Sanduleak -69 202 (Sk -69 202, also known as GSC 09162-00821) was a magnitude 12 blue supergiant star, located on the outskirts of the Tarantula Nebula in the Large Magellanic Cloud. It was the progenitor of supernova 1987A.

Sanduleak -69 202

SN 1987A was caused by the explosion of Sanduleak -69 202.
Observation data
Epoch J2000      Equinox J2000
Constellation Dorado
Right ascension 05h 35m 27.92s[1]
Declination −69° 16′ 11.1″[1]
Characteristics
Spectral type B3 Ia[2]
Astrometry
Distance168,000 ly
(51,400[1] pc)
Details
Mass~20[2] M
Radius41.15[2] R
Luminosity~100,000[2] L
Temperature16,000[2] K
Other designations
Sk -69 202, GSC 09162-00821
Database references
SIMBADdata

The star was originally charted by the Romanian-American astronomer Nicholas Sanduleak in 1970, but was not well studied until identified as the star that exploded in the first naked eye supernova since the invention of the telescope,[1] when its maximum reached visual magnitude +2.8.[3]

The discovery that a blue supergiant was a supernova progenitor contradicted the prevailing theories of stellar evolution and produced a flurry of new ideas about how such a thing might happen,[4] but it is now accepted that blue supergiants are a normal progenitor for some supernovae.[5]

The candidate luminous blue variable HD 168625 possesses a bipolar nebula that is a close twin of that around Sk -69 202. It is speculated that Sk -69 202 may have been a luminous blue variable in the recent past, although it was apparently a normal luminous supergiant at the time it exploded.[2]

See also

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References

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  1. ^ a b c d Sanduleak, N. (1970). "A deep objective-prism survey for Large Magellanic Cloud members". Contribution. 89. Bibcode:1970CoTol..89.....S.
  2. ^ a b c d e f Smith, N. (2007). "Discovery of a Nearby Twin of SN 1987A's Nebula around the Luminous Blue Variable HD 168625: Was Sk -69 202 an LBV?". The Astronomical Journal. 133 (3): 1034–1538. arXiv:astro-ph/0611544. Bibcode:2007AJ....133.1034S. doi:10.1086/510838. S2CID 17598600.
  3. ^ "SN 1987A". The International Variable Star Index. AAVSO – American Association of Variable Star Observers. Retrieved August 19, 2019.
  4. ^ Podsiadlowski, P. (1992). "The progenitor of SN 1987 A". Publications of the Astronomical Society of the Pacific. 104: 717. Bibcode:1992PASP..104..717P. doi:10.1086/133043.
  5. ^ Georgy, C.; Meynet, G.; Walder, R.; Folini, D.; Maeder, A. (2009). "The different progenitors of type Ib, Ic SNe, and of GRB". Astronomy and Astrophysics. 502 (2): 611. arXiv:0906.2284. Bibcode:2009A&A...502..611G. doi:10.1051/0004-6361/200811339. S2CID 1660838.