Archive
07/29/2016 – Ephemeris – Aquila the Eagle, third constellation of the Summer Triangle
Ephemeris for Friday, July 29th. The Sun rises at 6:26. It’ll be up for 14 hours and 45 minutes, setting at 9:11. The Moon, 3 days past last quarter, will rise at 3:20 tomorrow morning.
Aquila the eagle is a constellation that lies in the Milky Way. It’s in the southeastern sky as it gets dark. Its brightest star, Altair is one of the stars of the Summer Triangle, a group of three bright stars seen now in the eastern sky in the evening. Altair, in the head of the eagle, is flanked by two slightly dimmer stars, the shoulders of the eagle. The eagle is flying northeastward through the Milky Way. Its wings are seen in the wing tip stars. A curved group of stars to the lower right of Altair is its tail. Within Aquila the Milky Way shows many dark clouds as part of the Great Rift that splits it here. The other summer bird is Cygnus the swan, which I talked about Tuesday, above and left of Aquila, flying in the opposite direction.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Aquila the Eagle in the southeastern sky. Created using Stellarium.
08/13/2015 – Ephemeris – The constellation Sagittarius, toward the heart of the Milky Way
Thursday, August 13th. The Sun rises at 6:42. It’ll be up for 14 hours and 9 minutes, setting at 8:52. The Moon, 1 day before new, will rise at 6:48 tomorrow morning.
The Milky Way runs from north to south through the heavens at 11 p.m. You’ll notice that the Milky Way is brighter and broader just above the horizon in the south. In that glow in the south is a star pattern that looks like the stout little teapot of the children’s song, with a the Milky way like steam rising from the spout, which faces the west. This pattern of stars is the major part of the constellation called Sagittarius. According to Greek mythology Sagittarius is a centaur with a bow and arrow poised to shoot Scorpius the scorpion to the right. This centaur is called Chiron, the most learned of the breed, centaurs usually being a rowdy bunch. The center of the pin wheel of our galaxy lies hidden beyond the stars above the spout of the teapot.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Sagittarius and Scorpius mythological view 10 p.m. August 13, 2015. Created using Stellarium.
Location of the center of the Milky Way and the Teapot of Sagittarius.
05/08/2015 – Ephemeris – May’s missing Milky Way
Ephemeris for Friday, May 8th. Today the Sun will be up for 14 hours and 32 minutes, setting at 8:55. The Moon, 3 days before last quarter, will rise at 1:08 tomorrow morning. Tomorrow the Sun will rise at 6:22.
In May we look up to the sky and notice that the Milky Way is missing. Will not really it’s as if the sky has pattern baldness with the Milky Way as a fringe on the horizon around the north half of the sky. Overhead, where none should be is a galactic star cluster, a star cluster that should normally be in the Milky band. That cluster is the constellation of Coma Berenices. Its is a sparse star cluster of about 50 stars only 288 light years away. If we were a thousand light years from it, it would appear in the Milky band. One notes too that the stars of spring are also fewer, not the riot of stars we see in the winter or late summer. The Milky Way galaxy is a thin disk, and in spring we are looking out the thin side.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Star Chart for May 2015. Note the Milky way in the north. The Coma Berenices cluster is located between the labels CnV and Com. Created using my LookingUp program.
Messier objects, mostly galaxies (ovals) in the spring sky. Created using my LookingUp program.
Most of the galaxies in the above chart belong to the Virgo Cluster a cluster of several thousand galaxies about 53 million light years away. Charles Messier was a comet hunter active in the period around the time of the American Revolution at the Paris Observatory. He made a catalog of fuzzy objects he ran into that didn’t move and thus were not comets. The Messier catalog, which ran to 110 galaxies, star clusters and nebulae, some added posthumously, became a must-see list of some of the best sights for the telescope.
11/14/2014 – Ephemeris – When Galaxies collide… With ours (Gulp)
Ephemeris for Friday, November 14th. The sun will rise at 7:37. It’ll be up for 9 hours and 37 minutes, setting at 5:15. The moon, at last quarter today, will rise at 12:33 tomorrow morning.
Yesterday we looked at the closest spiral galaxy to our own Milky Way, the Great Andromeda Galaxy. I said that it would collide with the Milky Way in about 4 billion years. Usually no stars are harmed by such a collision. What does collide are the dust and gasses in each galaxy, that will trigger a burst of star formation. Over the next several billion years the two galaxies will probably merge into one giant elliptical galaxy. The sun at that time will see some changes of life the too. The Earth would by then be uninhabitable because the sun would be too hot, and by then would begin to bloat out into a red giant star. It would be a great spectacle, but no one would be around to watch it. However there are many distant colliding galaxies to watch.
Closer to home, Saturday night there will be a star party at NMC’s Rogers Observatory starting at 9 p.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Great Andromeda Galaxy (M31). Image taken by Scott Anttila.
Here’s a link to a YouTube video of a computer simulation of the collision of the Andromeda galaxy with our Milky Way galaxy.
08/26/2014 – Ephemeris – The Great Rift
Ephemeris for Tuesday, August 26th. The sun rises at 6:57. It’ll be up for 13 hours and 31 minutes, setting at 8:29. The moon, 1 day past new, will set at 8:45 this evening.
High overhead the Milky Way is seen passing through the Summer Triangle of three bright stars. Here we find the Milky Way split into two sections. The split starts in the constellation of Cygnus the Swan or Northern Cross very high in the east. The western part of the Milky Way ends southwest of the Aquila the eagle. This dark dividing feature is called the Great Rift. Despite the lack of stars seen there, it doesn’t mean that there are fewer stars there than in the brighter patches of the Milky Way. The rift is a great dark cloud that obscures the light of the stars behind it. Sometimes binoculars can be used to find the edges of the clouds of the rift, as stars numbers drop off suddenly. This is especially easy to see in Aquila.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Great Rift in the Milky Way. Created using Stellarium.
