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11/25/2015 – Ephemeris – The occultation of Aldebaran is tomorrow morning!
Ephemeris for Wednesday, November 25th. The Sun will rise at 7:52. It’ll be up for 9 hours and 14 minutes, setting at 5:06. The Moon, at full today, will rise at 5:26 this evening.
Tomorrow morning between about 5:38 and 6:29 a.m. the Moon will pass in front of the bright star Aldebaran. The event is called an occultation. Aldebaran is the bright reddish star in the V-shaped face of the constellation Taurus the bull, which is seen in the sky charging Orion the hunter in the evening sky now. By the time of this event, they will have moved into the west. Aldebaran, though bright, doesn’t hold a candle to the nearly full Moon. I know that a holiday is a good day to sleep in, unless you are getting an early start on preparing the Thanksgiving feast. In any case the earlier you get out to spot Aldebaran the easier it will be to find in the Moon’s glare. Check out my posts on bobmoler.wordpress.com for more information.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Here’s the Moon hiding Aldebaran in its glare at 5:30 a.m. tomorrow morning November 26, 2015. Created using Stellarium.
An occultation animation starting at 5:19 a.m. EST showing 10 minute intervals. Computer generated graphics cannot produce a point star. Aldebaran will wink out and back in an instant. Created using Cartes du Ciel (Sky Charts) and GIMP.
11/23/2015 – Ephemeris – An occultation of Aldebaran by the Moon will be visible to much of the northern US Thursday morning
Ephemeris for Monday, November 23rd. The Sun will rise at 7:49. It’ll be up for 9 hours and 18 minutes, setting at 5:08. The Moon, 2 days before full, will set at 5:58 tomorrow morning.
Thursday morning, Thanksgiving Day here in the US, the Moon will occult or pass in front of the bright star Aldebaran for the northern half of the United States, and Canada. I have a special post on my blog dated yesterday, November 22nd. It’s titled Aldebaran Occultation November 26, 2015 from Northern Michigan (click here) with all the details. My blog is bobmoler.wordpress.com, or do an Internet search for Bob Moler, That’s Moler spelled M-O-L-E-R, no extra letters. Aldebaran is the bright orange star in the face of the constellation Taurus the bull. You will need at least a pair of binoculars to pick out Aldebaran next to the Moon. Aldebaran will disappear at about 5:38 a.m. and reappear about 6:29 a.m. for Interlochen and Traverse City.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location. The November 22 post has instructions on how to calculate the occultation times for your location, and has a map to see if you can view the occultation at all.
Addendum
An occultation animation starting at 5:19 a.m. EST showing 10 minute intervals. Not that the computer generated graphics cannot produce a point star. Aldebaran will wink out and back in an instant. Created using Cartes du Ciel (Sky Charts) and GIMP.
11/20/2015 – Ephemeris – Finding the bright stars of November
Ephemeris for Friday, November 20th. The Sun will rise at 7:46. It’ll be up for 9 hours and 24 minutes, setting at 5:10. The Moon, 1 day past first quarter, will set at 2:17 tomorrow morning.
The Moon is beginning to brighten up the sky making constellation spotting somewhat difficult, so I thought we’d look for the brightest stars. High in the west are the three stars of the Summer Triangle. At the bottom in the southwest is Altair, the first of these to set. A bit north of west the brightest, Vega. Highest in the west is Deneb, which won’t officially set for those Interlochen northward. Low in the south is the loneliest star Fomalhaut. In the northeast is the winter star Capella, which also doesn’t set for the IPR listener area, but spends summer nights hiding behind hills and trees in the north. Low in the east is the last of our bright stars, Aldebaran in Taurus the bull, which will be playing hide and seek with the Moon next week.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The bright first magnitude stars of autumn shown for 8 p.m. November 20, 2015. If you are closer to your time meridian, we’re 43 minutes behind ours, you will see two more bright stars in the east: Red Betelgeuse and blue-white Rigel. Created using Stellarium.
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
10/06/2015 – Ephemeris – Deneb our home-town star
Ephemeris for Tuesday, October 6th. The Sun will rise at 7:46. It’ll be up for 11 hours and 27 minutes, setting at 7:14. The Moon, 2 days past last quarter, will rise at 2:36 tomorrow morning.
We, here in Traverse City, Michigan have a pretty unique relation to the bright star Deneb, as is any location near 45 degrees north latitude. Tonight at 9:23 Deneb will be three-quarters of a degree due north of the zenith. Due north means that it’s on our meridian, a line you may remember from your school days. For astronomers it passes from the north point on the horizon, through the overhead point or zenith to the south point on the horizon. Also due to our latitude Deneb is circumpolar, meaning that it doesn’t quite set on a clean northern horizon. Deneb and 56 other stars are used for celestial navigation, which is still taught in case the GPS system goes down due to solar or enemy action.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Deneb nearly at the zenith from Traverse City. Created using Cartes du Ciel.
Deneb is close to the horizon due north. Created using Cartes du Ciel.
10/05/2015 – Ephemeris – The loneliest star
Ephemeris for Monday, October 5th. The Sun will rise at 7:45. It’ll be up for 11 hours and 31 minutes, setting at 7:16. The Moon, 1 day past last quarter, will rise at 1:38 tomorrow morning.
There’s a bright and lonely star that appears low in the south for only seven and a half hours a night on autumn evenings. It’s appearance is a sign as sure as the falling leaves that autumn is here At 10 p.m. tonight it’s low in the south-southeast. The star’s name is Fomalhaut, which means fish’s mouth. This is appropriate because it’s in the constellation of Piscis Austrinus, the southern fish. At our latitude it’s the fish that got away, because Fomalhaut appears to be quite alone. The dimness of the constellation’s other stars and location close to the horizon make the fainter stars hard to spot. The earth’s thick atmosphere near the horizon reduces the stars brightness by a factor of two or more, so Fomalhaut appears to keep a lonely vigil in the south.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Fomalhaut appears quite alone in the south-southeast at about 10 p.m. Created using Stellarium.
