Archive
04/21/2017 – Ephemeris – Mars is passing south of the Pleiades today
Ephemeris for Friday, April 21st. The Sun rises at 6:47. It’ll be up for 13 hours and 47 minutes, setting at 8:35. The Moon, 2 days past last quarter, will rise at 4:54 tomorrow morning.
Mars in its ever eastward trek through the constellations of the Zodiac is now just south of the Pleiades or Seven Sisters star cluster in the western evening twilight. By 10 p.m. Mars will be 10 degrees above the western horizon. That’s the width of a fist held at arm’s length. Because of our location on the Earth, the setting sky is tilted, so Mars being south of the Pleiades is to the lower left of it. The bright star Aldebaran, now brighter than Mars is to the left of it with the V-shaped star cluster called the Hyades, in mythology, half sisters of the Pleiades, filling out the face of Taurus the bull. Mars will finally be overtaken by the Sun on July 26th. After that it will spend more than a year to come closer to us than at any time since August 2003.
First star party of the year at the Sleeping Bear Dunes National Lakeshore
Tomorrow night the Rangers of the Sleeping Bear Dunes National Lakeshore and the Grand Traverse Astronomical Society will host a Star Party at the Dune Climb featuring the planet Jupiter, and the stars of spring. It starts at 9 p.m.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Mars and the Pleiades at 10 p.m. April 21, 2017. Aldebaran and the Hyades which is the face of Taurus the bull is to the left of them. Created using Stellarium.
Note that the nebulosity in the Pleiades exists, but is not visible to the naked eye.
12/12/2016 – Ephemeris – The Moon will cover the eye of the bull tonight
Ephemeris for Monday, December 12th. The Sun will rise at 8:11. It’ll be up for 8 hours and 51 minutes, setting at 5:02. The Moon, 1 day before full, will set at 7:21 tomorrow morning.
Late tonight the nearly full moon will pass in front of the bright star Aldebaran. This will be a difficult event to spot due to the brightness of the Moon. It will take a telescope at least to spot Aldebaran, the bright star the is the bloodshot eye in the face of Taurus the bull. It might help to spot Aldebaran an hour or two early, while it’s some distance left of the Moon. Aldebaran will disappear at the Moon’s left edge, while its a tiny distance from the bright edge of the Moon at around 10:54 p.m. Aldebaran will reappear at about 12:09 a.m. Make sure to start observing several minutes early since these are low precision times, plus your location affects the times. These times are most accurate in the Western Lower Peninsula of Michigan.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon moves from west to east, so the occultation events will happen earlier to the west and later to the east. Planetarium programs can be used to simulate the position of the Moon and stars and can be used to estimate the occultation start and end times. To be accurate your location longitude and latitude must be entered in the program.
The times I developed are from the free program Cartes du Ciel and are within a minute of that provided by the more accurate program Occult4, which can be downloaded for free at the site below. Planetarium programs are close enough, however. Occult4 is somewhat difficult to use.
If you’re out keep a look out for some bright Geminid Meteors. Their shower will reach its peak tomorrow night.
Start of the occultation at 11:54 p.m EST December 12, 2016. The grid is altitude and azimuth. Created using Cartes du Ciel.
End of the occultation at 12:09 a.m EST December 13, 2016. The grid is altitude and azimuth. Created using Cartes du Ciel.
Path of the occultation. Locations between the bright boundaries would see the occultation at night. Created by the software program Occult4 by the International Occultation Timing Association.
An animation created by Occult4 of the occultation of Aldebaran and some of the dimmer stars of the Hyades.
Eclipse and occultation information and software can be accessed at http://occultations.org/ the website of IOTA, the International Occultation Timing association.
12/08/2016 – Ephemeris – Aldebaran, the follower
Ephemeris for Thursday, December 8th. The Sun will rise at 8:07. It’ll be up for 8 hours and 54 minutes, setting at 5:02. The Moon, 1 day past first quarter, will set at 2:26 tomorrow morning.
The central constellation of winter, Orion, is low in the east-southeast at 9 p.m. Above it is Taurus the bull. The bright orange star in Taurus is Aldebaran. Aldebaran appears at the bottom left tip of a letter V group of stars lying on its side that is the face of the bull. Aldebaran isn’t actually part of the group, called the Hyades star cluster. The cluster is about 151 light years away, while Aldebaran is a bit less than half that. The star has an orange hue because its surface is cooler than the Sun’s. However Aldebaran is 44 times larger in diameter, and shines 350 times brighter than the Sun. Next Monday night the 12th, the Moon will pass in front of Aldebaran in an event called an occultation I’ll have more information on it then. The name Aldebaran means The Follower, since it follows the Pleiades across the sky as the Earth rotates.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Aldebaran in the ‘V’ shape of the Hyades (The face of Taurus the bull) with the Pleiades above. Created using Stellarium.
