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05/10/2022 – Ephemeris – Event Horizon Telescope Collaboration will announce “groundbreaking Milky Way results” on Thursday

May 10, 2022 Comments off

This is Ephemeris for Tuesday, May 10th. Today the Sun will be up for 14 hours and 38 minutes, setting at 8:58, and it will rise tomorrow at 6:19. The Moon, 2 days past first quarter, will set at 4:25 tomorrow morning.

This Thursday, May 12th at 13:00 UT (9 am our time EDT) the Event Horizon Telescope Collaboration will announce “groundbreaking Milky Way results.” Their words. Their first groundbreaking result came in three years ago with the release of an image of the billion solar mass black hole in the heart of the giant galaxy M 87 over 50 million light years away. Beforehand, I was expecting the results to concern a more nearby black hole called Sagittarius A* (pronounced Sagittarius A Star) at the center of our galaxy, only 25 to 27 thousand light years away. That turned out to be much more difficult than the one in M 87, due to the amount of dust and gas in the way. So maybe this time they have done it. We’ll all find out this Thursday.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Black hole in M87

The first image of the black hole in M87. Credit Event Horizon Telescope.

The Event Horizon Telescope isn’t a single telescope. But millimeter wavelength radio telescopes spaced out to use the diameter of the Earth as its simulated aperture. The ability to resolve tiny objects at great distances depends on the wavelength of the radiation and the size of the telescope aperture. So the smaller the wavelength and the larger the aperture, the greater the resolution of the telescope or array.

The observation of all the telescopes must be performed at the same time, recording the observations on terabyte magnetic disks. The disks are brought to a single location for processing together to actually produce the image, which takes a while.

Event Horizon Telescope

Event Horizon Telescope component radio telescopes. Credits: © APEX, IRAM, G. Narayanan, J. McMahon, JCMT/JAC, S. Hostler, D. Harvey, ESO/C. Malin.

05/09/2022 – Ephemeris – Monday’s Moon

May 9, 2022 Comments off

This is Bob Moler with Ephemeris for Monday, May 9th. Today the Sun will be up for 14 hours and 35 minutes, setting at 8:57, and it will rise tomorrow at 6:20. The Moon, 1 day past first quarter, will set at 4:03 tomorrow morning.

Nothing is more fun than to look at the Moon through binoculars or a small telescope around its first quarter phase. The little gray oval on the face of the Moon on its upper right, not connected to all the other gray areas, is called the Sea of Crises or Mare Crisium. I use Mare Crisium as a telltale for the Moon’s libration or wobble. Tonight Crisium is close to the edge of the Moon, so on a day after first quarter, we’re seeing somewhat more territory on the left side of the Moon than we normally would at this phase. At the bottom or south end of the Moon are two prominent craters visible even in binoculars, the small but distinct Tycho, and the much larger Clavius, whose floor contains other craters and is convex following the curvature of the Moon.

Reminder: There will be a total lunar eclipse occurring a week from this morning, actually starting Sunday evening Eastern Daylight Time. I’ll give you full details later in the week. That’s the evening of May 15th, through morning of the 16th.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

8-day old Moon

The 8-day-old Moon labeled via animated GIF, as it would appear in binoculars or a small telescope tonight, May 9, 2022. Created using Virtual Moon Atlas, GIMP and LibreOffice Draw.

Translations

Mare Crisium – Sea of Crises
Mare Fecunditatis – Sea of Fertility
Mare Frigoris – Sea of Cold
Mare Imbrium – Sea of Showers
Mare Nectaris – Sea of Nectar
Mare Nubium – Sea of Clouds
Mare Serenitatis – Sea of Serenity
Mare Tranquillitatis – Sea of Tranquility
Sinus Medii – Bay of the Center

Note that Mare is pronounced Mar-é

05/06/2022 – Ephemeris – Tonight: wander through the celestial wonders in Sagittarius

May 6, 2022 Comments off

This is Ephemeris for Friday, May 6th. Today the Sun will be up for 14 hours and 28 minutes, setting at 8:53, and it will rise tomorrow at 6:24. The Moon, 2 days before first quarter, will set at 2:35 tomorrow morning.