Actually Fomalhaut isn’t all that alone, It apparently has a companion planet.
Fomalhaut b and it’s path around its star. Credit: NASA, ESA, and P. Kalas (University of California, Berkeley and SETI Institute)
07/27/2015 – Ephemeris – Deneb, the dimmest of the Summer Triangle stars. But is it really?
Ephemeris for Monday, July 27th. The Sun rises at 6:23. It’ll be up for 14 hours and 51 minutes, setting at 9:14. The Moon, 3 days past first quarter, will set at 3:36 tomorrow morning.
This evening when it gets dark the bright star Deneb in Cygnus the swan will be high in the east northeast. Deneb is the dimmest star of the summer triangle. Of the other stars of the triangle, Vega is very high in the east, while Altair is lower in the southeast. While Deneb’s apparent magnitude, or brightness as seen from earth, makes it the dimmest of the three bright stars, Deneb’s vast distance of possibly 2,600 light years makes it over 100 times the distance of Vega. If brought as close as Vega, Deneb would be almost as bright as the full moon. It is as bright as two hundred thousand suns. It apparently has run out of hydrogen in its core. Once a blue super giant star, it’s currently evolving through the white supergiant stage.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Summer Triangle. Created using Stellarium and The Gimp.
One of my old photographs of Deneb and the North American Nebula digitized from a slide.
The Hertzsprung-Russell diagram of star luminosity vs. surface temperature. Note that Deneb is at the top center, while the Sun is lower on the main sequence. Credit: European Southern Observatory (ESO).
07/23/2015 – Ephemeris – Altair, the nearest star of the Summer Triangle
Thursday, July 23rd. Today the Sun will be up for 14 hours and 59 minutes, setting at 9:18. The Moon, 1 day before first quarter, will set at 12:57 tomorrow morning. Tomorrow the Sun will rise at 6:20.
The southernmost star of the Summer Triangle is Altair, high in the south. The other two stars of the triangle are Vega nearly overhead, and Deneb high in the east. Altair is the closest of the three at a distance of 16.7 light years away. One light year is nearly 6 trillion miles. Altair is 10 times the brightness of the sun. If seen at Altair’s distance, the sun would only be as bright as one of the two stars that flank it. What is rather different about Altair is its rapid rotation. While it’s almost twice the sun’s diameter, it rotates once in only 8.9 hours, The CHARA Interferometer at Mt. Wilson has actually imaged its squashed disk in the infrared. Our sun’s a slow poke, taking nearly a month to rotate once.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Summer Triangle. Created using Stellarium and The Gimp.
Aquila the Eagle in the southeastern sky. Created using Stellarium.
Credit: Zina Deretsky, National Science Foundation
07/21/2015 – Ephemeris – Vega, the brightest star of the Summer Triangle
Ephemeris for Tuesday, July 21st. Today the Sun will be up for 15 hours and 3 minutes, setting at 9:20. The Moon, 3 days before first quarter, will set at 12:01 tomorrow morning. Tomorrow the Sun will rise at 6:17.
The bright star high in the east is Vega, one of the stars of the Summer Triangle an informal constellation called an asterism. Vega belongs to the official constellation Lyra the harp, which includes a narrow parallelogram of stars to its south. Vega was regarded by astronomers as a standard calibration star. Though a first magnitude star, its actual magnitude is 0.03 and slightly variable. It is a type A0 (A-zero) pure white star, and is 25 light years away. Astronomers however got a shock in 1983 when calibrating the Infrared Astronomy Satellite (IRAS) on it: Vega showed an excess of Infrared radiation that means the star is orbited by a disk of dust, perhaps the beginnings of a planetary system. Due to the slow wobble of the earth’s axis Vega will be our pole star in 14 thousand years.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Summer Triangle. Created using Stellarium and The Gimp.
Magnified view of Lyra. Created using Stellarium.
Vega in the mid-infrared from the Spitzer Infrared Satellite. Credit: NASA/JPL-Caltech/University of Arizona
07/09/2015 – Ephemeris – The first stars to appear at night
Ephemeris for Thursday, July 9th. Today the Sun will be up for 15 hours and 23 minutes, setting at 9:29. The Moon, 1 day past last quarter, will rise at 2:05 tomorrow morning, and tomorrow the Sun will rise at 6:07.
Let’s check out all the bright stars in the evening sky, as it gets dark tonight. Low in the west are the planets Venus and Jupiter. High in the west is the bright yellow-orange star Arcturus. In the northwest is the Big Dipper, whose curved handle points to Arcturus. Straightening that curve to a spike will point to Spica a blue-white star low in the southwest. The planet Saturn is located in the south. Below and left of it is the red star Antares which usually twinkles merrily. High in the east is the bright white star Vega. To its lower right is Altair, and to its lower left the star Deneb. Vega, Altair and Deneb make the Summer Triangle, whose rising in the east signals the coming of summer.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
I talked about seeing the first stars a month ago. It seems that in holding star parties this time of year we spend a lot of time watching the first stars appear. I wanted to discuss the Summer Triangle, but it wandered off to what you see above. I’ll get there next week, I promise.
The first stars and planets to appear. See if you can located them from the text. Created using Stellarium for about 10 p.m., July 9, 2015.
Bob Moler's Ephemeris Blog 