Archive
11/14/2017 – Ephemeris – The constellation of Perseus the hero
Ephemeris for Tuesday, November 14th. The Sun will rise at 7:38. It’ll be up for 9 hours and 37 minutes, setting at 5:15. The Moon, half way from last quarter to new, will rise at 4:29 tomorrow morning.
About half way up from the east northeastern horizon to the zenith at 9 p.m. and below the letter W shaped constellation of Cassiopeia the queen is Perseus the hero. It’s kind of an odd shape for a hero, To me it looks like a maybe the cartoon road runner running along the road. To those who’s imagination doesn’t run to Loony Tunes, its shape is also like the Greek letter pi. It’s two brightest stars are Mirfak and Algol the demon star. Look at the area around Mirfak with binoculars and you will see a large group of stars just below naked eye visibility. It’s called the Alpha Persei association. That because Mirfak is Alpha Persei. The group is about 557 light years away, which means, is quite close, but farther away than the Pleiades, below and right of them.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Perseus with Cassiopeia and Andromeda in the northeast at 9 p.m. Created using Stellarium and GIMP.
10/30/2017 – Ephemeris – Halloween preview: The Ghoul Star
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
Perseus, Cassiopeia, Andromeda with Algol finder animation for Autumn evenings. Created using Stellarium and GIMP.
Animation of an eclipsing binary star like Algol. Credit: Wikimedia Commons h/t Earth and Sky
10/31/2016 – Ephemeris – What’s a Halloween sky without the Ghoul Star
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 8:30 p.m. on Halloween. Created using Stellarium and GIMP.
Animation of an eclipsing binary star like Algol. Credit: Wikimedia Commons h/t Earth and Sky
10/30/2015 – Ephemeris – The spookiest star
Ephemeris for Friday, October 30th. The Sun will rise at 8:17. It’ll be up for 10 hours and 16 minutes, setting at 6:34. The Moon, 3 days past full, will rise at 9:33 this evening.
Tomorrow night is the spookiest night of the year, so lets look at 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 winked this morning and it will again centered on 11:45 p.m. Sunday night.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Algol at 7:30 p.m. on Halloween, in a modern portrayal. Created using Stellarium.
Animation of an eclipsing binary star like Algol. Credit: Wikimedia Commons h/t Earth and Sky
10/31/2014 – Ephemeris – The spookiest star
Ephemeris for Halloween, Friday, October 31st. The sun will rise at 8:18. It’ll be up for 10 hours and 13 minutes, setting at 6:32. The moon, 1 day past first quarter, will set at 1:59 tomorrow morning.
Not all the ghosts and goblins out Sunday will be children. One will be 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 two days 21 hours, because it is two stars that eclipse each other. Her next wink will be 10 p.m. Sunday night.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Perseus and the head of Medusa from the 1690 Uranographia by Johannes Hevelius. Image found with the article on Algol in Wikipedia.
Celestial globes of the day showed the celestial sphere from the outside, so the constellations appeared reversed. The star atlases of the day kept the trend. I reversed the image to correspond with the actual sky.
Algol at 7:30 p.m. on Halloween, in a modern portrayal. Created using Stellarium.
Update
Animation of an eclipsing binary star like Algol. Credit: Wikimedia Commons. H/T EarthSky
Here’s a link to EarthSky’s post on Algol.
10/31/2012 – Epmeneris – The Ghoul Star
Ephemeris for Halloween, Wednesday, October 31st. The sun will rise at 8:19. It’ll be up for 10 hours and 12 minutes, setting at 6:32. The moon, 2 days past full, will rise at 7:37 this evening.
Not all the ghosts and goblins out tonight will be children. One will be 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 a mausoleum or more ominously ‘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 very close stars that eclipse each other in that period.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The constellation Perseus in the northeast at 9 p.m. on October 31, 2012. Created using Stellarium.
Perseus and the head of Medusa from the 1690 Uranographia by Johannes Hevelius. Image found with the article on Algol in Wikipedia.
Note that this is a mirror image. The star charts in the 17th century were based on celestial globes, which represented the constellations as seen from the outside of the celestial sphere instead of from the inside. I reversed the image to match Perseus as we see him.
10/31/11 – Ephemeris – The spookiest star
Halloween, Monday, October 31st. The sun will rise at 8:18. It’ll be up for 10 hours and 14 minutes, setting at 6:33. The moon, 2 days before first quarter, will set at 11:04 this evening.
On the spookiest night of the year, lets look at 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 will be winking this evening, dimmer than usual. My ephemeris blog has a finder chart. Just Google Bob Moler.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Bob Moler's Ephemeris Blog 