Merak
Designations
- Bayer: β UMa
- Flamsteed: 48 UMa
- Hipparchos: HIP 53910
Data
- Constellation: Ursa Major
- Apparent Magnitude: 2.37
- Right Ascension (J2000): 11h01m48.92s
- Declination (J2000): +56°23'10".8
- Colour Index (B-V): -0.02
- Distance: 84.50±2.47ly
Description
Like Dubhe (α UMa), this star is of particular importance to amateur astronomers, as it comprises one of the Pointers, an asterism used to locate Polaris (α UMi) and thus the North Celestial Pole as well. A line drawn from Merak through Dubhe and continued northwards will eventually arrive near Polaris. To remember this usage, use the mnemonic, "from Merak, we smoke a Dubhe on the way to Polaris!" Along with Dubhe this star marked one of Hyginus's plough-oxen pulling the cart of Boötes, represented by the other five stars of the Big Dipper.
Nomenclature
Merak
The scientific Arab name for the star was Mirāqq al-Dubb al-Akbar, which was abbreviated to Merak and reapplied as a star name in modern times. In Renaissance times, the title for this star was Mizar, a result of a confusion between the Arabic words mi’zar and mirāqq, both transliterated as mirac, mirach, etc. (see also Mizar (ζ UMa)).