Tonight at 8 pm, the Grand Traverse Astronomical Society will have an in-person meeting at Northwestern Michigan College’s Rogers Observatory. The meeting will also be available via Zoom. The program will be presented by Dan Dall’Olmo. Who spends many of his nights photographing the heavens. He will show the wonders in and around the Milky Way in the summer constellation of Sagittarius. It’s just the thing to prepare us for the wonderful dark nights of August. If it’s clear, there will be a star party following the meeting. The observatory is located south of Traverse City off Birmley Road, between Garfield and Keystone roads. A Zoom link is available at gtastro.org.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

05/05/2022 – Ephemeris – Halley’s Comet returns… in pieces

May 5, 2022 Comments off

This is Ephemeris for Cinco de Mayo, Thursday, May 5th. Today the Sun will be up for 14 hours and 25 minutes, setting at 8:52, and it will rise tomorrow at 6:25. The Moon, 3 days before first quarter, will set at 1:53 tomorrow morning.

The Eta Aquariid meteor shower will reach peak at about 4 am, tomorrow morning. However, the radiant, the apparent source of the meteor streaks, doesn’t rise until 3:15 am. If you’re waiting to see the return of Halley’s Comet, you needn’t wait until the main body of the comet returns in 2061. Halley’s Comet has made many passes of the inner solar system in recorded history, and more before that, returning to the inner solar system every 76 years or so, before returning to its frigid home beyond Neptune. It’s closest pass to the Sun, called perihelion, is inside Venus’ orbit. On the way in and out, it passes close to the Earth’s orbit. It has left a trail of debris, which we pass through in May and again in October.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Eta Aquariid radiant

The Eta Aquariid meteor shower radiant as it will be apparent tomorrow morning at 4:30 or at the beginning of nautical twilight. The radiant isn’t a ting that can be seen, but the point from which all the meteors of this shower can be traced back to. The funny looking lower case “n” is the Greek letter eta. The shower is named for the star seen just above the radiant, which is in the center of a small triangle of stars that make up Aquarius’ water jar. Click on the image to enlarge it. Created using Stellarium.

05/04/2022 – Ephemeris – Let’s search for the naked-eye planets for this week

May 4, 2022 Comments off

This is Ephemeris for Wednesday, May 4th. Today the Sun will be up for 14 hours and 23 minutes, setting at 8:51, and it will rise tomorrow at 6:27. The Moon, halfway from new to first quarter, will set at 1:03 tomorrow morning.

Let’s search for the naked-eye planets for this week. There is one bright planet in the evening sky. Mercury may be spotted around and after 10 this evening very low in the west-northwest and be visible for the next half hour or so before it sets at 10:40 pm. After that, the planet action shifts to the morning sky. The other 4 naked-eye planets are there. By 5:30 or 5:45 am, the planets will be spread out low from the east to southeast with brilliant Venus lowest in the east, higher and right is Jupiter. Dim Mars will be farther to the right and a bit above Jupiter, while brighter Saturn will be even farther right and above Mars. All four will have risen by 5 am, but it will take a very low eastern horizon to pick them all up at that time.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Mercury in evening twilight

Mercury in evening twilight, with competition from bright winter stars and the Moon at 10 pm, or about an hour after sunset. It might take a pair of binoculars to pick Mercury out of twilight.
Created using Stellarium.

Binocular Moon

The Moon as it might appear in binoculars tonight, showing earth shine. May 4, 2022. Created using Stellarium.

Morning planet parade

The morning planet parade is widening as Venus is moving away from Jupiter, and Mars is approaching the giant planet. These are shown at 5:30 am, or about an hour before sunrise. Created using Stellarium.

Telescopic views of Venus, Saturn and Jupiter

Views of Venus, Jupiter, and Saturn (north up) as they would be seen in a small telescope, with the same magnification, tomorrow morning at 5:30 am, May 5, 2022. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Venus 16.33″, 68.7% illuminated; Saturn 16.60″, its rings 38.67″; Jupiter 35.09″. Mars is not shown, its apparent diameter is 5.84″ and is 89.1% illuminated. Mercury, in the evening, has an apparent diameter of 9.21″, and it’s 22.2% illuminated. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

Planets and the Moon on a single night

The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on May 4, 2022. The night ends on the left with sunrise on the 5th. Notice that all the naked-eye planets except Mercury are in the morning sky now. Click on the image to enlarge it. Created using my LookingUp program.

05/03/2022 – Ephemeris – Regulus, the “Little King Star”

May 3, 2022 Comments off

This is Bob Moler with Ephemeris for Tuesday, May 3rd. Today the Sun will be up for 14 hours and 20 minutes, setting at 8:50, and it will rise tomorrow at 6:28. The Moon, 3 days past new, will set at 12:05 tomorrow morning.

