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02/01/2018 – Ephemeris – Previewing February skies

February 1, 2018 2 comments

Ephemeris for Thursday, February 1st. The Sun will rise at 8:01. It’ll be up for 9 hours and 49 minutes, setting at 5:51. The Moon, 1 day past full, will rise at 7:30 this evening.

Lets look ahead at our short month of February. It’s so short that this year it has no full moons. To make up for it both January and March have two. We’re in the depths of winter but the Sun is continuing its return to northern climes. This is reflected in the increase in daylight hours, from 9 hours 49 minutes today to 11 hours 7 minutes on the 28th. These times are for the Interlochen/Traverse City area. Daylight durations are slightly shorter in the northern part of our listening area and slightly longer to the south. As the month goes on the weather should generally warm and clear up. Venus is moving away from the Sun and will become more and more visible after sunset as the month wears on. Today Venus will set 24 minutes after the Sun. This will increase to an hour after the Sun.

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

Addenda

February Evening Sky Chart

February Evening Star Chart

Star Chart for February 2018 (9 p.m. EST February 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. 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. (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 9 p.m. and 6 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. For planet positions on dates other than the 15th, check the Wednesday planet posts on this blog.

February Morning Star Chart

February Morning Star Chart

Star Chart for February 2018 mornings based on 6 a.m. February 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.
  • The Summer Triangle is in red.

Twilight

Evening nautical twilight ends at 6:58 p.m. EST on the 1st, increasing to 7:31 p.m. EST on the 28th.
Evening astronomical twilight ends at 7:30 p.m. EST on the 1st, increasing to 8:04 p.m. EST on the 28th.
Morning astronomical twilight starts at 6:22 a.m. EST on the 1st, and decreasing to 5:45 a.m. EST on the 28th.
Morning nautical twilight starts at 6:56 a.m. EST on the 1st, and decreasing to 6:19 a.m. EST on the 28th.

