There are two messier catalogue objects within Cassiopeia. The first of those, mentioned above, is M52, This is an open cluster of stars comprising about stars altogether. The brightest shines at magnitude 8 and the whole group is over 5, light years away. This is also an open cluster but not a particularly exciting one.
Also known as the Owl Cluster or ET cluster. NGC has a magnitude of 6. NGC is an elliptical galaxy which is part of our local group which includes the Milky Way and Andromeda and shines at magnitude 9. This is 2 million light years away. NGC is slightly dimmer elliptical galaxy shining at magnitude 9. Sky Safari. Stars to magnitude 5. Click for larger image. Courtesy, Sky Safari.
The five bright W stars of Cassiopeia, click for a larger version. Click for full size. It has an apparent magnitude of 5. The age of the cluster is estimated to be around 35 million years. It is 13 arcminutes 19 light years in diameter. The cluster was discovered by Charles Messier in The brightest stars in it are two yellow giants of magnitude 7. Messier is another open cluster in Cassiopeia. It lies approximately 10, light years from Earth and contains stars.
The age of the cluster is estimated to be about 25 million years. It was the last object Charles Messier entered into his catalogue. It appears in the same area of the sky as Messier 52 and lies at an estimated distance of 7, to 11, light years.
Also catalogued as Caldwell 11 and Sharpless , the nebula occupies an area of 15 by 8 arcminutes and has an apparent magnitude of It can be seen in 8- or inch telescopes, in which it appears as a large, very faint shell around the central star.
It is a hot, massive, blue O-type star with a surface temperature of about 37, K. The star is believed to be about 2 million years old. It produced the nebula with its stellar wind about 40, years ago. Cassiopeia A is a supernova remnant. It is notable for being the brightest astronomical radio source in the sky. It is the strongest radio source in the sky outside the solar system and was one of the first radio sources to be discovered, in It has a temperature of about 50 million degrees Fahrenheit.
The supernova occurred at an approximate distance of 11, years from Earth and the first light of the event is believed to have reached us about years ago. This stunning false-color picture shows off the many sides of the supernova remnant Cassiopeia A. Infrared data from the Spitzer Space Telescope are colored red; visible data from the Hubble Space Telescope are yellow; and X-ray data from the Chandra X-ray Observatory are green and blue.
It contains a large amount of ionised atomic hydrogen H II which is lit by the ultraviolet light of young, hot, blue stars. It was nicknamed the Pacman Nebula because of its resemblance to the character from the popular video game.
The nebula is 9, light years from Earth. It was discovered by American astronomer E. Barnard in NGC is an open star cluster, approximately 7, light years distant. It has an apparent magnitude of 6. It was discovered by the British astronomer Caroline Herschel in NGC is a dwarf spheroidal galaxy, approximately 2. The galaxy is classified as a type 2 Seyfert galaxy. It has an active galactic nucleus AGN. Atypical for a dwarf elliptical galaxy, NGC contains young clusters of stars and shows evidence of star formation that occurred in the cluster until recently.
NGC is another dwarf spheroidal galaxy in Cassiopeia, approximately 2. It was originally discovered by John Herschel in It has an apparent magnitude of Cassiopeia Constellation. October : visible in the north east sky at sunset 35 degrees above horizon. It will reach its peak at , and return to 30 degrees in the north west sky by sunrise. November : visible in the north east sky at sunset 45 degrees above horizon. It will reach its peak at , and return to 15 degrees in the north west sky by December : visible in the north east sky at sunset 60 degrees above horizon.
It will reach its peak at It will rotate towards the horizon, dropping too low in the north west sky to observe after Trajectory : The constellation is between degrees north, placing it around degrees from Polaris.
The constellation will rotate around the northern star maintaining its distance. As such viewers can expect it to follow an arch from the north east horizon arching across the north east sky until it reaches its peak high in the north sky, then following a parallel arch in the north west sky until it reaches near to the north west horizon. Those at very high northern hemisphere latitudes may also be able to view it cross low in the north sky to complete its rotation.
Its peak trajectory in Wadi Rum is 70 degrees above the northern horizon and is viewable in the evening from November to January. Not the right time for Ursa Major? Have a look what constellations you can see tonight. Cassiopeia is a collection of 5 bright stars near to each other in the north sky and is one of the easiest constellations to find without any aides. You will looking for 5 stars zigzagging in the north sky to form a W shape.
Depending on the position of this constellation the W could be facing any direction. However depending on you latitude it should always be around 30 degrees from the point directly north and above the horizon equal to your latitude. For viewers in Wadi Rum that is around 30 degrees.
That point is the north star and Cassiopeia constellation appears to be circling it. The top of the W will always be facing that point so when it is highest in the sky it will appear as an M, in the north east sky it will appear as a 3 and in the north west sky it will appear as an E. Step 1 : Make sure you are familiar with what time of night the constellation will be in the sky for the time of year you are looking.
Use the guide above to confirm the cycles and the appropriate area of the sky. Step 2 : The constellation will always be in the north sky so orient yourself with a clear view of the sky to the north. NOTE : All 5 stars in Cassiopeia are among the brightest visible from earth including those in the southern hemisphere that you never see and those that pass in the day so they are all very clear.
Step 3 : There will be very few groupings of bright stars within your view if you followed the previous steps and are looking at the right time and in the right direction. The only other candidate will be those of the Big Dipper in the Ursa Major constellation. The Big Dipper is 7 stars and does not appear as a W so you can now use that to guide you. Cassiopeia should be on the opposite side of the north star from Ursa Major. If you cross the point of the north star to a similar distance on the opposite side of the north star you should find Cassiopeia.
If Ursa Major is directly above the north star then you will need to look directly below it towards the northern horizon. If you are at a low latitude and have determined that it is below your point of visiblity you may need to come back later in the night.
The circumpolar constellations are rotating anticlockwise and move at around the same speed as the hour hands on a clock so you can determine the movement. Cassiopeia now known can be used to locate other constellations and determine the coordinal direction.
Until last century it was one of the primary guides for night time navigation in the northern hemisphere. As it is opposite the Big Dipper, one of these two bright star groupings is always visible in the northern hemisphere sky and can be used to locate the north star. Cassiopeia is one of the easiest stars to identify the shape of as all of its stars are bright. Rather than requiring the identification of a specific star and using this to find the shape, Cassiopeia is identifiable from its shape.
Although the form itself a basic W and difficult to visualise as the seated queen explained by Ptolemy it is a convenient grouping to locate and highly effective navigational tool in the northern hemisphere. Cassiopeia is the queen of Aethiopia, which was a historic region of the upper Nile and where modern day Ethiopia derives its name. She shared the throne with King Cepheus and now share neighbouring constellations in the night sky.
Cassiopeia is best is known from Greek mythology from the story of Perseus. Poseidon was angered by this and sent Cetus a sea serpent to kill Andromeda. Cetus destroyed everything in his path as he searched the lands for Andromeda. It was told that the only way to stop Cetus was to sacrifice Andromeda so she was chained naked to a rock.
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