This galaxy has an estimated mass of around billion solar masses, having around globular clusters. Messier , also designated as NGC , is a barred spiral galaxy located at around 83 million light-years away from us. It is exhibiting a weak inner ring structure around the central bar. This galaxy was discovered in by Pierre Mechain, friend and working colleague of Charles Messier. More satellite galaxies may exist.
M is the brightest galaxy in the M Group, a large group of galaxies located in the constellation of Ursa Major that may contain over 50 galaxies. Messier 97, also known as the Owl Nebula, or NGC , is a planetary nebula located at around 2, light-years away from us. This nebula is around 8, years old. A 16 th magnitude star resides in its center that has reached the turning point of its evolution where it condenses to become a white dwarf. The nebula itself holds around 0.
Its outer radius if around 0. The constellation of Ursa Major is mainly known due to its stars that form the asterisms, the Big Dipper, and the Little Dipper. Megrez is a third magnitude star, while the other six are of magnitude second.
The brightest star in Ursa Major is Alioth , a blue-white star which is times brighter than our Sun. Alioth, designated as Epsilon Ursae Majoris, is the brightest star in Ursa Major, and the brightest of the seven stars of the Big Dipper asterism. Alioth is a blue-white giant or subgiant star with a peculiar spectrum, having calcium K-lines in it.
It is located at 86 light-years from Earth, and it is times brighter than our Sun. Alioth has an apparent magnitude of 1. Alioth, along with Dubhe, and Alkaid, are among the 58 navigational stars selected for celestial navigation. Only the brightest and the most easily recognizable stars are part of this group. It is also a spectroscopic binary star system, being the 33 rd brightest star in the night sky, sharing this title with Mirfak, the brightest star in the constellation of Perseus.
Dubhe, along with Merak, is known as the Pointer Stars which are used to find the north pole star which is currently Polaris. The primary star, Dubhe A, is an orange giant star having an apparent magnitude of 1. Dubhe is located at around light-years away from us, and it is around times brighter than our Sun. It is a bluish-white subgiant star that has exhausted its hydrogen supplies, and thus it has begun to cool down. Merak is located at around Phecda, designated as Gamma Ursae Majoris, is an Ae star, which is surrounded by an envelope of gas that is adding emission lines to its spectrum.
Phecda is the sixth brightest star in Ursa Major, having an apparent magnitude of 2. The star is located at around It is 65 times brighter than our Sun. It is the 11 th brightest star in Ursa Major. Megrez is a hydrogen-fusing dwarf still on the main sequence, located at around Megrez is a young star, having an estimated age of million years. Mizar, also designated as Zeta Ursae Majoris, is a quadruple star system with a combined magnitude of 2.
It is located at around Mizar is the fourth brightest star in Ursa Major. Mizar is M81, M82, and NGC can be seen in this photo view larger version. Ursa Major is the third largest constellation in the sky. It occupies an area of square degrees. Ursa Major is located in the second quadrant of the northern hemisphere. The best time to see this constellation is in the spring.
At this time Ursa Major is high above the north-eastern horizon. The eight neighboring constellations to the Great Bear are Draco to the north and northeast. Canes Venatici to the east and southeast. Coma Berenices to the southeast. Leo and Leo Minor to the south. Lynx to the southwest and Camelopardalis to the northwest. From southern temperate latitudes, the Big Dipper is unable to be seen. However, some of the southern parts of the constellation can be seen.
The Great Bear is one of the oldest constellations in the night sky. It can be dated back up to 13, years. It is mentioned in the Bible and also found in the works of the Greek author Homer. In Greek mythology, the constellation is associated with the myth of Callisto. Callisto was the beautiful nymph who had sworn a vow of chastity to the goddess Artemis. One day Zeus saw the nymph and the two fell in love. Zeus and Callisto had a son named Arcas.
