HD 268835

HD 268835 (or R66) (30 SM) is one of two stars that were identified by NASA's Spitzer Space Telescope in the Milky Way's nearest neighbor galaxy, the Large Magellanic Cloud (the other being R 126 or HD 37974), as being circled by monstrous dust disks that are theorised to be the origin of planets.

HD 268835

A visual band light curve for HD 268835, adapted from van Genderen & Sterken (2002)[1]
Observation data Epoch J2000      Equinox J2000
Constellation	Mensa
Right ascension	04h 56m 47.0791s
Declination	−69° 50′ 24.792″
Apparent magnitude (V)	10.6[2]
Characteristics
Spectral type	B8Iae[3]
U−B color index	-0.66[2]
B−V color index	0.14[2]
Variable type	LBV?[2]
Astrometry
Radial velocity (Rv)	278 km/s
Proper motion (μ)	RA: 1.63 mas/yr Dec.: -2.38 mas/yr
Absolute magnitude (MV)	-8.5[2]
Details
Mass	<30[4] M☉
Radius	131[4] R☉
Luminosity	320,000[4] L☉
Temperature	12,000[4] K
Other designations
HD 268835, HIP 22989, CD-70°273
Database references
SIMBAD	data

Significance

Both HD 268835 and HD 37974 are classified as hypergiants, very large and very bright. The dust cloud around them surprised astronomers because stars as big as these were thought to be inhospitable to planet formation as they have very strong winds making it difficult/impossible for the dust clouds to "condense" into planets. "We do not know if planets like those in our solar system are able to form in the highly energetic, dynamic environment of these massive stars, but if they could, their existence would be a short and exciting one" said Charles Beichman, an astronomer at NASA's Jet Propulsion Laboratory and the California Institute of Technology, both in Pasadena, California.^[5]

Artist's impression depicting HD 268835's dust disk compared to the Solar System

The infrared spectrum of HD 268835 compared to that of a multi-component model of the disk composition

References

1. van Genderen, A. M.; Sterken, C. (May 2002). "Light variations of massive stars (alpha Cyg variables). XVIII. The B[e] supergiants S 18 in the SMC and R 66 = HDE 268835 and R 126 = HD 37974 in the LMC" (PDF). Astronomy and Astrophysics. 386: 926–935. Bibcode:2002A&A...386..926V. doi:10.1051/0004-6361:20020360. Retrieved 25 September 2024.
2. Stahl, O.; Wolf, B.; Zickgraf, F.-J.; Leitherer, C.; Bastian, U.; de Groot, M. J. H. (April 1983). "R 66(Aeq) - an LMC B supergiant with a massive cool and dusty wind". Astronomy and Astrophysics. 120 (2): 287–296. Bibcode:1983A&A...120..287S.
3. Kastner, J. H.; Thorndike, S. L.; Romanczyk, P. A.; Buchanan, C. L.; Hrivnak, B. J.; Sahai, R.; Egan, M. (2008). "The Large Magellanic Cloud's Top 250: Classification of the Most Luminous Compact 8 μm Sources in the Large Magellanic Cloud". The Astronomical Journal. 136 (3): 1221–1241. arXiv:astro-ph/0703584. Bibcode:2008AJ....136.1221K. doi:10.1088/0004-6256/136/3/1221. S2CID 117820349.
4. Kastner, J. H.; Buchanan, C. L.; Sargent, B.; Forrest, W. J. (2006). "SpitzerSpectroscopy of Dusty Disks around B[e] Hypergiants in the Large Magellanic Cloud". The Astrophysical Journal. 638 (1): L29–L32. Bibcode:2006ApJ...638L..29K. doi:10.1086/500804.
5. NASA's Spitzer Uncovers Hints of Mega Solar Systems Archived 2016-03-04 at the Wayback Machine, Nasa.gov, accessed 11 Feb 2006

• "HD 268835". SIMBAD. Centre de données astronomiques de Strasbourg.