The star is believed to be about million years old. It has a visual magnitude of 1. Alioth has a mass of 2. It shines with solar luminosities with an effective temperature of about 9, K. Alioth is a peculiar star, one that shows variations in its spectral lines over a period of 5. It is classified as an Alpha 2 Canum Venaticorum variable. It is the brightest of the seven stars in the Big Dipper asterism.
It has an apparent magnitude of 3. Megrez is a white main sequence star of the spectral type A3 V. It has a mass of 1. With a surface temperature of about 9, K, it is 14 times more luminous than the Sun. Like its Big Dipper neighbours, it is believed to be about million years old. The star has a mass 2. It is Phecda has an astrometric binary companion, an orange dwarf of the spectral type K2 V that perturbs it and causes it to wobble around the centre of mass. The two stars have an orbital period of The companion has a mass of 0.
It shines with only 0. It is the second brightest star in Ursa Major. Dubhe is an orange giant with the stellar classification of K0III. It is a spectroscopic binary star, with a white main sequence companion of the spectral type F0V. The two stars are 23 astronomical units apart and have an orbital period of Dubhe is 4. It is a slow spinner, with a projected rotational velocity of 2. The companion is less massive, with about 1. It has a visual magnitude of 4.
It is classified as a suspected variable. 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, are 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. Dubhe is situated in the bowl of the Big Dipper asterism. It is a bluish-white subgiant star that has exhausted its hydrogen supplies, and thus it has begun to cool down.
Merak is one of the four stars which form the bowl of the Big Dipper. 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. Megrez is the 11 th brightest star in Ursa Major, the upper left star of the Big Dipper bowl, connecting the bowl to the handle, formed by the brighter Alioth, Mizar, and Alkaid.
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 It is the fourth brightest star in Ursa Major. Alkaid , designated as Eta Ursae Majoris, is the third brightest star in Ursa Major, and also the 38 th brightest star in the night sky, sharing the title with Sargas. Alkaid is a blue main-sequence star located at around Asterisms are prominent groups of stars that form patterns but are smaller than, or even part of, a constellation.
They are usually easy to find because the stars are close to one another and about the same brightness. In this case, the Big Dipper has eight stars in it. Seven are visible at a glance, while the eighth is a visible double star that is just detectable with the naked eye in an area with clear "seeing" and with good vision. The stars making up the asterism are from the end of the handle and around the bottom of the bowl Alkaid, Mizar-Alcor, Alioth, Megrez, Phecda, Merak and Dubhe.
Mizar and Alcor which is noticeably dimmer are the double forming the second star from the end of the Big Dipper's handle. The system actually contains at least six stars, but only two of them are visible to the naked eye.
According to Rick Raasch of the Texas Astronomical Society , Mizar was the first double star to be discovered through a telescope, in ; the first star to be photographed, in ; and the first star to be identified as a spectroscopic binary, in The comet made its closest approach to Earth in at least 50 years, and possibly , NASA said in a statement at the time. In , the star 47 Ursae Majoris — which likely hosts three exoplanets — was renamed Chalawan in a contest hosted by the International Astronomical Union, as a part of its NameExoWorlds contest.
Chalawan is a Thai name for crocodile, and it is the name by which Thai culture refers to the Big Dipper. The Big Dipper was imaged from space by the Jupiter-bound Juno spacecraft in in what is likely the farthest photo of the constellation ever taken.
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