BD+60°2522

BD+60°2522 is a bright O-type star that has produced the Bubble Nebula (NGC 7635) with its stellar wind. The exact classification of the star is uncertain, with a number of spectral peculiarities and inconsistencies between the appearance of the star itself and the effects on the nearby nebulosity, but it is undoubtedly a highly luminous hot massive star.^[5] Direct spectroscopy yields a spectral class of O6.5 and an effective temperature around 37,500 K. It is a member of the Cassiopeia OB2 stellar association in the Perseus Arm^[7] of the galaxy at about 8,500 light-years' distance.^[8]

BD+60°2522

NGC 7635 surrounding BD+60 2522 Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
Observation data Epoch J2000      Equinox J2000
Constellation	Cassiopeia
Right ascension	23h 20m 44.5135s[1]
Declination	+61° 11′ 40.531″[1]
Apparent magnitude (V)	8.67[2]
Characteristics
Spectral type	O6.5(f)(n)p[3]
U−B color index	−0.62[2]
B−V color index	+0.41[2]
Astrometry
Radial velocity (Rv)	−26[4] km/s
Proper motion (μ)	RA: −2.662[1] mas/yr Dec.: 0.388[1] mas/yr
Parallax (π)	0.3341 ± 0.0152 mas[1]
Distance	9,800 ± 400 ly (3,000 ± 100 pc)
Absolute magnitude (MV)	−5.5[5]
Details[6]
Mass	44 M☉
Radius	15 R☉
Luminosity	398,000 L☉
Temperature	37,500 K
Rotational velocity (v sin i)	178 - 240 km/s
Age	2[7] Myr
Other designations
SAO 20575 IRAS 23185+6055 2MASS J23204452+6111404
Database references
SIMBAD	data

Although BD+60°2522 is around two million years old, the surrounding nebula is apparently only about 40,000 years old. The bubble is expected to be formed as a shock front where the stellar wind meets interstellar material at supersonic speeds. The wind from BD+60°2522 is travelling outwards at 1,800–2,500 km/s, causing the star to lose over a millionth of the mass of the Sun every year.^[7]

References

1. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
2. Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
3. Walborn, Nolan R.; Howarth, Ian D.; Evans, Christopher J.; Crowther, Paul A.; Moffat, Anthony F. J.; St-Louis, Nicole; Fariña, Cecilia; Bosch, Guillermo L.; Morrell, Nidia I.; Barbá, Rodolfo H.; Van Loon, Jacco Th. (2010). "The Onfp Class in the Magellanic Clouds". The Astronomical Journal. 139 (3): 1283. arXiv:1001.4032. Bibcode:2010AJ....139.1283W. doi:10.1088/0004-6256/139/3/1283. S2CID 119297513.
4. Wilson, Ralph Elmer (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W. ISBN 9780598216885. LCCN 54001336.
5. Moore, B. D.; Walter, D. K.; Hester, J. J.; Scowen, P. A.; Dufour, R. J.; Buckalew, B. A. (2002). "Hubble Space Telescope Observations of the Windblown Nebula NGC 7635". The Astronomical Journal. 124 (6): 3313. Bibcode:2002AJ....124.3313M. doi:10.1086/344596. S2CID 117009444.
6. Rauw, G.; De Becker, M.; Vreux, J. -M. (2004). "Line profile variability in the spectra of Oef stars". Astronomy and Astrophysics. 399: 287–296. arXiv:astro-ph/0408253. Bibcode:2003A&A...399..287R. doi:10.1051/0004-6361:20021776.
7. Anand, M. Y.; Kagali, B. A.; Murthy, Jayant (2009). "Study of Bubble nebula using IUE high resolution spectra". Bulletin of the Astronomical Society of India. 37 (1): 1. arXiv:0903.2828. Bibcode:2009BASI...37....1A.
8. Mason, Brian D.; Hartkopf, William I.; Gies, Douglas R.; Henry, Todd J.; Helsel, John W. (2009). "The High Angular Resolution Multiplicity of Massive Stars". The Astronomical Journal. 137 (2): 3358. arXiv:0811.0492. Bibcode:2009AJ....137.3358M. doi:10.1088/0004-6256/137/2/3358. S2CID 119268845.