Fairly high in the south-southwest at 10 p.m. is a pattern of stars that’s in the shape of a backward question mark. This informal star group or asterism is also called the sickle. It is the head and mane of the official zodiacal constellation of Leo the lion. To the left is a triangle of stars is his hind end. The bright star at the bottom of the question mark, or end of the sickle’s handle is Regulus, the “Little King Star”, alluding to the lion’s status as the king of the jungle. Regulus is about 79 light years away and is a 4 star system that exists as two star pairs. The bright star Regulus itself and a companion too close to be imaged directly in telescopes, and a nearby pair of dim stars make up the system. The Moon often passes in front of Regulus, since it’s close to the ecliptic. These occultations, as they are called, will occur monthly for a year and a half starting July

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Finder chart for Leo and Regulus

Animated finder chart for Leo and Regulus for early May at 10 pm or an hour after sunset. The orange line that appears is the ecliptic, the path of the Sun in the sky. The path of the Moon is tilted by about 5 degrees to that path. The paths cross at points called nodes. The nodes move slowly westward in an 18.6-year cycle called the regression of the nodes. Occultations of Regulus by the Moon occur during two periods in that cycle. The next period where occultations of Regulus will occur monthly from July 2025 to January 2027. Created using Stellarium and GIMP.

Occultations are like solar eclipses in that they can only be seen from a limited area. That area will shift southward during that period. Of the 21 occultations in that period, only 2 will be visible from the United States: February 3rd, and April 26th 2026.

05/02/2022 – Ephemeris – The Moon and Mercury together where we can see them

May 2, 2022 Comments off

This is Bob Moler with Ephemeris for Monday, May 2nd. Today the Sun will be up for 14 hours and 17 minutes, setting at 8:49, and it will rise tomorrow at 6:29. The Moon, 2 days past new, will set at 11:02 this evening.

The two-day-old thin sliver of a Moon will be left and above Mercury this evening. About the best time to spot them is between 9:30 and 10:15 pm, low in the western sky. They will be seen in the west-northwest. As we move through the week, the Moon will move away from Mercury to the east, while Mercury heads back toward the Sun and, dimming as it goes. Mercury is the closest planet to the Sun and averages 40 percent of the Earth’s distance from the Sun, so it is never seen at our northerly latitude outside of twilight. Mercury has the most elliptical orbit of the major planets. And it happens that at the best times to see Mercury, on spring evenings and autumn mornings, Mercury is at its nearest to the Sun. Southern Hemisphere observers get a better look at it because their best observing times are when Mercury is farthest from the Sun.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Mercury and the 2-day-old Moon

Mercury and the 2-day-old Moon as they might appear at 9:30 pm, or about 40 minutes after sunset tonight, May 2, 2022, looking low to the west-northwest. Aldebaran, slightly dimmer than Mercury, is the star to the left of the Moon. Created using Stellarium.

04/29/2022 – Ephemeris – Previewing the skies of May 2022

April 29, 2022 Comments off

This is Bob Moler with Ephemeris for Arbor Day, Friday, April 29th. Today the Sun will be up for 14 hours and 9 minutes, setting at 8:45, and it will rise tomorrow at 6:34. The Moon, 1 day before new, will rise at 6:36 tomorrow morning.

Let’s look at the month of May’s skies. Daylight hours in the Interlochen/Traverse City area will increase from 14 hours and 15 minutes this Sunday the 1st to 15 hours 19 minutes on May 31st. The altitude, or angle, of the Sun above the southern horizon at local noon will ascend from 60 degrees Sunday to 67 degrees at month’s end. The altitude of the Sun in the Straits area will be a degree lower than that but your length of daylight will be a few minutes longer. Local apparent noon this month, when the Sun passes due south, will be about 1:38 p.m. The Eta Aquariid meteor shower will reach its peak about 3 a.m. on the 5th. The big event this month will be a total eclipse of the Moon starting late Sunday evening the 15th.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

May Evening Star Chart

May 2022 Evening Star Chart

Star Chart for May 2022 (11 p.m. EDT May 15, 2022). Click on image to enlarge. Created using my LookingUp program. Click on image to enlarge. Created using my LookingUp program.

The planets and stars are plotted for the 15th at 11 p.m. EDT in the evening and 4 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 11 p.m. and 4 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, or 28 minutes. 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 for weekly positions.

May Morning Star Chart

Star Chart May 2022 Morning

Star Chart for May mornings, 2022 (4 a.m. EDT, May 15, 2022). Click on image to enlarge. Created using my LookingUp program.

