Beta Andromedae: Wikis


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β Andromedae
Andromeda constellation map (1).png
β Andromedae is left of center
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Andromeda
Right ascension 01h 09m 43.9236s[1]
Declination +35° 37′ 14.008″[1]
Apparent magnitude (V) 2.01 to 2.10[2]
Spectral type M0III[1]
U-B color index +1.96[3]
B-V color index +1.58[3]
V-R color index 0.9[1]
R-I color index +1.00[3]
Variable type Semiregular[2]
Radial velocity (Rv) 0.3 ± 0.9[1] km/s
Proper motion (μ) RA: 175.59[1] mas/yr
Dec.: −112.23[1] mas/yr
Parallax (π) 16.36 ± 0.76[1] mas
Distance 199 ± 9 ly
(61 ± 3 pc)
Absolute magnitude (MV) −1.9[4]
Mass 3–4[5] M
Radius 90[5] R
Luminosity 1,900[5] L
Temperature 3,800[5] K
Other designations
Mirach, Merach, Mirac, Mizar, β And, Beta Andromedae, Beta And, 43 Andromedae, 43 And, BD+34°198, FK5 42, GJ 53.3, GJ 9044, HD 6860, HIP 5447, HR 337, LTT 10420, NLTT 3848, SAO 54471, WDS 01097+3537A.[1][6]
Database references

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, Mirak).[6] It has spectral class M0, and is approximately 200 light years away.[1] It is classified as a suspected semiregular variable star whose apparent visual magnitude varies from +2.01 to +2.10.[2]



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. The galaxy NGC 404, also known as Mirach's Ghost, is visible seven arc-minutes away.[7]

Naming and etymology

The name Mirach, and its variations, such as Mirac, Mirar, Mirath, Mirax, etc. (the name is spelled Merach in Burritt's The Geography of the Heavens)[8] come from the star's description in the Alfonsine Tables of 1521 as super mizar.[6] Here, mirat is a corruption of the Arabic ميزر mīzar "girdle", which appeared in a Latin translation of the Almagest.[6] This word refers to Mirach's position at the left hip of the princess Andromeda.[9]

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 (Arabian lunar mansion) Batn al-Hũt, the Belly of the Fish, or Qalb al-Hũt, the Heart of the Fish.[6][10] The star has also been called Cingulum and Ventrale.[6]

This al-Hũt was an indigenous Arabic constellation, not the Western "Northern Fish" part of the constellation Pisces.[10]

These names are not from the Arabic marãqq, loins, because it was never called al-Marãqq in Arabian astronomy.[10]

Al Rishã', the Cord (of the well-bucket), on al-Sũfĩ's star map. It is origin of the proper name Alrescha for Alpha Piscium.[6][11][12]

Notes and references

  1. ^ a b c d e f g h i j NAME MIRACH -- Variable Star, database entry, SIMBAD. Accessed on line August 12, 2008.
  2. ^ a b c NSV 414, database entry, table of suspected variable stars, Combined General Catalog of Variable Stars (GCVS4.2, 2004 Ed.), N. N. Samus, O. V. Durlevich, et al., CDS ID II/250.
  3. ^ a b c HR 337, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line August 12, 2008.
  4. ^ From apparent magnitude and parallax.
  5. ^ a b c d Mirach, Stars, Jim Kaler. Accessed on line August 13, 2008.
  6. ^ a b c d e f g Richard Hinckley Allen (1899) Star-names and Their Meanings, p. 36.
  7. ^ Mirach's Ghost (NGC 404), The Internet Encyclopedia of Science, David Darling. Accessed on line August 15, 2008.
  8. ^ p. 18, The Geography of the Heavens, Elijah Hinsdale Burritt, Hiram Mattison, and Henry Whitall, New York: Sheldon & Company, 1856.
  9. ^ Mirach, MSN Encarta. Accessed on line August 19, 2008. Archived 2009-10-31.
  10. ^ a b c George A.Davis Jr. (1971) Selected List of Star Names, p. 5.
  11. ^ ibid. p. 19.
  12. ^ Kunitsch, P., Smart, T., (2006) A Dictionary of Modern Star names: A Shoert Guide to 254 Star Names and Their Derivations, Cambridge, Sky Publishing Corp., p. 50.

Further reading and external links

  • Allen, R. H., (1899) Star Names and Their Meanings, New York: G. E. Stechert
  • Davis Jr., G. A., (1971) Pronunciations, Derivations, and Meanings of a Selected List of Star Names, (rep.) Cambridge, Sky Publishing Corp.
  • Kunitzsch, P., (1959) Arabische Sternnamen in Europa
  • Kunitzsch. P., (ed.) (1990) Der Sternkatalog des Almagest, Band II

Coordinates: Sky map 01h 09m 43.9236s, +35° 37′ 14.008″



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