08/14/2014 – Ephemeris – The Milky Way now spans the sky in the evening
Ephemeris for Thursday, August 14th. The sun rises at 6:43. It’ll be up for 14 hours and 5 minutes, setting at 8:49. The moon, 3 days before last quarter, will rise at 10:58 this evening.
We’ll get a bit of darkness tonight, but it will be the start of about two weeks of the best sky viewing of the year. Now is the time the summer Milky Way is displayed to its fullest to the southern horizon. City folk come to our area and are sometimes fooled by the brightness and expanse of the Milky Way and think it’s clouding up. Yes those are clouds indeed, but they are star clouds. Binoculars will begin to show them to be millions of stars, each too faint to be seen by themselves to the unaided eye, but whose combined glow give the impression of a luminous cloud. Binoculars are the ideal tool to begin to explore the Milky Way. Objects still too fuzzy can be checked out with a telescope to reveal their true nature.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Milky Way at 10 p.m. on August 14, 2014. Residual glow in the west is from the Sun, to the east is for the Soon to rise Moon. There is also an odd artifact connected to the solar glow. Created using Stellarium.
04/18/2014 – Ephemeris – The constellation Coma Berenices
Ephemeris for Good Friday, Friday, April 18th. The sun rises at 6:53. It’ll be up for 13 hours and 37 minutes, setting at 8:31. The moon, 3 days past full, will rise at 12:21 tomorrow morning.
High in the southeast at 10 p.m. is a tiny and faint constellation of Coma Berenices, or Berenice’s hair. In it are lots of faint stars arrayed to look like several strands of hair. The whole group will fit in the field of a pair of binoculars, which will also show many more stars. The hank of hair was supposed to belong to Berenice, Queen of Egypt, of the 3rd century BCE. Coma Berenices is the second closest star cluster to us at only 250 light years away, after the Hyades, the face of Taurus the bull now setting in the west. It’s in an odd spot for a galactic star cluster, that’s supposed to lie in the plane of the Milky Way. It actually lies at the galactic pole. That’s an illusion because it’s so close to us. It’s still really in the plane of the Milky Way.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Coma Berenices finder chart for 10 p.m. April 18, 2014. Created using Stellarium.
Coma Berenices and galactic coordinates showing how close to the galactic pole it is. Created using Cartes du Ciel
Mercator projection of the Milky Way and some bright open or galactic clusters (brown disks). See how the distribution hugs the milky band. Clusters farther away are either close to us or very old for open clusters. Created using Cartes du Ciel.
09/26/2013 – Ephemeris – The Milky Way is crossing overhead
Ephemeris for Thursday, September 26th. The sun will rise at 7:34. It’ll be up for 11 hours and 57 minutes, setting at 7:31. The moon, at last quarter today, will rise at 12:17 tomorrow morning. | At 10 this evening the Milky Way will pass directly overhead. The bright star Deneb of the Summer Triangle and at the head of the Northern Cross is directly overhead at that time. Deneb is incidentally the tail of Cygnus the swan. The Milky Way stretches from the northeast to the southwest where the Teapot of Sagittarius is tipping, pouring out its tea on the horizon. The Milky Way can be enjoyed with the naked eye, binoculars or telescope. With the naked eye, we see it as the pre-scientific cultures did. The Milky way was a pathway of milk, the path that the American Indian warriors journeyed to the hereafter, the stars their camp fires shining in the night. In reality it is what we can see of our galaxy.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Milky Way crosses the sky overhead at 10 p.m., September 26, 2013. Horizon to horizon view. Created using Stellarium.
07/29/2013 – Ephemeris – The constellation Aquila the eagle
Ephemeris for Monday, July 29th. The sun rises at 6:25. It’ll be up for 14 hours and 45 minutes, setting at 9:11. The moon, at last quarter today, will rise at 12:46 tomorrow morning.
Aquila the eagle is a constellation that lies in the Milky Way. It’s in the southeastern sky as it gets dark. Its brightest star, Altair is one of the stars of the Summer Triangle, a group of three bright stars seen now in the eastern sky in the evening. Altair, in the head of the eagle, is flanked by two slightly dimmer stars, the shoulders of the eagle. The eagle is flying northeastward through the Milky Way. Its wings are seen in the wing tip stars. A curved group of stars to the lower right of Altair is its tail. Within Aquila the Milky Way shows many dark clouds as part of the Great Rift that splits it here. The other summer bird is Cygnus the swan, above and left of Aquila, flying in the opposite direction, southward.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Aquila with the other constellations in the Summer Triangle. Created using Stellarium.
06/11/2013 – Ephemeris – The Milky Way rising
Ephemeris for Tuesday, June 11th. Today the sun will be up for 15 hours and 30 minutes, setting at 9:27. The moon, 3 days past new, will set at 11:24 this evening. Tomorrow the sun will rise at 5:56.
Last Saturday night at the Sleeping Bear Dunes star party, at the end of the official star party after 11 we were looking to the east. The only blemish to the dark skies was the light pollution dome of Traverse City to the east. Rising out of that yellowish haze and barely visible was the Milky Way. In the spring skies the Milky way almost rings the horizon. The only portion visible is low in the north, too close to the horizon to be really visible. Now that spring is almost over , we are transitioning at the end of twilight to the summer stars and the brilliant Milky Way of summer is rising in the east. By August it will run across the sky from northeast to the south, revealing in the south the bulge of the galactic center.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Milky Way Rising at 11:15 p.m. on June 11, 2013. Created using Stellarium.
The three named stars are those of the Summer Triangle.
Bob Moler's Ephemeris Blog 