M31-RV

M31-RV is a possible red cataclysmic variable star located in the Andromeda Galaxy (M31) that experienced an outburst in 1988,^[4] which was similar to the outburst V838 Monocerotis experienced in 2002.^[3] At peak brightness, M31-RV was the most luminous red supergiant in the Local Group.^[4] Such objects have been called luminous red novae or intermediate-luminosity red transients. During the outburst, both V838 Mon and M31-RV reached a maximum absolute visual magnitude of -9.8.^[1]

M31-RV

Light curves for M31-RV, adapted from Boschi and Munari (2004).[1] The red dots show the red band magnitude, and the blue dots show the blue band magnitude.
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Andromeda
Right ascension	00h 43m 02.433s[2]
Declination	41° 12′ 56.17″[2]
Characteristics
Evolutionary stage	M supergiant[1]
Spectral type	M0I-M7I[1]
Variable type	Luminous Red Nova
Details
Radius	2,000[3] R☉
Luminosity	900,000[3][a] L☉
Temperature	4,000[3] K
Other designations
M31 V1006, M31 V1007, McD 88 1
Database references
SIMBAD	data

In 2006, the area around M31-RV was observed using the Hubble Space Telescope, but only red giants were seen. Most likely the star either became too dim for Hubble to see, the star is a companion of one of the red giants, or the star is one of the red giants themselves.^[2]

M31-RV reached a peak visual magnitude of 17 before fading rapidly and showing dust formation. The most likely explanation states that these outbursts occur during stellar merger events.^[5]

See also

• Astronomy portal

• AE Andromedae

Notes

1. Calculated using the Stefan-Boltzmann Law using the given values for radius and temperature in the reference

References

1. Boschi, F.; Munari, U. (2004). "M 31-RV evolution and its alleged multi-outburst pattern". Astronomy and Astrophysics. 418 (3): 869–875. arXiv:astro-ph/0402313. Bibcode:2004A&A...418..869B. doi:10.1051/0004-6361:20035716. S2CID 18582562.
2. Bond, Howard E. (2011). "Hubble Space Telescope Imaging of the Outburst Site of M31 RV. II. No Blue Remnant in Quiescence". The Astrophysical Journal. 737 (1): 17. arXiv:1105.4595. Bibcode:2011ApJ...737...17B. doi:10.1088/0004-637X/737/1/17. S2CID 118561097.
3. Evans, A.; Geballe, T. R.; Rushton, M. T.; Smalley, B.; van Loon, J. T.; Eyres, S. P. S.; Tyne, V. H. (2003-08-11). "V838 Mon: an L supergiant?". Monthly Notices of the Royal Astronomical Society. 343 (3): 1054–1056. Bibcode:2003MNRAS.343.1054E. doi:10.1046/j.1365-8711.2003.06755.x. ISSN 0035-8711.
4. Rich, R. Michael; Mould, Jeremy; Picard, Alain; Frogel, Jay A.; Davies, Roger (June 1989). "Luminous M Giants in the Bulge of M31". Astrophysical Journal Letters. 341: L51. doi:10.1086/185455. Retrieved 10 October 2024.
5. Kochanek, C. S.; Adams, Scott M.; Belczynski, Krzysztof (2014). "Stellar mergers are common". Monthly Notices of the Royal Astronomical Society. 443 (2): 1319. arXiv:1405.1042. Bibcode:2014MNRAS.443.1319K. doi:10.1093/mnras/stu1226. S2CID 118617376.