NASA Calendar of Planetary Events

    Date    Time    Event
Feb 01 	Th	    Venus: 5.7° E
    01  Th  1:24 pm Moon-Regulus: 0.9° S
    07  We 10:54 am Last Quarter
    07  We  2:47 pm Moon-Jupiter: 4.7° S
    09  Fr 12:12 am Moon-Mars: 4.8° S
    11  Su  9:16 am Moon Apogee: 405700 km
    11  Su  9:46 am Moon-Saturn: 2.7° S
    11  Su 11:40 am Mars-Antares: 5.1° N
    11  Su  6:21 pm Moon South Dec.: 20° S
    14  We  4:11 pm Moon Descending Node
    15  Th  3:52 pm Partial Solar Eclipse - S. America, Antarctica
    15  Th  4:05 pm New Moon
    17  Sa  7:08 am Mercury Superior Conj.
    23  Fr  3:09 am First Quarter
    23  Fr 12:07 pm Moon-Aldebaran: 0.7° S
    25  Su  3:07 pm Moon North Dec.: 20.1° N
    27  Tu  9:48 pm Moon Perigee: 363900 km
    27  Tu 12:28 pm Moon-Beehive: 2.3° N
    28  We 12:03 am Moon Ascending Node
Mar 01  Th          Venus: 12.4° 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
     February, 2018    Local time zone: EST
     +-----------------------------------------------------------------------+
     | DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
     |      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
     +=======================================================================+
     |Thu  1| 08:01a  05:51p  09:49 | 06:57p  06:55a |      Rise 07:30p   97%|
     |Fri  2| 08:00a  05:52p  09:52 | 06:58p  06:54a |      Rise 08:43p   92%|
     |Sat  3| 07:59a  05:54p  09:54 | 07:00p  06:53a |      Rise 09:53p   85%|
     +------+-----------------------+----------------+-----------------------+
     |Sun  4| 07:58a  05:55p  09:57 | 07:01p  06:52a |      Rise 11:01p   76%|
     |Mon  5| 07:57a  05:57p  10:00 | 07:02p  06:51a |      Rise 12:06a   66%|
     |Tue  6| 07:55a  05:58p  10:02 | 07:04p  06:50a |      Rise 01:09a   57%|
     |Wed  7| 07:54a  06:00p  10:05 | 07:05p  06:49a |L Qtr Rise 02:10a   47%|
     |Thu  8| 07:53a  06:01p  10:08 | 07:06p  06:48a |      Rise 03:09a   37%|
     |Fri  9| 07:51a  06:02p  10:11 | 07:07p  06:46a |      Rise 04:05a   28%|
     |Sat 10| 07:50a  06:04p  10:13 | 07:09p  06:45a |      Rise 04:57a   20%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 11| 07:48a  06:05p  10:16 | 07:10p  06:44a |      Rise 05:45a   13%|
     |Mon 12| 07:47a  06:07p  10:19 | 07:11p  06:42a |      Rise 06:29a    8%|
     |Tue 13| 07:46a  06:08p  10:22 | 07:13p  06:41a |      Rise 07:07a    3%|
     |Wed 14| 07:44a  06:09p  10:25 | 07:14p  06:40a |      Rise 07:42a    1%|
     |Thu 15| 07:43a  06:11p  10:28 | 07:15p  06:38a |New   Set  06:07p    0%|
     |Fri 16| 07:41a  06:12p  10:31 | 07:16p  06:37a |      Set  07:09p    1%|
     |Sat 17| 07:40a  06:14p  10:34 | 07:18p  06:36a |      Set  08:13p    5%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 18| 07:38a  06:15p  10:37 | 07:19p  06:34a |      Set  09:17p   10%|
     |Mon 19| 07:36a  06:16p  10:40 | 07:20p  06:33a |      Set  10:23p   17%|
     |Tue 20| 07:35a  06:18p  10:43 | 07:22p  06:31a |      Set  11:29p   25%|
     |Wed 21| 07:33a  06:19p  10:46 | 07:23p  06:30a |      Set  12:38a   35%|
     |Thu 22| 07:32a  06:21p  10:49 | 07:24p  06:28a |      Set  01:46a   46%|
     |Fri 23| 07:30a  06:22p  10:52 | 07:25p  06:27a |F Qtr Set  02:54a   57%|
     |Sat 24| 07:28a  06:23p  10:55 | 07:27p  06:25a |      Set  04:00a   69%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 25| 07:27a  06:25p  10:58 | 07:28p  06:23a |      Set  04:59a   79%|
     |Mon 26| 07:25a  06:26p  11:01 | 07:29p  06:22a |      Set  05:52a   88%|
     |Tue 27| 07:23a  06:27p  11:04 | 07:31p  06:20a |      Set  06:38a   94%|
     |Wed 28| 07:22a  06:29p  11:07 | 07:32p  06:18a |      Set  07:17a   99%|
     +-----------------------------------------------------------------------+
     * Nautical Twilight
     ** Moonrise or moonset, whichever occurs between sunset and sunrise

 

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12/22/2017 – Ephemeris – The joining of a god and goddess, a second possibility of the Star of Bethlehem

December 22, 2017 1 comment

Ephemeris for Friday, December 22nd. The Sun will rise at 8:16. It’ll be up for 8 hours and 48 minutes, setting at 5:05. The Moon, half way from new to first quarter, will set at 9:21 this evening.

On Tuesday I talked about what I said was one of two possible physical explanations for the Star of Bethlehem. Here is the second. On August 13th of 3 BC Jupiter and Venus briefly merged in the pre-dawn skies against the constellation of Leo the lion. A month later Jupiter was in conjunction with Regulus the bright star in Leo, the little king star. Then 9 months later, after sunset on June 16th of 2 BC the two planets again joined as one in Leo. The king of the planets twice mating with Venus as Ishtar, the Babylonian goddess of fertility, against the constellation of the lion signifying Judah in Genesis? One might find meaning in all that, especially the Magi, who were Zoroastrian astrologer-priests from Persia.

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

Addendum

Jupiter-Venus conjunction of August 3, 3 BC.

Animation of the Jupiter-Venus conjunction of August 13, 3 BC. in the morning twilight. Created using Stellarium.

June of 2 BC just after sunset Jupiter and Venus again cross paths.

