Beta Andromedae (Beta And / β And / β Andromedae) is a red giant star in the constellation of Andromeda. It has the traditional name Mirach (also spelled Merach, Mirac, and in various other ways.) It has spectral class M0, and is approximately 200 light years away. It is classified as a suspected semiregular variable star whose apparent visual magnitude varies from +2.01 to +2.10.
β Andromedae is located northeast of the Great Square of Pegasus
and is theoretically visible to all observers north of 54° S. Its location in the sky is shown on the left.
NGC 404, also known as Mirach's Ghost
, is visible seven arc-minutes away.
Naming and etymology
The name Mirach
, and its variations, such as Mirac
, etc. (the name is spelled Merach
's The Geography of the Heavens
) come from the star's description in the Alfonsine Tables
of 1521 as super mizar
. Here, mirat
is a corruption of the Arabic mizar
) which appeared in a Latin
translation of the Almagest
. This word refers to Mirach's position at the left hip of the princess Andromeda
Medieval astronomers writing in Arabic called β Andromedae Janb al-Musalsalah (English: The Side of the Chained (Lady)); it was part of the 26th manzil (lunar mansion) Batn al-Hũt, the Belly of the Fish, or Qalb al-Hũt, the Heart of the Fish. The star has also been called Cingulum and Ventrale.
The red giant of spectral class M0 has the multiple star designation WDS
01097+3537A, and has been observed to have a number of visual companions
, shown below. Components B, C, and D are known to be optical.
Notes and references
Further reading and external links
- Allen, R. H., (1899) Star Names and Their Meanings
- Kunitzsch, P., (1959) Arabische Sternnamen in Europa
- Kunitzsch. P., (ed.) (1990) Der Sternkatalog des Almagest, Band II
- Hyde, T., (trans.) (1665) Tabulae Long. ac Lat. Stellarum Fixarum, ex Observatione Ulugh Beighi
- Image MIRACH