Archive

Archive for the ‘Star Clusters’ Category

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.

 

 

Advertisements

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

12/15/2015 – Ephemeris – The Seven Sisters of the Pleiades

December 14, 2016 Comments off

Ephemeris for Thursday, December 15th.  The Sun will rise at 8:13.  It’ll be up for 8 hours and 49 minutes, setting at 5:02.  The Moon, 2 days past full, will rise at 7:21 this evening.

While I’ve mentioned the Pleiades with regard to its neighboring stars and constellations several times this autumn I haven’t looked at this beautiful star cluster itself.  The Pleiades appears as a  group of six or seven stars visible to the naked eye, of over a hundred stars, and is also known as the Seven Sisters.  Some also mistake it for the Little Dipper, due to the little bowl shape in the center of the cluster.  I call it the “tiny dipper”.  The real Little Dipper is now hanging off Polaris in the north.  There are a lot of stories about the Pleiades from many different cultures.  From the Greek and Roman cultures we get our best known stories of them, that the seven sisters were the daughters of the god Atlas and Pleione.  The 9 brightest stars bear the names of the sisters and their parents.

Times 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, the face of Taurus the bull (left) in this photograph I took 11:23 p.m. 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 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.  Note that this view is the orientation of the cluster at 8p.m. tonight.

 

11/28/2016 – Ephemeris – The Hyades the star cluster in the face of Taurus the bull

November 28, 2016 Comments off

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

the Hyades, Taurus, Orion and the Pleiades

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

Closeup of the Hyades and the Pleiades. Created using Stellarium.

04/05/2016 – Ephemeris – Coma Berenices, the second closest star cluster

April 5, 2016 Comments off

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

Coma Berenices finder chart 10 p.m., April 5, 2016. Created using Stellarium.

Coma Berenices binocular view

Coma Berenices as it might look in a pair of binoculars. Telescopes are too powerful. Created using Stellarium.

11/09/2015 – Ephemeris – The celestial sisters

November 9, 2015 Comments off

Ephemeris for Monday, November 9th.  The Sun will rise at 7:31.  It’ll be up for 9 hours and 50 minutes, setting at 5:21.   The Moon, 2 days before new, will rise at 6:15 tomorrow morning.

A marvelous member of the autumn skies can be found rising in the east at 8 in the evening.  It is the famous star cluster called the Pleiades or the Seven Sisters.  I might also add the ‘Tiny Dipper’.  Many people can spot a tiny dipper shape in its six or seven stars, and mistake it for the Little Dipper.  As nearsighted as I am, though corrected, I’ve never been able to see more than a few stars and a bit of fuzz.  However with binoculars, over a hundred stars appear along with the dipper shape of the brightest.  The fuzz I saw was unresolved stars, but in photographs the Pleiades actually contains wisps of dust that reflect the star’s blue light which the cluster is passing through.  In Greek and Plains Indian mythology the sisters were young maidens.

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

Addenda

Pleiades Rising

The Pleiades rising at 8 p.m. November 9th. Created using Stellarium.

The Pleiades, about what you'd see in binoculars.

The Pleiades, about what you’d see in binoculars.

I’ll be in Cadillac tonight

I’ll be giving an illustrated talk tonight to the Cadillac Garden Club at St. Ann’s Parish in Cadillac at 7 p.m. I’ll be talking about all the ways the Sun affects the Earth.  At 8 p.m., if it’s clear,  I and other members of the Grand Traverse Astronomical Society will have some telescopes set up in the parking lot to view the wonders of the heavens.  The meeting appears to be open to the public and the viewing after definitely is.