Callisto lived as a bear for 15 years, until she came face to face with her son Arcas. Arcas quickly drew his spear but before he could attack Zeus intervened to prevent disaster. Zeus sent a whirlwind that lifted Callisto and Arcas into the heavens. Callisto became Ursa Major. Among the Greek myths there are different versions of this tale. It has an apparent magnitude of 1. Alioth belongs to the Ursa Major Moving Group Collinder , a group of stars that includes most of the brightest stars in the constellation Ursa Major.
The stars belonging to the group share common velocities in space and are believed to have a common origin. Proctor, who realized that all stars of the Big Dipper with the exception of Alkaid and Dubhe have proper motions heading toward a common point in the constellation Sagittarius. Alioth belongs to the spectral class A0pCr.
Alioth exhibits fluctuations in its spectral lines with a period of 5. Dubhe has an apparent magnitude of 1. It is the second brightest star in Ursa Major. It is a spectroscopic binary star. The companion is a main sequence star that belongs to the spectral type F0 V. It completes the orbit around the brighter star every There is another binary system about 90, AU away from the main pair, which makes Alpha Ursae Majoris a four star system.
Beta Ursae Majoris is a main sequence star, approximately It belongs to the spectral class A1 V. The star has a debris disk of dust orbiting it, one with a mass 0. Beta Ursae Majoris is 2. It belongs to the Ursa Major Moving Group and is a suspected variable star. Alkaid is the easternmost star in the Big Dipper asterism. It is also known as Elkeid and Benetnash. It is a young main sequence star belonging to the spectral class B3 V, approximately light years distant.
Alkaid is notable for being one of the hottest stars that can be seen without binoculars. It has a surface temperature of 20, kelvins. The star has six solar masses and is about times more luminous than the Sun. The name Alkaid itself means leader. Gamma Ursae Majoris is the lower left star in the bowl of the Big Dipper.
It belongs to the Ursa Major Moving Group. Gamma UMa is a main sequence star of the spectral type A0 Ve. It has a visual magnitude of 2. The star is located only 8. Megrez, Delta Ursae Majoris, is the faintest of the seven bright stars that form the Big Dipper asterism. It is a main sequence star of the spectral type A3 V. It has a visual magnitude of 3. The star emits an excess of infrared radiation, which indicates a debris disk in its orbit.
Zeta Ursae Majoris is a system composed of two binary stars. Mizar has an apparent magnitude of 2. It was the first double star ever to be photographed. Early American photographer and inventor John A. Whipple and astronomer George P. Bond took the photo of the binary system in using a wet collodion plate and the inch refractor telescope at Harvard College Observatory. Bond had previously also photographed the star Vega in Lyra constellation in Alcor is a visual companion to Mizar.
It belongs to the spectral class A5V. Alcor has a visual magnitude of 3. Alcor was discovered to be a binary system in The estimated distance between the two stars is 1. It is a binary system composed of two close stars in a circular orbit with a period of 0.
The stars are physically so close that their outer envelopes are in direct contact. The Eddington Limit is a theoretical limit on how bright a star should be for its given mass. It is named after Sir Arthur Eddington who devised the limit in the first part of the twentieth century.
The more norrth you are, the more likely you are to get a good glimpse of this object. In London, you will be able to see this constellation all year round. The worst time is October and November when it is ats lowest in the sky. If you can stay up late, it is best to see about 11pm in May.
May to September provide for a good view about 10 p. The constellation is predominantly a northern hemisphere constellation so if you don't get to see it, you know why. You will not be able to see this constellation if you are in Sydney.
You would need to move a little more north. You are able to see this constellation on the horizon clear from April at about 9 p. If you want to see it earlier, you would need to stay up a little late. The constellation is visible from a north-easterly direction. The constellation will start disappearing in June. Zeus had a son Arcas with Callisto. In a fit of rage, Hera turned Callisto into a bear. When Arcas nearly killed his mother as he didn't know who she was, Zeus turned Arcas into a bear Ursa Minor and sent them to the stars.
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