06/06/2018 – Ephemeris – Our weekly look at the bright planets

June 6, 2018 Comments off

Ephemeris for Wednesday, June 6th. Today the Sun will be up for 15 hours and 27 minutes, setting at 9:25, and it will rise tomorrow at 5:57. The Moon, at last quarter today, will rise at 2:43 tomorrow morning.

It’s Wednesday again and time to look for and at the bright planets. Two of them are visible in the evening sky. The brilliant beacon of Venus will be visible in the western twilight from about 9:45 p.m. until it sets at 12:07 a.m. Jupiter will be in the south-southeast as it gets dark. Jupiter is only outshone by Venus and the Moon. And after Venus sets will have the night to itself as the brightest star-like object until it sets at 4:32 a.m. Binoculars will show it to be bigger than star-like in size flanked by little star-like moons. Saturn will rise at 10:45 p.m. in the east-southeast. Mars will rise at 12:50 a.m. and is now outshining Saturn, and will, in July and August even outshine Jupiter.

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

Addendum

Evening planets

Venus and Jupiter at 10:30 p.m. June 6, 2018. Click on image to enlarge. Created using Stellarium.

Jupiter and moons

Jupiter and moons at 10:30 p.m. June 6, 2018. Created using Cartes du Ciel (Sky Charts).

Morning planets

Morning planets and the Moon at 4:30 a.m. June 7, 2018. Click on image to enlarge. Created using Stellarium.

Binocular Moon

The moon as it might be seen in binoculars at 4:30 a.m. June 7, 2018. Created using Stellarium.

Telescopic morning planets

Saturn and Mars with the same magnification with an inset of Mars at higher magnification at 4:30 a.m. June 7, 2018. Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on June 6, 2018. The night ends on the left with sunrise on the 7th. Click on the image to enlarge. Created using my LookingUp program.

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06/05/2018 – Ephemeris – Green flash

June 5, 2018 Comments off

Ephemeris for Tuesday, June 5th. Today the Sun will be up for 15 hours and 25 minutes, setting at 9:24, and it will rise tomorrow at 5:58. The Moon, 1 day before last quarter, will rise at 2:16 tomorrow morning.

Now that it’s June and the season of summer is only two weeks away, thoughts run to heading out to the beach. One of the great pleasures of heading out to a Lake Michigan beach is seeing the sunset. And if the Sun sets on the cloudless horizon, a rare treat is to see the green flash. I’ve heard about it since my youth, but have seen it only once. I’ve seen the sunset many, though not a huge number of, times. The time I did, I was purposely looking for it. The green flash is when as the last part of the upper limb of the Sun disappears it suddenly turns green for a second, then it’s gone. So it’s easy to miss. The flash isn’t really brighter, but the top edge turns suddenly from reddish-orange to green as it disappears.

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

Addendum

Green flash in stages

The green flash recorded by Brocken Inaglory in January 2006 from Santa Cruz, CA. GNU Free Documentation License from the Green Flash Wikipedia page, which has more examples.

06/04/2018 – Ephemeris – Ariadne’s crown

June 4, 2018 Comments off

Ephemeris for Monday, June 4th. Today the Sun will be up for 15 hours and 24 minutes, setting at 9:23, and it will rise tomorrow at 5:58. The Moon, 2 days before last quarter, will rise at 1:47 tomorrow morning.

High in the southeast at 11 p.m. can be found a small but easily spotted constellation of Corona Borealis, the Northern Crown. It is located just east or left of the kite shaped constellation of Boötes, with its bright star Arcturus at the base. The Northern Crown is a semicircle of stars, like a tiara, with a brighter star Gemma at the bottom. Despite the obvious allusion of stars to diamonds and the sound of one of the star’s name, this is not a gem studded crown. Gemma means blossom, so Corona Borealis may represent a floral crown. According to Greek mythology it belonged to Princess Ariadne, daughter of King Minos of Crete. She was abandoned by Theseus, whom she helped out of the Labyrinth of the Minotaur.

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

Addendum

Corona Borealis finder chart

Animated Corona Borealis Finder Chart looking to the southeast at 10:30 p.m. June 4, 2018. Corona Borealis is  a small constellation, so I added its neighbors for context.  Click on the image to enlarge. Created using Stellarium and GIMP.

06/01/2018 – Ephemeris – Presentation tonight: Cosmic rays and the quiet Sun

June 1, 2018 Comments off

Ephemeris for Friday, June 1st. Today the Sun will be up for 15 hours and 21 minutes, setting at 9:21, and it will rise tomorrow at 5:59. The Moon, 3 days past full, will rise at 11:57 this evening.

Tonight at 8 p.m. at the June meeting of the Grand Traverse Astronomical Society at Northwestern Michigan College’s Rogers Observatory, Observatory Director Jerry Dobek will be giving a talk on how the Earth is receiving more cosmic rays from outside the solar system now that the Sun is in its quiet phase. Cosmic rays are not like x-rays or other forms of electromagnetic radiation. They are particles, bare nuclei of atoms, some pretty heavy. They are a danger to airline crews who fly over the north pole daily. After the meeting, at 9 p.m. the society will host a star party to view the planets Venus and Jupiter. The observatory is located south of Traverse City on Birmley Road between Garfield and Keystone roads.
43rd Anniversary of Ephemeris!

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

05/31/2018 – Ephemeris – Previewing June skies

May 31, 2018 Comments off

Ephemeris for Thursday, May 31st. Today the Sun will be up for 15 hours and 19 minutes, setting at 9:20, and it will rise tomorrow at 6:00. The Moon, 2 days past full, will rise at 11:10 this evening.

Let’s preview June skies. There will be a lot of Sun in June and very little night. The daylight hours will increase a bit from 15 hours and 21 minutes Tomorrow to 15 hours and 34 minutes on the 21st, retreating back to 15 hours 31 minutes at month’s end. The altitude of the sun above the southern horizon at local noon will hover around 68 to 69 degrees. Local noon, when the sun is actually due south will occur at about 1:43 p.m. Summer begins on the 21st at 6:07 a.m. when the sun reaches its farthest north. The actual amount of night-time will be quite short mostly due to the length of daylight, but also because twilight lasts much longer than average because the sun sets at a shallow angle. On the 21st there’s theoretically only 3 ½ hours of total darkness.

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

Addendum

June Evening Star Chart

June evening star chart

Star Chart for June 2018 (11 p.m. EDT June 15, 2018). 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). 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 4:30 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.

June Morning Star Chart

June Morning Star Chart

Star Chart for June 2018 mornings based on 4:30 a.m. June 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.

Twilight

Evening nautical twilight ends at 10:46 p.m. EDT on the 1st, increasing to 10:59 p.m. EDT on the 30th.
Evening astronomical twilight ends at 11:44 p.m. EDT on the 1st, increasing to 12:02 a.m. EDT on the 30th.
Morning astronomical twilight starts at 3:44 a.m. EDT on the 1st, and decreasing to 3:38 a.m. EDT on the 30th.
Morning nautical twilight starts at 4:42 a.m. EDT on the 1st, and decreasing to 4:40 a.m. EDT on the 30th.

