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04/23/2018 – Ephemeris – The Ursa Major Association

April 23, 2018 Comments off

Ephemeris for Monday, April 23rd. The Sun rises at 6:45. It’ll be up for 13 hours and 52 minutes, setting at 8:37. The Moon, 1 day past first quarter, will set at 4:15 tomorrow morning.

The usual impression is to think that the stars of a constellation are actually located close together. This is usually not true. The stars of a constellation can be at vastly different distances. The Big Dipper is different. The five stars, excepting the two end stars of the dipper and 12 other dimmer stars in the general area are of similar distance and have the same motion through space. The group is called the Ursa Major Moving Cluster or Ursa Major Association, and is moving about 9 miles per second relative to the solar system to the east and south. An association is a rather loose, sparse star cluster. This association lies about 75 light years away. If it were five times farther away, it would be the same distance as the Pleiades.

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

Addendum

The Big Dipper

Craig Brown’s drawing of where the stars of the Big Dipper are and are heading. Click on the image to go to Craig’s WordPress post.

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03/26/2018 – Ephemeris – The Moon will slide below the Beehive star cluster tonight

March 26, 2018 Comments off

Ephemeris for Monday, March 26th. The Sun will rise at 7:34. It’ll be up for 12 hours and 28 minutes, setting at 8:02. The Moon, 2 days past first quarter, will set at 5:34 tomorrow morning.

Tonight the gibbous Moon will be seen among the stars of Cancer the crab. It will just about completely drown Cancer’s dim stars out. That is no exception to one of the famous group of stars in Cancer, the Beehive star cluster. It is going to take binoculars or a small telescope to spot them. The star cluster will be at the 11 o’clock position from the Moon. When looking for the cluster try to keep the Moon out of your field of view. The cluster is about 4 moon-widths away, so aim high and slowly aim those binoculars down. There will be other times in the next few months to catch the Moon near the Beehive, when the Moon will be a not so overwhelming crescent as the cluster moves westward in the evening sky with the rest of the stars.

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

Addendum

The Moon and the Beehive Star Cluster

The Moon and the Beehive Star Cluster tonight at 9 p.m. March 26, 2018. The star cluster will be very difficult to spot. Created using Stellarium, however I had to boost the brightness of the stars and eliminate the atmosphere control to darken the sky enough to see the cluster. Good luck!

Cancer the Crab

Cancer the crab finder chart for a dark night. Note the beehive cluster, also known to amateur astronomers as M44, along with other catalog names. Prior to the invention of the telescope this cluster was known as Praesepe which means “Manger”. Created using Stellarium and GIMP.

01/08/2018 – Ephemeris – The Pleiades in Greek myth

January 8, 2018 Comments off

Ephemeris for Monday, January 8th. The Sun will rise at 8:19. It’ll be up for 9 hours and 1 minute, setting at 5:20. The Moon, at last quarter today, will rise at 1:17 tomorrow morning.

The large and bright constellation of Orion is now in the southeast at 9 p.m. It is seen as an upright rectangle of bright stars, with a belt of three stars in the center. Orion is a minor character in Greek mythology. Orion was the son of Neptune, and was a hunter. He had an ill-fated romance with Merope, whose father King Oenopion, had him blinded. After having his sight restored, Orion became a companion of Diana goddess of the hunt and they wanted to marry. Apollo, Diana’s brother disapproved of Orion also and was able to trick Diana into accidentally killing Orion with an arrow. The heart-broken Diana then placed Orion in the sky with his hunting dogs, were we see him to this day.

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

Addendum

Hyades and Pleiades

The Pleiades (right) and the Hyades (left) in this photograph I took January 4, 2016.

Named Pleiads

The named stars of the Pleiades. This is also showing more stars than can be seen with the naked eye. This is the number of stars that can be seen in binoculars, which is the best way to observe them. Most telescopes are offer too much magnification to fit all the stars in. A thirty power wide-angle eyepiece can just fit all the stars in. Created using Stellarium.

11/06/2017 – Ephemeris – Taurus’ angry red eye, Aldebaran

November 6, 2017 1 comment

Ephemeris for Monday, November 6th. The Sun will rise at 7:27. It’ll be up for 9 hours and 57 minutes, setting at 5:24. The Moon, 3 days past full, will rise at 7:52 this evening.

Last night the Moon passed in front of or occulted the bright star Aldebaran. Above right of Moon tonight is Aldebaran the bright orange star with a V shape of other stars in the face of Taurus the bull. Aldebaran appears at the lower left tip of that letter V laying on it’s side. With the bright Moon, it might take binoculars to pull out the faint stars of the V. Aldebaran isn’t actually part of the group, called the Hyades star cluster. The cluster is about 153 light years away, while Aldebaran is 65 light years away. 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. The name Aldebaran means “Follower” because it follows the Pleiades star cluster above it.

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

Addendum

Aldebaran

Aldebaran in the Hyades (unlabeled), with also the Pleiades, unlabeled, at the top and the Moon. at 9 p.m., November 6, 2017. Created using Stellarium.

Ephemeris Extra – Some easy summertime deep sky objects

July 8, 2017 1 comment

The finder charts were created using Cartes du Ciel (Sky Charts).  This post is based on my article in the July 2017 Stellar Sentinel, the newsletter of the Grand Traverse Astronomical Society.  It’s part of the Extras section for those receiving the emailed version.

What are Deep Sky Objects?  These are objects, other than individual stars, beyond the solar system generally visible in binoculars or telescopes rather than the naked eye such as galaxies, nebulae and star clusters.

