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Star in the constellation Orion
HD 36960
Location of HD 36960 (circled)
Observation dataEpoch J2000.0 Equinox J2000.0
Constellation
Orion
Right ascension 5h 35m 02.68074s [ 1]
Declination
−06° 00′ 07.3036″[ 1]
Apparent magnitude (V)4.72[ 2]
Characteristics
Spectral type
B0.5 V[ 3]
U−B color index
−0.98[ 2]
B−V color index
−0.22[ 2]
Astrometry Radial velocity (Rv )+27.7 km/s Proper motion (μ) RA: −0.66[ 1] mas /yr Dec.: +0.01[ 1] mas /yr Parallax (π)2.02 ± 0.31 mas [ 1] Distance approx. 1,600 ly pc ) Absolute magnitude (MV )−3.18[ 4] Details Mass 15.66[ 3] M ☉ Radius 5.6[ 4] R ☉ Luminosity 19,952[ 4] L ☉ Surface gravity (log g )4.10[ 4] cgs Temperature 29,000[ 4] K Metallicity −0.20[ 5] dex Rotational velocity (v sin i )28[ 4] Age 6[ 4] Myr Other designations HD 36960,
HR 1887,
HIP 26199, IRAS 05325-0602,
BD −06°1234,
2MASS J05350268-0600074,
CCDM J05350-0600A,
WDS J05350-0600A
Database references SIMBAD data
HD 36960 is the brighter member of the close pair to the right of ι Orionis towards the bottom right of the image. HD 36960 (HR 1887 ) is a B-type main-sequence star in the constellation Orion . At an apparent magnitude of +4.78 it is easily visible to the naked eye in many areas, though in most urban areas it cannot be seen due to light pollution . Although it does not have a Bayer or Flamsteed designation , it is brighter than over 30 Flamsteed stars in Orion, as well as being brighter than any of the stars in the nearby Orion Nebula such as θ1 Orionis C and θ2 Orionis .
HD 36960 forms a close pair with the slightly fainter HD 36959 36" away. Multiple star catalogues also list the 9th magnitude BD-06°1233 as part of the system. HD 36959 is itself a very close binary with a 9th magnitude companion.[ 6] open cluster NGC 1980 which includes ι Orionis 7' away.
At over 15 solar masses , it shines with around 20,000 times the Sun's luminosity due to its high surface temperature of 29,000 K and radius over five times that of the sun. It is calculated to be around six million years old, consistent with other stars thought to be members of NGC 1980.
^ a b c d e Van Leeuwen, F. (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 . S2CID 18759600 . ^ a b c Reed, B. Cameron (2003). "Catalog of Galactic OB Stars" . The Astronomical Journal . 125 (5): 2531–2533. Bibcode :2003AJ....125.2531R . doi :10.1086/374771 ^ a b Hohle, M. M.; Neuhäuser, R.; Schutz, B. F. (2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten . 331 (4): 349. arXiv :1003.2335 Bibcode :2010AN....331..349H . doi :10.1002/asna.200911355 . S2CID 111387483 . ^ a b c d e f g Nieva, María-Fernanda; Przybilla, Norbert (2014). "Fundamental properties of nearby single early B-type stars". Astronomy & Astrophysics . 566 : A7. arXiv :1412.1418 Bibcode :2014A&A...566A...7N . doi :10.1051/0004-6361/201423373 . S2CID 119227033 . ^ Nieva, M.-F.; Przybilla, N. (2012). "Present-day cosmic abundances. A comprehensive study of nearby early B-type stars and implications for stellar and Galactic evolution and interstellar dust models". Astronomy & Astrophysics . 539 : A143. arXiv :1203.5787 Bibcode :2012A&A...539A.143N . doi :10.1051/0004-6361/201118158 . S2CID 119206639 . ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog" . The Astronomical Journal . 122 (6): 3466. Bibcode :2001AJ....122.3466M . doi :10.1086/323920
