HD 36960

Last updated
HD 36960
Orion constellation map.svg
Red circle.svg
Location of HD 36960 (circled)
Observation data
Epoch 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
(approx. 500  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 [Fe/H]0.20 [5]   dex
Rotational velocity (v sin i)28 [4]  km/s
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 i Orionis towards the bottom right of the image. The Orion Nebula M42.jpg
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] All these stars are likely members of 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.

References

  1. 1 2 3 4 5 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.
  2. 1 2 3 Reed, B. Cameron (2003). "Catalog of Galactic OB Stars". The Astronomical Journal. 125 (5): 2531–2533. Bibcode:2003AJ....125.2531R. doi: 10.1086/374771 .
  3. 1 2 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.
  4. 1 2 3 4 5 6 7 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.
  5. 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.
  6. 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 .