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,
  • EaqR is the radiant of the Eta Aquariid meteor shower that peaks on the 6th.

Twilight Limits, Nautical and Astronomical

EDT
Morning Twilight Evening Twilight Dark Night Moon
Date Astro. Nautical Nautical Astro. Start End Illum.
2021-05-01 4h40m 5h24m 22h02m 22h47m 22h47m 1h35m 0.67
2021-05-02 4h38m 5h23m 22h04m 22h49m 22h49m 2h32m 0.57
2021-05-03 4h36m 5h21m 22h05m 22h51m 22h51m 3h17m 0.46
2021-05-04 4h33m 5h19m 22h07m 22h53m 22h53m 3h52m 0.36
2021-05-05 4h31m 5h17m 22h09m 22h55m 22h55m 4h20m 0.27
2021-05-06 4h29m 5h16m 22h10m 22h57m 22h57m 4h29m 0.18
2021-05-07 4h27m 5h14m 22h12m 22h59m 22h59m 4h27m 0.11
2021-05-08 4h25m 5h12m 22h13m 23h01m 23h01m 4h25m 0.06
2021-05-09 4h23m 5h11m 22h15m 23h03m 23h03m 4h23m 0.02
2021-05-10 4h21m 5h09m 22h16m 23h05m 23h05m 4h21m 0
2021-05-11 4h19m 5h07m 22h18m 23h07m 23h07m 4h19m 0
2021-05-12 4h17m 5h06m 22h19m 23h09m 23h09m 4h17m 0.02
2021-05-13 4h15m 5h04m 22h21m 23h11m 23h11m 4h15m 0.05
2021-05-14 4h13m 5h03m 22h23m 23h13m 4h13m 0.1
2021-05-15 4h11m 5h01m 22h24m 23h15m 0h07m 4h11m 0.17
2021-05-16 4h09m 5h00m 22h26m 23h17m 1h00m 4h09m 0.25
2021-05-17 4h07m 4h58m 22h27m 23h19m 1h46m 4h07m 0.34
2021-05-18 4h05m 4h57m 22h28m 23h21m 2h25m 4h05m 0.44
2021-05-19 4h03m 4h56m 22h30m 23h23m 2h58m 4h03m 0.54
2021-05-20 4h01m 4h54m 22h31m 23h24m 3h26m 4h01m 0.65
2021-05-21 4h00m 4h53m 22h33m 23h26m 3h51m 4h00m 0.76
2021-05-22 3h58m 4h52m 22h34m 23h28m 0.85
2021-05-23 3h56m 4h51m 22h36m 23h30m 0.92
2021-05-24 3h54m 4h49m 22h37m 23h32m 0.98
2021-05-25 3h53m 4h48m 22h38m 23h34m 1
2021-05-26 3h51m 4h47m 22h40m 23h36m 0.99
2021-05-27 3h49m 4h46m 22h41m 23h38m 0.95
2021-05-28 3h48m 4h45m 22h42m 23h39m 23h39m 0.89
2021-05-29 3h46m 4h44m 22h43m 23h41m 23h41m 0h19m 0.81
2021-05-30 3h45m 4h43m 22h45m 23h43m 23h43m 1h11m 0.72
2021-05-31 3h44m 4h42m 22h46m 23h44m 23h44m 1h52m 0.61

The twilight calendar was generated using Cartes du Ciel (Sky Charts), with some corrections.

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     Time     Event
May  1  Su            Venus: 42.4° W
     1  Su   3:52 pm  Moon Ascending Node
     2  Mo  10:17 am  Moon-Mercury: 2° N
     5  Th   4:57 am  Uranus Conjunction
     5  Th   8:46 am  Moon Apogee: 405300 km
     5  Th  11:55 am  Moon North Dec.: 27° N
     6  Fr   4:00 am  Eta Aquarid Shower: ZHR = 60
     6  Fr   6:56 pm  Moon-Pollux: 2.3° N
     7  Sa   8:23 pm  Moon-Beehive: 4° S
     8  Su   8:21 pm  First Quarter
    15  Su   7:44 pm  Moon Descending Node
    16  Mo  12:11 am  Total Lunar Eclipse
    16  Mo  12:14 am  Full Flower Moon
    17  Tu  11:23 am  Moon Perigee: 360300 km
    18  We   9:21 pm  Moon South Dec.: 27° S
    21  Sa   3:14 pm  Mercury Inferior Conj.
    22  Su  12:43 am  Moon-Saturn: 4.6° N
    22  Su   2:43 pm  Last Quarter
    24  Tu   3:24 pm  Moon-Mars: 2.9° N
    24  Tu   7:59 pm  Moon-Jupiter: 3.4° N
    26  Th  10:52 pm  Moon-Venus: 0.2° N
    28  Sa  10:33 pm  Moon Ascending Node
    29  Su   4:57 am  Mars-Jupiter: 0.6° N
    30  Mo   7:30 am  New Moon
Jun  1  We            Venus: 36.5° W

