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Posts Tagged ‘Medusa’

10/30/2017 – Ephemeris – Halloween preview: The Ghoul Star

October 30, 2017 1 comment

Ephemeris for Monday, October 30th. The Sun will rise at 8:17. It’ll be up for 10 hours and 15 minutes, setting at 6:33. The Moon, 3 days past first quarter, will set at 3:50 tomorrow morning.

Tomorrow night is the spookiest night of the year, so lets preview the spookiest star of all. It’s Algol, from Ghoul Star or Demon Star. The Chinese had a name for it that meant ‘piled up corpses’. It’s the second brightest star in the constellation Perseus the hero, rising in the northeast this evening. The star is located where artists have drawn the severed head of Medusa, whom he had slain. Medusa was so ugly that she turned all who gazed upon her to stone. Algol is her still glittering eye. Astronomers finally found out what was wrong with Algol. It does a slow 6 hour wink every two days 21 hours, because it is two stars that eclipse each other. It began to dip this morning just before sunrise and it will again centered on 11:41 p.m. Friday night.

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

Addendum

Algol Finder

Perseus, Cassiopeia, Andromeda with Algol finder animation for Autumn evenings. Created using Stellarium and GIMP.

Eclipsing Binary Star

Animation of an eclipsing binary star like Algol. Credit: Wikimedia Commons h/t Earth and Sky

 

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10/31/2016 – Ephemeris – What’s a Halloween sky without the Ghoul Star

October 31, 2016 Comments off

Ephemeris for Halloween, Monday, October 31st.  The Sun will rise at 8:20.  It’ll be up for 10 hours and 12 minutes, setting at 6:32.  The Moon, 1 day past new, will set at 7:28 this evening.

Not all the ghosts and goblins out tonight will be children.  One is out every night, because it’s a star.  Its name is Algol, from the Arabic for Ghoul Star or Demon Star.  The Chinese had a name for it that meant ‘piled up corpses’.  It’s the second brightest star in the constellation Perseus the hero, rising in the northeast this evening.  The star is located where artists have drawn the severed head of Medusa, whom he had slain.  Medusa was so ugly that she turned all who gazed upon her to stone.  Algol is her still glittering eye.  Astronomers finally found out what was wrong with Algol.  It does a slow 6 hour wink every 2 days 21 hours because it is two very close stars that eclipse each other in that period.  It did so this morning at 5:53 a.m.

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

Addendum

To run an app to calculate times for the minima of Algol click here:  http://www.skyandtelescope.com/observing/celestial-objects-to-watch/the-minima-of-algol/ courtesy of Sky and Telescope Magazine.

Perseus with Cassiopeia and Andromeda in the northeast at 9 p.m. October 20, 2016. Created using Stellarium and GIMP

Perseus with Cassiopeia and Andromeda in the northeast at 8:30 p.m. on Halloween.  Created using Stellarium and GIMP.

Eclipsing Binary Star

Animation of an eclipsing binary star like Algol. Credit: Wikimedia Commons h/t Earth and Sky

 

 

 

09/03/2013 – Ephemeris – The constellation of Pegasus the flying horse

September 3, 2013 Comments off

Ephemeris for Tuesday, September 3rd.  The sun will rise at 7:07.  It’ll be up for 13 hours and 7 minutes, setting at 8:14.   The moon, 2 days before new, will rise at 6:20 tomorrow morning.

A reminder that the end of summer is approaching is located in the east around 10 p.m. It’s one of the great autumn constellations: Pegasus the flying horse of Greek myth.  Its most visible feature is a large square of four stars, now standing on one corner.  This feature, called the Great Square of Pegasus, represents the front part of the horse’s body.  The horse is quite aerobatic, because it is seen flying upside down.  Remembering that fact, the neck and head is a bent line of stars emanating from the right corner star of the square.  Its front legs can be seen in a gallop extending to the upper right from the top star of the square.  In Mythology Pegasus was born of the blood of Medusa, decapitated by the hero Perseus, seen as a constellation rising in the northeast.

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

Addendum

Pegasus

Pegasus image in the stars at 10 p.m. September 3, 2013. Created using Stellarium. Drawing by Johan Meuris.