11/28/2016 – Ephemeris – The Hyades the star cluster in the face of Taurus the bull
Ephemeris for Monday, November 28th. The Sun will rise at 7:57. It’ll be up for 9 hours and 7 minutes, setting at 5:04. The Moon, 1 day before new, will rise at 7:45 tomorrow morning.
Rising in the east now is the bright star Aldebaran an orange star that’s at one end of the sideways letter V of stars that is the head of Taurus the bull. Above it is the jewel-like Pleiades or Seven Sisters star cluster. There’s more to Taurus, like it’s freakishly long horns and front part of its body. But you can say you’ve seem Taurus, if you can spot his face. That V of stars is actually a star cluster called the Hyades, and in Greek Myth were the half-sisters of the Pleiades, also fathered by the god Atlas. Both the Hyades and Pleiades are being pursued by Orion, which as Robert Frost put it is throwing a leg over the eastern horizon at 8 to 9 pm. He isn’t the only one following the Pleiades, the name Aldebaran means “The Follower”.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
An animation showing the Hyades, Taurus, Orion and the Pleiades. Created using Stellarium and GIMP. Click on image to enlarge.
Closeup of the Hyades and the Pleiades. Created using Stellarium.
04/05/2016 – Ephemeris – Coma Berenices, the second closest star cluster
Ephemeris for Tuesday, April 5th. The Sun will rise at 7:15. It’ll be up for 13 hours and 1 minute, setting at 8:16. The Moon, 2 days before new, will rise at 6:53 tomorrow morning.
Midway up the sky in the east at 10 p.m. is a tiny sprinkle of faint stars arrayed to look like several strands of hair. It’s the constellation of Coma Berenices, or Berenice’s hair. The whole group will fit in the field of a pair of binoculars, which is the best way to see it, and will also show more stars. The cluster contains about 50 stars and lies at a distance of 280 light years from us, which makes it the second closest star cluster. The closest being the Hyades, that is the face of Taurus the bull now about to set in the west. The star cluster appears to be about 480 million years old. It is an open or galactic star cluster, born along the plane of the Milky Way. It appears away from the milky band due to its proximity to us.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Coma Berenices finder chart 10 p.m., April 5, 2016. Created using Stellarium.
Coma Berenices as it might look in a pair of binoculars. Telescopes are too powerful. Created using Stellarium.
12/17/2015 – Ephemeris – The bright star Aldebaran the “follower”
Ephemeris for Thursday, December 17th. The Sun will rise at 8:14. It’ll be up for 8 hours and 48 minutes, setting at 5:03. The Moon, 1 day before first quarter, will set at 12:07 tomorrow morning.
The central constellation of winter Orion, will be rising the east-southeast at 9 p.m. Above it is Taurus the bull. The bright orange star in Taurus is Aldebaran. Aldebaran appears at the lower left tip of a letter V group of stars that is the face of the bull. Aldebaran isn’t actually part of the group, called the Hyades star cluster. The cluster is about 151 light years away, while Aldebaran is 65. The star has an orange hue because its surface is cooler than the sun’s. However Aldebaran is 44 times larger in diameter, and shines 425 times brighter than the sun, if you include the infrared which our eyes can’t detect, or 150 times brighter in visible light. The name Aldebaran means “Follower” because it follows the Pleiades star cluster above through the night.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Aldebaran, the Hyades and Pleiades star clusters. Created using Stellarium.
Three views of Taurus the bull and Orion the hunter for 9 p.m. on December 8, 2015. Created using Stellarium and GIMP.
04/21/2015 – Ephemeris – The Moon will pass the Hyades star cluster today to pass near Venus tonight
Apr 21. This is Bob Moler with Ephemeris for Tuesday, April 21st. Today the Sun will be up for 13 hours and 46 minutes, setting at 8:35. The Moon, 3 days past new, will set at midnight. Tomorrow the Sun will rise at 6:47.
The moon, which was new last Saturday passed the face of the constellation Taurus the bull earlier today. The face of Taurus is a letter V shape of stars which is the star cluster called the Hyades. There’s a bright orange star that appears at the left tip of the V called Aldebaran, which actually doesn’t belong to the cluster. At 9:30 the crescent Moon will have also just passed the brilliant planet Venus. By then they will be nearly 8 degrees apart, which is a bit less than the width of a fist held at arm’s length. The Moon, Venus and all the planets move very close along the path of the Sun in the sky, called the ecliptic. Even so the Moon is now about 5 degrees south of the ecliptic and Venus about 2 degrees north of it.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon with Venus and the Hyades at 9:30 p.m. April 21, 2015. Note the Pleiades on the right. Created using Stellarium.