HerculesThe Great Hercules Globular Star Cluster, M13 is the finest globular star cluster in the northern hemisphere of the sky. It is visible from late spring to early autumn. Globular star clusters have populations of hundreds of thousands of stars. They date back to the origin of the Milky Way of ten or a bit more billion of years old. There are only about 150 of these that belong to the Milky Way Galaxy. M13 is visible in binoculars on the western side of the Keystone pattern of stars, about one-third the distance from the north star on that side to the south side. It takes a much larger telescope to see individual stars. The star cluster will be a large circular glow. M92 is another star cluster which is dimmer and will be quite a challenge to find.

The Ring Nebula, M57 is small and cannot be seen with the naked eye or with binoculars, but it is still reasonably easy to find. A nebula is a cloud of gas and/or dust. M57 is in the constellation of Lyra the harp, a constellation visible in summer and early autumn. Point the telescope’s finder about half way between the two southern stars of the parallelogram of stars that’s the harp’s body, Sulafat and Sheliak. Move the telescope in a small spiral enlarging the search pattern by half the field of view at a time. The Ring Nebula will appear a ghostly small circular glow. Once centered, more magnification may be used. The center will be darker than the edge. Inside is a very faint invisible star that blew out its outer layers of gas into a smoke ring near the end of its life.

The Southern Milky Way contains lots of star clusters and nebulae. The chart below can be used to find the many Messier objects. Or just sweep through this gold mine of objects with binoculars or a low power telescope, most of which are in the next spiral arm in toward the center of the Milky Way. As far as the symbols go, open dotted circles are open or galactic star clusters. Crossed circles are globular star clusters. Squares are nebulae. M8, the Lagoon nebula, and M16 the Eagle nebula also contain star clusters. M8 and its associated star cluster appear as a horizontal spash of light in binoculars. As far as popular names go: M11 is the Wild Duck Cluster, M17 is the Omega or Swan Nebula, and M20 is the Trifid Nebula.  An easy binocular star cluster is M7.Southern summer Milky Way DSOs

The Milky Way Overhead contains some notable deep sky objects. Note that the Milky Band splits here, though closer to the star Sadr in Cygnus than it shows here. The Dark expanse that runs through Aquila is called the Great Rift, and is caused by a cloud of dust and gas. Its edges can be probed with binoculars, especially in Aquila by watching star density drop off as one pans through the area. Don’t forget the blue and gold binary star Alberio. There’s another fainter blue and gold binary about a degree directly north of the Ring Nebula, M57. It’s 8th magnitude. The unmarked planetary nebula just above the second ‘l’ in Vulpecula is M27, the Dumbbell nebula. The other Messier (M) numbers are relatively easy to find. The large nebula below Deneb is the North American Nebula which can actually be seen with the naked eye or with binoculars on a moonless night away from city lights. The three-part nebula below Cygni is the Veil Nebula, a supernova remnant and very hard to spot but doable. The cluster Cr 399 (Collinder 399 or Brocchi’s Cluster) is better known as the Coathanger and is best seen in binoculars or a telescope finder, which inverts it, making it a properly oriented hanger.

 

 

05/12/2017 – Ephemeris – There will be a star party at the Sleeping Bear Dunes National Lakeshore Saturday night the 13th

May 12, 2017 Comments off

Ephemeris for Friday, May 12th.  Today the Sun will be up for 14 hours and 42 minutes, setting at 9:00, and it will rise tomorrow at 6:16.  The Moon, 2 days past full, will rise at 10:37 this evening.

Tomorrow night May 13th there will be, weather permitting a star party at  Sleeping Bear Dunes National Lakeshore, this time the venue is Pierce Stocking Scenic Drive at Stop number 3, the Dunes Overlook.  The event starts at 9 p.m., while it’s still light out and the location can be found.  Park at Picnic Mountain, which is after Stop 2, and right before stop 3, and walk over.  The planet Jupiter and all four of its bright moons and cloud bands will be featured.  Sharp eyed observers will also be able to see the Great Red Spot.  As the sky darkens there will be a twilight talk about the wonders of the spring sky.  Near the last half hour it will be dark enough to spot some of the galaxies and globular star clusters of spring.  The star party is made possible by the rangers of the park and the Grand Traverse Astronomical Society.

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

Addendum

Telescopic Jupiter

Jupiter, its cloud bands, Great Red Spot and moons as it might be seen around 10 p.m. at the star party. The actual orientation will depend on the telescope used to view them. Created using Cartes du Ciel (Sky Charts).

 

04/18/2017 – Ephemeris – How Queen Berenice lost her hair

April 18, 2017 Comments off

Ephemeris for Tuesday, April 18th.  The Sun rises at 6:52.  It’ll be up for 13 hours and 38 minutes, setting at 8:31.  The Moon, 1 day before last quarter, will rise at 3:04 tomorrow morning.

High in the east-southeast at 10 p.m. is the tiny and faint constellation of Coma Berenices, or Berenice’s Hair.  In it are lots of faint stars that 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 star cluster is 280 light years away, nearly twice as far as the Hyades, the face of Taurus the Bull setting in the west.  The story behind it was that Berenice was the Queen of Egypt, whose husband was away at war.  She offered her golden tresses to the gods for the king’s safe return.  The hair, was placed in a temple.  However the offering disappeared when the king returned.  Ever since the constellation of Coma Berenices has been seen to commemorate the queen’s sacrifice.

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

Coma Berenices finder chart

Coma Berenices finder chart for 10 p.m. April 18, 2017. Created using Stellarium.

Coma Berenices

Approximate 7 power binocular field of view of the Coma Berenices Cluster. Created using Carted du Ciel (Sky Charts).

Addendum