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

Sun and Moon Rising and Setting Events

     LU                  Ephemeris of Sky Events for Interlochen/TC
May, 2022    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Sun  1| 06:32a  08:47p  14:15 | 10:00p  05:20a |      Set  09:56p    1%|
|Mon  2| 06:31a  08:49p  14:17 | 10:01p  05:18a |      Set  11:02p    4%|
|Tue  3| 06:29a  08:50p  14:20 | 10:03p  05:17a |      Set  12:05a    9%|
|Wed  4| 06:28a  08:51p  14:23 | 10:04p  05:15a |      Set  01:03a   15%|
|Thu  5| 06:27a  08:52p  14:25 | 10:06p  05:13a |      Set  01:53a   23%|
|Fri  6| 06:25a  08:53p  14:28 | 10:08p  05:11a |      Set  02:35a   31%|
|Sat  7| 06:24a  08:55p  14:30 | 10:09p  05:10a |      Set  03:10a   40%|
+------+-----------------------+----------------+-----------------------+
|Sun  8| 06:23a  08:56p  14:33 | 10:11p  05:08a |F Qtr Set  03:39a   50%|
|Mon  9| 06:21a  08:57p  14:35 | 10:12p  05:06a |      Set  04:03a   60%|
|Tue 10| 06:20a  08:58p  14:38 | 10:14p  05:05a |      Set  04:25a   69%|
|Wed 11| 06:19a  08:59p  14:40 | 10:15p  05:03a |      Set  04:45a   79%|
|Thu 12| 06:18a  09:01p  14:43 | 10:17p  05:02a |      Set  05:06a   87%|
|Fri 13| 06:16a  09:02p  14:45 | 10:18p  05:00a |      Set  05:28a   93%|
|Sat 14| 06:15a  09:03p  14:47 | 10:20p  04:59a |      Set  05:53a   98%|
+------+-----------------------+----------------+-----------------------+
|Sun 15| 06:14a  09:04p  14:49 | 10:21p  04:57a |      Set  06:25a  100%|
|Mon 16| 06:13a  09:05p  14:52 | 10:23p  04:56a |Full  Rise 10:13p   99%|
|Tue 17| 06:12a  09:06p  14:54 | 10:24p  04:54a |      Rise 11:33p   95%|
|Wed 18| 06:11a  09:07p  14:56 | 10:26p  04:53a |      Rise 12:43a   89%|
|Thu 19| 06:10a  09:08p  14:58 | 10:27p  04:51a |      Rise 01:40a   80%|
|Fri 20| 06:09a  09:09p  15:00 | 10:29p  04:50a |      Rise 02:23a   70%|
|Sat 21| 06:08a  09:11p  15:02 | 10:30p  04:49a |      Rise 02:56a   59%|
+------+-----------------------+----------------+-----------------------+
|Sun 22| 06:07a  09:12p  15:04 | 10:32p  04:47a |L Qtr Rise 03:22a   48%|
|Mon 23| 06:06a  09:13p  15:06 | 10:33p  04:46a |      Rise 03:44a   37%|
|Tue 24| 06:05a  09:14p  15:08 | 10:34p  04:45a |      Rise 04:03a   27%|
|Wed 25| 06:05a  09:15p  15:10 | 10:36p  04:44a |      Rise 04:22a   18%|
|Thu 26| 06:04a  09:16p  15:11 | 10:37p  04:43a |      Rise 04:42a   11%|
|Fri 27| 06:03a  09:16p  15:13 | 10:38p  04:42a |      Rise 05:03a    6%|
|Sat 28| 06:02a  09:17p  15:15 | 10:39p  04:41a |      Rise 05:27a    2%|
+------+-----------------------+----------------+-----------------------+
|Sun 29| 06:02a  09:18p  15:16 | 10:41p  04:40a |      Rise 05:56a    0%|
|Mon 30| 06:01a  09:19p  15:18 | 10:42p  04:39a |New   Set  09:56p    0%|
|Tue 31| 06:00a  09:20p  15:19 | 10:43p  04:38a |      Set  10:56p    2%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

04/28/2022 – Ephemeris – The story of Arcas and Callisto

April 28, 2022 Comments off

This is Bob Moler with Ephemeris for Thursday, April 28th. Today the Sun will be up for 14 hours and 6 minutes, setting at 8:44, and it will rise tomorrow at 6:35. The Moon, 2 days before new, will rise at 6:16 tomorrow morning.