June 16, 2 BC just after sunset Jupiter and Venus again cross paths, at one point too close to be separated with the naked eye. Created using Stellarium.

 

07/04/2017 – Ephemeris – Happy birthday America! Tomorrow morning Venus will appear near the Pleiades

July 4, 2017 1 comment

Ephemeris for Independence Day, Tuesday, July 4th. Today the Sun will be up for 15 hours and 27 minutes, setting at 9:30, and it will rise tomorrow at 6:03. The Moon, 4 days past first quarter, will set at 3:46 tomorrow morning.

This is the 241st anniversary of the signing of the Declaration of Independence. Venus is our morning star now, and back in 1776 it too was a morning planet, but a lot closer to the rising Sun, and harder to spot.

Tonight Venus will pass south of the famous Pleiades star cluster, so that tomorrow morning at about 4:30 it will be dark enough to see the Pleiades above and left of our brilliant Morning Star.

Planets to us appear as stars to the naked eye due to their distance, though they are close enough to appear as disks in small telescopes. Very few of the largest telescopes can ever see the disk of a star, other than the Sun,, and only if that star is really huge, like Betelgeuse in the winter constellation of Orion.

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

Addendum

Venus and the Pleiades

The eastern sky at 5 a.m. July 5, 2017 with the Pleiades above and left of Venus. Created using Stellarium.

We’ll be seeing the Pleiades in the evening sky in four months when summer is a memory.

July 4, 1776

The morning sky to the east and Venus about 20 minutes before sunrise that auspicious morning July 4, 1776 from Philadelphia. Created using Stellarium.

Excuse the fact that the landscape is the same in both images.

Betelgeuse disk

This is the disk of the star Betelgeuse in Orion. It is not an image from an optical telescope of an image created in submillimeter microwaves by the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Credit: ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella.

Betelgeuse, though it is 600 light years away has a radius of slightly more than the orbit of Jupiter.  The bump on the left side of the image may be a plume of gas erupting from the star.

06/05/2017 – Ephemeris – Why Venus is low in the eastern sky

June 5, 2017 1 comment

Ephemeris for Monday, June 5th. Today the Sun will be up for 15 hours and 25 minutes, setting at 9:23, and it will rise tomorrow at 5:58. The Moon, half way from first quarter to full, will set at 4:40 tomorrow morning.

Saturday the planet Venus was at greatest western elongation from the Sun, That is it is the farthest west it will appear from the Sun. It’s still not very high in our sky. However for those in the southern hemisphere Venus will appear very high in the east. There is a rule about this: Planets which are east of the Sun, like Mars is now are easiest seen on spring evenings. Planets which are west of the Sun, like Venus is now are easiest seen on autumn mornings. Since the southern hemisphere has the opposite seasons as the north, this is their autumn, and morning planets are easiest seen. This is especially true for Mercury, which is even closer to the Sun than Venus. Generally it’s only seen when it appears on spring evenings and autumn mornings.

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

Addendum

Low morning planets

Venus’ low morning appearance is due to the fact that on spring mornings the ecliptic (red line path of the Sun in the sky and nearly that of the planets) lies low to the horizon. Created using Stellarium.

04/13/2017 – Ephemeris – Venus is in the morning sky

April 13, 2017 Comments off

Ephemeris for Thursday, April 13th.  The Sun will rise at 7:01.  It’ll be up for 13 hours and 23 minutes, setting at 8:25.  The Moon, 2 days past full, will rise at 10:52 this evening.

Venus is beginning to make its morning appearance now, rising just before 6 a.m.  It’s north and west of the Sun, but it’s path away from the Sun is at a low angle to the horizon.  Venus is now in its crescent phase, which is getting fatter, as it separates from the Sun.  It is also getting smaller in our telescopes as it recedes from us. Venus has no natural satellites,  however it currently has a small robotic one.  It is Japan’s Akatsuki or Dawn spacecraft.  Launched in 2010, it failed to fire its rocket engine for the entire time needed to drop it into orbit of Venus.  The engineers devised a plan to chase Venus for 5 years and gently maneuver the spacecraft into orbit using only its attitude thrusters.  This they accomplished in December of 2015.

