Twilight*		Moon			Illum
		Rise	Set	Hours	End	Start	Phase	R/S**	Time	Fractn
Mon	1	07:23a	08:09p	12:45	09:14p	06:19a		Rise	06:37a	10%
Tue	2	07:21a	08:10p	12:49	09:15p	06:17a		Rise	07:02a	5%
Wed	3	07:20a	08:12p	12:52	09:17p	06:15a		Rise	07:26a	2%
Thu	4	07:18a	08:13p	12:55	09:18p	06:13a		Rise	07:50a	0%
Fri	5	07:16a	08:14p	12:58	09:19p	06:11a	New	Set	08:37p	1%
Sat	6	07:14a	08:15p	13:01	09:21p	06:09a		Set	09:41p	3%
Sun	7	07:12a	08:17p	13:04	09:22p	06:07a		Set	10:47p	7%
Mon	8	07:11a	08:18p	13:07	09:24p	06:05a		Set	11:53p	13%
Tue	9	07:09a	08:19p	13:10	09:25p	06:03a		Set	12:59a	21%
Wed	10	07:07a	08:20p	13:13	09:27p	06:01a		Set	02:03a	31%
Thu	11	07:05a	08:22p	13:16	09:28p	05:59a		Set	03:02a	41%
Fri	12	07:03a	08:23p	13:19	09:30p	05:57a	F Qtr	Set	03:54a	52%
Sat	13	07:02a	08:24p	13:22	09:31p	05:55a		Set	04:39a	64%
Sun	14	07:00a	08:25p	13:25	09:33p	05:53a		Set	05:18a	74%
Mon	15	06:58a	08:27p	13:28	09:34p	05:51a		Set	05:52a	84%
Tue	16	06:57a	08:28p	13:31	09:35p	05:49a		Set	06:23a	91%
Wed	17	06:55a	08:29p	13:34	09:37p	05:47a		Set	06:52a	97%
Thu	18	06:53a	08:30p	13:37	09:38p	05:45a		Set	07:22a	100%
Fri	19	06:51a	08:32p	13:40	09:40p	05:43a	Full	Rise	08:55p	99%
Sat	20	06:50a	08:33p	13:43	09:42p	05:41a		Rise	10:08p	97%
Sun	21	06:48a	08:34p	13:45	09:43p	05:39a		Rise	11:18p	92%
Mon	22	06:46a	08:35p	13:48	09:45p	05:38a		Rise	12:24a	85%
Tue	23	06:45a	08:37p	13:51	09:46p	05:36a		Rise	01:23a	77%
Wed	24	06:43a	08:38p	13:54	09:48p	05:34a		Rise	02:15a	68%
Thu	25	06:42a	08:39p	13:57	09:49p	05:32a		Rise	03:00a	59%
Fri	26	06:40a	08:40p	14:00	09:51p	05:30a	L Qtr	Rise	03:38a	49%
Sat	27	06:39a	08:41p	14:02	09:52p	05:28a		Rise	04:11a	40%
Sun	28	06:37a	08:43p	14:05	09:54p	05:26a		Rise	04:40a	31%
Mon	29	06:36a	08:44p	14:08	09:55p	05:24a		Rise	05:06a	23%
Tue	30	06:34a	08:45p	14:11	09:57p	05:23a		Rise	05:30a	15%
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise