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Posts Tagged ‘Gemini’

02/16/2017 – Ephemeris – The Winter Circle

February 16, 2017 Comments off

Ephemeris for Thursday, February 16th.  The Sun will rise at 7:40.  It’ll be up for 10 hours and 32 minutes, setting at 6:12.  The Moon, 2 days before last quarter, will rise at 12:17 tomorrow morning.

The winter skies are blessed with more first magnitude stars than any other season.  These are the twenty-one brightest stars in the sky.  Six of these stars lie in a large circle centered on the seventh.  This circle is up all evening now that we are in the heart of winter.  Starting high overhead is Capella in Auriga the charioteer.  Moving clockwise, we come to Aldebaran in the face of Taurus the Bull.  Then down to Orion’s knee we find Rigel.  Down and left is the brightest star of all Sirius the Dog Star in Canis Major Orion’s large hunting dog, lowest of these stars in the south.  Moving up and left there is Procyon in Canis Minor, Then above it is Pollux in Gemini the twins.  All are centered on Betelgeuse in Orion.

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

Addendum

The Winter Circle of 1st magnitude stars

The Winter Circle of 1st magnitude stars. Created using my LookingUp program.

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04/04/2016 – Ephemeris – Hydra the water snake will slither along the southern horizon this spring

April 4, 2016 Comments off

Ephemeris for Monday, April 4th.  The Sun will rise at 7:17.  It’ll be up for 12 hours and 57 minutes, setting at 8:14.   The Moon, 3 days before new, will rise at 6:18 tomorrow morning.

In the southeastern evening sky can be found the constellation of Hydra the water snake.  Unlike the monster of the same name this Hydra has but one head, which is its most distinctive part.  At 10 p.m. look to the south-southeast.  The head of Hydra is located below a line from the constellation Leo the Lion in the southeast and Gemini high in the southwest.  It is directly below Cancer the crab in the south.  Hydra’s head is a small but distinctive group of 6 stars that make a loop and the snake’s slightly drooping head.  The rest of Hydra wends its way to the southeastern horizon, and eventually ends near the late spring constellation Libra the scales.  Over the next few months the rest of Hydra will slither across the southern horizon.

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

Addendum

Hyrra

Hydra the water snake raising its head below Cancer at 10 p.m. April 4, 2016. Created using Stellarium.

02/18/2016 – Ephemeris – Castor and Pollux

February 18, 2016 Comments off

Ephemeris for Thursday, February 18th.  The Sun will rise at 7:39.  It’ll be up for 10 hours and 35 minutes, setting at 6:14.   The Moon, 3 days past first quarter, will set at 5:28 tomorrow morning.

The star Pollux is at the head of the same named brother of Gemini the twins.  Castor is the  slightly dimmer star right above it.  Pollux is about 34 light years away.  It’s twice as massive as the Sun, and has run out of hydrogen in its core and is in the process of evolving into a red giant star.  One planet, twice as massive as Jupiter has been detected around it.  Castor is at 51 light years away.  There are 6 stars in its system.  The brightest three are visible in telescopes.  Each is a spectroscopic binary, meaning that the companion stars are detected by the Doppler shifts of the lines in their spectra as the stars orbit each other.   The Doppler shift is just one of the many pieces of information revealed by the spectroscope.

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

Addendum

Castor and Pollux

Castro and Pollux with the bright Moon and other bright stars and constellations of winter. 9 p.m. February 18, 2016. Created using Stellarium.

Castor star system

The Castor star system exploded in this JPL/NASA infographic.

The entire infographic is here.

Categories: Ephemeris Program, stars Tags: , ,

01/11/2016 – Ephemeris – Gemini, the half-brothers that are twins

January 11, 2016 Comments off

Ephemeris for Monday, January 11th.  The Sun will rise at 8:18.  It’ll be up for 9 hours and 4 minutes, setting at 5:22.   The Moon, 2 days past new, will set at 7:36 this evening.

