Mira

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Mira
Diagram shawin starn poseetions an boundaries o the Cetus constellation an its surroondins
Cercle rouge 100%.svg

Location o Mira (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cetus
Richt ascension 02h 19m 20.79210s[1]
Declination –02° 58′ 39.4956″[1]
Apparent magnitude (V) 3.04[2] (2.0 to 10.1)[3]
Characteristics
Spectral type M7 IIIe[4]
U−B colour index +0.08[5]
B−V colour index +1.53[5]
Variable type Mira
Astrometry
Radial velocity (Rv) +63.8[6] km/s
Proper motion (μ) RA: +9.33[1] mas/yr
Dec.: –237.36[1] mas/yr
Parallax (π) 10.91 ± 1.22[1] mas
Distance approx. 300 ly
(approx. 90 pc)
Details
Mass 1.18[7] M
Radius 332–402[8] R
Luminosity 8,400–9,360[8] L
Temperatur 2918–3192[8] K
Age 6[7] Gyr
Ither designations
Stella Mira, Collum Ceti, Wonderful Starn,[9] Omicron Ceti, 68 Ceti, HR 681, BD −03° 353, HD 14386, LTT 1179, SAO 129825, HIP 10826.[10]

Mira (/ˈmrə/, an aa kent as Omicron Ceti, ο Ceti, ο Cet) is a reid giant starn estimatit 200–400 licht years away in the constellation Cetus. Mira is a binary starn, consisting o the reid giant Mira A alang wi Mira B. Mira A is an aa an oscillatin variable starn an wis the first non-supernova variable starn discovered, wi the possible exception o Algol. Apart frae the unuisual Eta Carinae, Mira is the brichtest periodic variable in the sky that is nae veesible tae the naked ee for pairt o its cycle. Its distance is uncertain; pre-Hipparcos estimates centered aroond 220 licht-years,[11] while Hipparcos data suggest a distance o 418 licht-years, albeit wi a margin o error of ~14%.

References[eedit | eedit soorce]

  1. 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357 
  2. Nicolet, B. (1978). "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System". Astronomy and Astrophysics Supplement Series 34: 1–49. Bibcode:1978A&AS...34....1N. 
  3. Kukarkin, B. V. (1971). "The third edition containing information on 20437 variable stars discovered and designated till 1968". General Catalogue of Variable Stars (3rd ed.). Bibcode:1971GCVS3.C......0K. 
  4. Castelaz, Michael W.; Luttermoser, Donald G. (1997). "Spectroscopy of Mira Variables at Different Phases.". The Astronomical Journal 114: 1584–1591. Bibcode:1997AJ....114.1584C. doi:10.1086/118589. 
  5. 5.0 5.1 Celis S., L. (1982). "Red variable stars. I — UBVRI photometry and photometric properties". Astronomical Journal 87: 1791–1802. Bibcode:1982AJ.....87.1791C. doi:10.1086/113268. 
  6. Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick, Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, Bibcode:1967IAUS...30...57E 
  7. 7.0 7.1 Wyatt, S. P.; Cahn, J. H. (1983). "Kinematics and ages of Mira variables in the greater solar neighborhood". Astrophysical Journal, Part 1 275: 225–239. Bibcode:1983ApJ...275..225W. doi:10.1086/161527. 
  8. 8.0 8.1 8.2 Woodruff, H. C.; Eberhardt, M.; Driebe, T.; Hofmann, K.-H.; Ohnaka, K.; Richichi, A.; Schert, D.; Schöller, M.; Scholz, M.; Weigelt, G.; Wittkowski, M.; Wood, P. R. (2004). "Interferometric observations of the Mira star o Ceti with the VLTI/VINCI instrument in the near-infrared" (PDF). Astronomy & Astrophysics 421 (2): 703–714. arXiv:astro-ph/0404248. Bibcode:2004A&A...421..703W. doi:10.1051/0004-6361:20035826. Retrieved 2007-12-07. 
  9. Allen, Richard H. (1963). Star Names: Their Lore and Meaning. New York: Dover Publications. ISBN 0-486-21079-0. 
  10. "V* omi Cet -- Variable Star of Mira Cet type". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2006-08-10. 
  11. Burnham, Jr., Robert (1980), Burnham's Celestial Handbook 1, New York: Dover Publications Inc., p. 634