NASA Calendar of Planetary Events

Date        Time    Event
Jun 01  Fr          Venus: 34.5° E
    01  Fr  3:09 am Moon South Dec.: 20.7° S
    02  Sa 12:34 pm Moon Apogee: 405300 km
    03  Su  7:58 am Moon-Mars: 3.5° S
    03  Su  8:39 am Moon Descending Node
    05  Tu  9:53 pm Mercury Superior Conj.
    06  We  2:32 pm Last Quarter
    07  Th 11:35 pm Venus-Pollux: 4.7° S
    13  We  3:43 pm New Moon
    14  Th  7:55 pm Moon Perigee: 359500 km
    14  Th  8:52 pm Moon North Dec.: 20.8° N
    16  Sa  9:13 am Moon-Venus: 2.3° N
    16  Sa  1:50 pm Moon Ascending Node
    16  Sa  3:38 pm Moon-Beehive: 1.5° N
    18  Mo  3:25 am Moon-Regulus: 1.7° S
    19  Tu 10:23 pm Venus-Beehive: 0.4° N
    20  We  6:51 am First Quarter
    21  Th  6:07 am Summer Solstice
    23  Sa  2:47 pm Moon-Jupiter: 4.6° S
    24  Su  5:35 pm Mercury-Pollux: 4.8° S
    27  We  8:25 am Saturn Opposition
    27  We 11:59 pm Moon-Saturn: 2° S
    28  Th 12:53 am Full Moon
    28  Th 10:30 am Moon South Dec.: 20.8° S
    29  Fr 10:43 pm Moon Apogee: 406100 km
    30  Sa 12:44 pm Moon Descending Node
Jul 01  Su          Venus: 40.7° 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 NMC Observatory
     June, 2018    Local time zone: EDT
     +-----------------------------------------------------------------------+
     | DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
     |      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
     +=======================================================================+
     |Fri  1| 06:00a  09:20p  15:20 | 10:43p  04:37a |      Rise 11:56p   90%|
     |Sat  2| 05:59a  09:21p  15:21 | 10:44p  04:36a |      Rise 12:38a   83%|
     +------+-----------------------+----------------+-----------------------+
     |Sun  3| 05:59a  09:22p  15:22 | 10:45p  04:36a |      Rise 01:14a   75%|
     |Mon  4| 05:59a  09:22p  15:23 | 10:46p  04:35a |      Rise 01:46a   67%|
     |Tue  5| 05:58a  09:23p  15:25 | 10:47p  04:34a |      Rise 02:15a   58%|
     |Wed  6| 05:58a  09:24p  15:26 | 10:48p  04:34a |L Qtr Rise 02:43a   48%|
     |Thu  7| 05:57a  09:25p  15:27 | 10:49p  04:33a |      Rise 03:10a   38%|
     |Fri  8| 05:57a  09:25p  15:28 | 10:50p  04:33a |      Rise 03:37a   28%|
     |Sat  9| 05:57a  09:26p  15:28 | 10:51p  04:32a |      Rise 04:06a   19%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 10| 05:57a  09:26p  15:29 | 10:52p  04:32a |      Rise 04:39a   11%|
     |Mon 11| 05:57a  09:27p  15:30 | 10:52p  04:31a |      Rise 05:17a    5%|
     |Tue 12| 05:56a  09:28p  15:31 | 10:53p  04:31a |      Rise 06:02a    1%|
     |Wed 13| 05:56a  09:28p  15:31 | 10:54p  04:31a |New   Set  09:20p    0%|
     |Thu 14| 05:56a  09:29p  15:32 | 10:54p  04:31a |      Set  10:26p    2%|
     |Fri 15| 05:56a  09:29p  15:32 | 10:55p  04:31a |      Set  11:25p    7%|
     |Sat 16| 05:56a  09:29p  15:33 | 10:55p  04:30a |      Set  12:14a   14%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 17| 05:56a  09:30p  15:33 | 10:56p  04:30a |      Set  12:55a   24%|
     |Mon 18| 05:56a  09:30p  15:33 | 10:56p  04:30a |      Set  01:30a   34%|
     |Tue 19| 05:56a  09:30p  15:33 | 10:56p  04:31a |      Set  02:01a   45%|
     |Wed 20| 05:57a  09:31p  15:33 | 10:57p  04:31a |F Qtr Set  02:29a   56%|
     |Thu 21| 05:57a  09:31p  15:33 | 10:57p  04:31a |      Set  02:57a   66%|
     |Fri 22| 05:57a  09:31p  15:33 | 10:57p  04:31a |      Set  03:24a   76%|
     |Sat 23| 05:57a  09:31p  15:33 | 10:57p  04:31a |      Set  03:54a   84%|
     +------+-----------------------+----------------+-----------------------+
     |Sun 24| 05:58a  09:31p  15:33 | 10:57p  04:32a |      Set  04:26a   90%|
     |Mon 25| 05:58a  09:31p  15:33 | 10:57p  04:32a |      Set  05:02a   95%|
     |Tue 26| 05:58a  09:31p  15:32 | 10:57p  04:33a |      Set  05:42a   99%|
     |Wed 27| 05:59a  09:31p  15:32 | 10:57p  04:33a |      Set  06:27a  100%|
     |Thu 28| 05:59a  09:31p  15:31 | 10:57p  04:34a |Full  Rise 09:54p   99%|
     |Fri 29| 06:00a  09:31p  15:31 | 10:56p  04:34a |      Rise 10:37p   97%|
     |Sat 30| 06:00a  09:31p  15:30 | 10:56p  04:35a |      Rise 11:15p   93%|
     +-----------------------------------------------------------------------+
     * Nautical Twilight
     ** Moonrise or moonset, whichever occurs between sunrise and sunset