Before the Moon brightens the evening sky, lets look at another of the winter constellations.  The constellation Gemini, the Twins is visible high in the east-southeast, above and left of Orion the hunter at 9 p.m.  The namesake stars of the two lads, will be at the left end of Gemini, vertically aligned.  Castor is on top, while Pollux is below.  From them come two lines of stars extending toward Orion that outline the two.  In Greek mythology the lads were half brothers, Castor was fathered by a mere mortal, while Pollux was fathered by Zeus in the famous Leda and the swan affair, but were born together.  When Castor was killed during the quest for the Golden Fleece, Pollux pleaded with Zeus to let him die also, so both appear together in the sky forever.

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

Addendum

Gemini

Gemini revealed by animation. Created using Stellarium and GIMP.

12/10/2015 – Ephemeris – What’s a charioteer doing holding goats?

December 10, 2015 Comments off

Ephemeris for Thursday, December 10th.  The Sun will rise at 8:08.  It’ll be up for 8 hours and 53 minutes, setting at 5:02.   The Moon, 1 day before new, will rise at 7:59 tomorrow morning.

Rising now more than half way up the sky in the east at 9 p.m. will be the bright star Capella and its pentagonal constellation Auriga the Charioteer.  Auriga appears to be hunched down sideways in the sky in his chariot carrying 4 goats.  Capella is the mother goat, and a slim triangle of stars near her are her kids.  Perhaps the kids in the chariot were such a distraction that he crashed.  So maybe the gods placed them in the sky as a warning.   In fact that triangle is an asterism widely known as the Kids.  The Milky Way runs through Auriga and it is the home of several star clusters that appear as fuzzy spots in binoculars.  Capella for us in northern Michigan never sets.  It is a winter star that can be seen year round.  It’s disconcerting to spot it scraping the northern horizon in July.

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

Addendum

Auriga

Auriga and neighboring constellations for 9 p.m. December 10, 2015. Created using Stellarium and GIMP.

02/16/2015 – Ephemeris – The Winter Circle

February 16, 2015 Comments off

Feb 16.  This is Bob Moler with Ephemeris for President’s Day, Monday, February 16th.  The sun will rise at 7:42.  It’ll be up for 10 hours and 30 minutes, setting at 6:12.   The moon, 2 days before new, will rise at 6:25 tomorrow morning.

The winter skies are blessed with more first magnitude stars than any other season.  That’s a full one-third of the total are seen is a relatively small area.  Six of these stars lie in a large circle centered on the seventh.  This circle is up at 9 p.m.  Starting high overhead is Capella in Auriga the charioteer.  Moving down clockwise is Aldebaran in the face of Taurus the Bull.  Then down to Orion’s knee we find Rigel.  Down and left is the brightest star of all Sirius the Dog Star in Canis Major, lowest of these stars in the south-southeast.  Moving up and left is Procyon in Canis Minor, Above Procyon is Pollux in Gemini the twins.  All these are centered on Betelgeuse the bright red star in Orion’s shoulder.

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

Addendum

The Winter Circle of 1st magnitude stars

The Winter Circle of 1st magnitude stars

02/13/2015 – Ephemeris – The stars Castor and Pollux

February 13, 2015 Comments off

Ephemeris for Friday, February 13th.  The sun will rise at 7:46.  It’ll be up for 10 hours and 21 minutes, setting at 6:08.   The moon, 2 days past last quarter, will rise at 3:51 tomorrow morning.

At 9 p.m. the constellation of Gemini the twins will be seen high in the southeast.  The namesake stars of the two lads are the two bright stars at the top of the constellation.  Pollux the pugilist, or boxer, is the lower of the two, while Castor, the horseman, is the other star, or rather a six star system.  In telescopes two close stars may be seen each is a spectroscopic binary, meaning the lines of two stars can be seen in the spectrum.  A faint nearby spectroscopic binary also belongs.    Pollux, though a single star, does have at least one planet, one over twice the mass of Jupiter orbiting the star at a distance somewhat greater than Mars is from the sun.  Pollux is 34 light years away while Castor is 50 light years away.  Not too far away as stars go.

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

Addendum

Gemini with the stars Castor and Pollux

Gemini with the stars Castor and Pollux. Created using Stellarium.

 

Categories: Ephemeris Program, stars Tags: , ,