Omicron Hydrae

Omicron Hydrae
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Hydra
Right ascension	11h 40m 12.78970s[1]
Declination	−34° 44′ 40.7733″[1]
Apparent magnitude (V)	4.70[2]
Characteristics
Spectral type	B9 V[3]
U−B color index	−0.20[2]
B−V color index	−0.08[2]
Astrometry
Radial velocity (Rv)	+5.9[4] km/s
Proper motion (μ)	RA: −43.24[1] mas/yr ; Dec.: −1.61[1] mas/yr
Parallax (π)	7.27 ± 0.16[1] mas
Distance	449 ± 10 ly ; (138 ± 3 pc)
Absolute magnitude (MV)	−0.99[5]
Details[6]
Mass	3.56±0.04 M☉
Luminosity	309 L☉
Temperature	10,495 K
Rotational velocity (v sin i)	160 km/s
Other designations
	ο Hya, CD−34° 7610, FK5 439, HD 101431, HIP 56922, HR 4494, SAO 202695.[7]
Database references
SIMBAD	data

Omicron Hydrae (ο Hya) is the Bayer designation for a solitary[8] star in the equatorial constellation Hydra. At one time it bore the Flamsteed designation 25 Crateris, but this is no longer used by astronomers so as to avoid confusion.[9] With an apparent visual magnitude of 4.70,[2] this star is visible to the naked eye. Based upon an annual parallax shift of 7.27 mas,[1] it is located around 449 light years from the Sun.

This is a B-type main sequence star with a stellar classification of B9 V.[3] It has completed an estimated 98.4%±1.1% of its lifetime on the main sequence. With 3.56[6] times the mass of the Sun, it radiates 309 times the Sun's luminosity from its outer atmosphere at an effective temperature of 10,495 K.[6] The rate of spin is relatively high, with a projected rotational velocity of 160 km/s.[6]

References

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.
Mermilliod, J.-C. (1986), Compilation of Eggen's UBV data, transformed to UBV (unpublished), SIMBAD, Bibcode:1986EgUBV........0M.
Houk, N. (1982), Michigan Catalogue of Two-dimensional Spectral Types for the HD stars, 3, Ann Arbor, MI: Department of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
Wielen, R.; et al. (2000), "Sixth Catalogue of Fundamental Stars (FK6). Part III. Additional fundamental stars with direct solutions", Veröffentlichungen Astronomisches Rechen-Institut Heidelberg, Karlsruhe: Verlag G. Braun (37), pp. 1–308, Bibcode:2000VeARI..37....1W, ISBN 3-7650-0536-3.
Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015.
Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691.
"* omi Hya". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-01-06.
Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.
Wagman, M. (August 1987), "Flamsteed's Missing Stars", Journal for the History of Astronomy, 18: 216, Bibcode:1987JHA....18..209W, doi:10.1177/002182868701800305.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.

[vanLeeuwen2007-1] 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.

[Mermilliod1986-2] Mermilliod, J.-C. (1986), Compilation of Eggen's UBV data, transformed to UBV (unpublished), SIMBAD, Bibcode:1986EgUBV........0M.

[Houk1982-3] Houk, N. (1982), Michigan Catalogue of Two-dimensional Spectral Types for the HD stars, 3, Ann Arbor, MI: Department of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.

[fk6_3-4] Wielen, R.; et al. (2000), "Sixth Catalogue of Fundamental Stars (FK6). Part III. Additional fundamental stars with direct solutions", Veröffentlichungen Astronomisches Rechen-Institut Heidelberg, Karlsruhe: Verlag G. Braun (37), pp. 1–308, Bibcode:2000VeARI..37....1W, ISBN 3-7650-0536-3.

[Anderson2012-5] Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015.

[Zorec2012-6] Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691.

[SIMBAD-7] "* omi Hya". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-01-06.

[Eggleton2008-8] Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.

[Wagman1987-9] Wagman, M. (August 1987), "Flamsteed's Missing Stars", Journal for the History of Astronomy, 18: 216, Bibcode:1987JHA....18..209W, doi:10.1177/002182868701800305.