 

05/30/2018 – Ephemeris – Its Wednesday, time to locate the bright planets

May 30, 2018 Comments off

Ephemeris for Wednesday, May 30th. Today the Sun will be up for 15 hours and 18 minutes, setting at 9:19, and it will rise tomorrow at 6:00. The Moon, 1 day past full, will rise at 10:18 this evening.

It’s Wednesday again and time to look for the bright planets. Two of them are in the evening sky. The brilliant beacon of Venus will be visible in the western twilight from about 9:40 p.m. until it sets at 12:04 a.m. Jupiter will be in the southeast as it gets dark. Jupiter is only outshone by Venus and the Moon. And after Venus sets will have the night to itself as the brightest star-like object until it sets at 5:02 a.m. Binoculars will show it to be bigger than star-like in size, that is it will appear as a tiny orb flanked by little star-like moons. Saturn will rise at 11:14 p.m. in the east-southeast. Mars will rise at 1:28 a.m. and is now outshining Saturn, and will, this summer even outshine Jupiter.

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

Addendum

Evening planets

Venus and Jupiter tonight May 30 2018. at 10 p.m. Click on image to enlarge. Created using Stellarium.

Telescopic Jupiter

Jupiter and moons in a telescope at 10 p.m., May 30, 2018 Created using Cartes du Ciel.

Io is in front of the planet. Its transit will begin at 10:37 p.m. EDT (2:37 UT May 31)
Io’s shadow will start to cross Jupiter at 11:07 p.m. EDT (3:07 UT May 31)
Io’s transit og Jupiter will end at 12:45 a.m. May 31 (4:45 UT)
Io’s Shadow will leave the face of Jupiter at 1:16 a.m. May 31 (5:16 UT)

Times above from https://www.projectpluto.com/jevent.htm

Morning planets

Morning planets Saturn and Mars plus the Moon at 5 a.m. May 31, 2018. Created using Stellarium.

Binocular Moon

The Moon as it might appear in binoculars at 5 a.m. May 31, 2018. Created using Stellarium.

Telescopic Mars and Saturn

Saturn and Mars with the same magnification with an inset of Mars at higher magnification at 5 a.m. May 31, 2018. Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on May 30, 2018. The night ends on the left with sunrise on the 31st. Click on the image to enlarge. Created using my LookingUp program.

 

05/29/2018 – Ephemeris – Jupiter, big and massive

May 29, 2018 Comments off

Ephemeris for Tuesday, May 29th. Today the Sun will be up for 15 hours and 16 minutes, setting at 9:18, and it will rise tomorrow at 6:01. The Moon, at full today, will rise at 9:21 this evening. | Jupiter is not only the largest planet, but the largest appearing planet pretty much all the time. Venus can look larger when it is a thin crescent about to or having just passed between the Earth and the Sun. Mars, because of its small actual size, that of half the Earth varies greatly in distance, and at its closest appears about half the size of Jupiter in telescopes. Jupiter’s great mass is the key to reasonable travel times of spacecraft to Saturn and beyond. A spacecraft sent to catch up to Jupiter will be accelerated with respect to the Sun into a faster trajectory to arrive at their destination sooner. New Horizon’s trip to Pluto would have taken 13 years, that’s 3 years longer without Jupiter’s gravity assist.

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

Addendum

New Horizons Trajectory

New Horizons trajectory as of last April showing the effect og Jupiter’s gravitational assist. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

Categories: Ephemeris Program, Jupiter