Appearing in the eastern sky at 10 p.m. tonight is the kite shaped constellation of Boötes the herdsman. The bright star Arcturus is at the bottom of the kite which is horizontal to the left, pointed to by the arc of the handle of the Big Dipper, higher in the east. The Big Dipper is the hind end of the constellation Ursa Major, the Great Bear. In one story, Boötes represents a young hunter named Arcas, son of Callisto, a beautiful young woman who had the misfortune of being loved by god Zeus. Zeus’ wife, Hera, found out about the affair, and since she couldn’t punish Zeus, turned the poor woman into a bear. Arcas, many years later, unaware of why his mother disappeared, was about to kill the bear when Zeus intervened and placed them both in the sky, where he continues to chase her across the sky nightly.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Arcas and Callisto

Boötes and Ursa Major aka Arcas chasing Callisto around the pole of the sky. Created using Stellarium.

Arcas and Callisto woodcut

Arcas about to slay the bear by the 17th century artist Baur. Source: University of Virginia Electronic Text Center

04/27/2022 – Ephemeris – Let’s search for the naked-eye planets for this week

April 27, 2022 Comments off

This is Bob Moler with Ephemeris for Wednesday, April 27th. Today the Sun will be up for 14 hours and 4 minutes, setting at 8:42, and it will rise tomorrow at 6:37. The Moon, 3 days before new, will rise at 5:56 tomorrow morning.

Let’s search for the naked-eye planets for this week. There is one bright planet in the evening sky. Mercury may be spotted around and after 9:30 this evening very low in the west-northwest and be visible for the next hour or so before it sets at 10:43 pm. After that, the planet action shifts to the morning sky. The other 4 naked-eye planets are there. By 5:45 am, the planets will be spread out low from the east to southeast with brilliant Venus closer than ever to Jupiter, lowest in the east. Dim Mars will be to the right and a bit above Venus, while brighter Saturn will be right and above Mars. Saturn will rise tomorrow at 4 am, with Mars following at 4:40. Venus will rise at 5:10 tomorrow morning, followed by Jupiter four minutes later.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

Mercury and bright winter stars in evening twilight

Mercury and bright winter stars in evening twilight at 9:30 tonight, or about 45 minutes after sunset tonight, April 27, 2022. It might take binoculars to spot the stars of Orion and Taurus, and Mercury itself, which is fading, becoming a crescent. Click on the image to enlarge it. Created using Stellarium.

The morning planet parade

The morning planet parade at 5:45 am or about 50 minutes before sunrise tomorrow, April 28, 2022. Venus will overtake Jupiter during the day, Saturday the 30th. Created using Stellarium.

Jupiter and Venus in binoculars

Jupiter and Venus in as they might be seen in binoculars, Saturday morning, April 30, 2022. The difference in brightness of Venus compared to Jupiter will be much greater than seen here. The planets will be about a half a degree apart, or about the width of the Moon. The image shows two satellites of Jupiter, Ganymede to the lower left of Jupiter and Callisto to the upper right. A third satellite, Io, is close to the upper right, within the enlarged Jupiter image. Europa is either behind the planet or in its shadow. Sunday morning, Jupiter will be on the other side of Venus, and a bit farther away. Created using Stellarium.

Telescopic views of Venus, Saturn and Jupiter

Views of Venus, Jupiter, and Saturn (north up) as they would be seen in a small telescope, with the same magnification, tomorrow morning at 5:45 am, April 28, 2022. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Venus 16.78″, 67.4% illuminated; Saturn 16.47″, its rings 38.35″; Jupiter 34.76″. Mars is not shown, its apparent diameter is 5.74″ and is 89.5% illuminated. Mercury, in the evening, has an apparent diameter of 8.05″, and it’s 35.6% illuminated. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

Planets and the Moon on a single night

The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on April 27, 2022. The night ends on the left with sunrise on the 28th. Notice that all the naked-eye planets except Mercury are in the morning sky now. Click on the image to enlarge it. Created using my LookingUp program.