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

Addendum

Telescopic Venus

Telescopic Venus as created with Stellarium for early morning April 14, 2017. Stellarium is coloring Venus as it would be colored low in the sky.

Akatsuki

Artists drawing of Akatsuki orbiting Venus. Credit Japanese Institute of Space and Astronautical Science (ISAS)

Localized Vortex

A localized vortex in the clouds of Venus captured by Akatsuki. Credit ISAS.

Venus cloud animation.

An animation of the clouds rotating on Venus’ night side by Akatsuki. Credit ISAS

Categories: Ephemeris Program, Venus Tags:

02/23/2017 – Ephemeris – The Evening Star’s days are numbered

February 23, 2017 Comments off

Ephemeris for Thursday, February 23rd.  The Sun will rise at 7:29.  It’ll be up for 10 hours and 53 minutes, setting at 6:22.  The Moon, 3 days before new, will rise at 6:15 tomorrow morning.

The brilliant Evening Star, the planet Venus entered our evening sky last June.  It seemed it took forever to move far enough away from the Sun to be easily seen after sunset.  The summer and autumn time is a hard time to spot a planet near the Sun after sunset, because they appear more to the left of the Sun than above it.  Now, in late winter Venus is high in the west after sunset.  But that won’t last.  It’s nearly 9 month’s reign as the Evening Star are about up. In 27 days it will be gone, out of the evening sky as it rapidly passes between the Earth and the Sun.  Venus will be only 26 million miles (42 million km) from the Earth.  Back is 2012 it crossed the face of the sun at conjunction, On March 25th it will be 16 Sun diameters north of our star.

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

Addendum

Venus' orbit in the evening sky.

Venus and Mars showing Venus’ orbit showing how far north it will get above the ecliptic, the yellow line, which is the path of the Sun. Created using Stellarium.

 

Categories: Ephemeris Program, Venus Tags:

01/12/17 – Ephemeris – Venus is at greatest eastern elongation today

January 12, 2017 2 comments

Ephemeris for Thursday, January 12th.  The Sun will rise at 8:17.  It’ll be up for 9 hours and 7 minutes, setting at 5:25.  The Moon, at full today, will rise at 6:04 this evening.

Today, around 8 a.m. the planet Venus will reach its greatest eastern elongation from the Sun. What that means in simple terms is that Venus will appear as far east of the Sun that it can get.  The angle between it and the Sun will be 47.1 degrees.  Venus, like Mercury orbits the Sun inside the Earth’s orbit, so is always seen close to the Sun.  In telescopes Venus will look like a tiny half illuminated orb, like a first quarter Moon.  That’s for the same reason.  The Sun is illuminating half of the side we can see.  Venus is  moving directly toward us now, at a distance of 63 million miles (102 million km).    As Venus approaches us, it will grow in size in telescopes, becoming larger in appearance than Jupiter the largest planet.  It will leave the evening sky, passing between the Earth and the Sun, only 26 million miles away on March 25th.

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

Addendum

Venus in our sky

Venus at 5:30 p.m. January 12, 2017 also displaying its orbit. Created using Stellarium.

Telescopic Venus

Venus in a telescope showing it half illuminated at greatest eastern elongation. Created using Stellarium.

There’s an odd phase effect called the “Venus Dichotomy” where at the instant of greatest elongation that Venus’ phase is not exactly half illuminated.  Half phase may differ by several hours.  The actual time of greatest eastern elongation according to NASA’s SKYCAL Calendar at https://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html is January 12 at 7:59 a.m. EST or 12:59 UT.

Inner solar system

Inner solar system showing the relationship of Venus and the Earth. At greatest elongation The angle between Venus-Sun line and Venus-Earth line is 90 degrees. which is why Venus shows as half illuminated. Created using the application NASA’s Eyes.

Note that the chart above also shows NASA’s inner solar system missions.  To download the app, created by the Jet Propulsion Laboratory (JPL), go to https://eyes.nasa.gov/.  Use it to follow the progress of NASA solar system missions.