Movatterモバイル変換


[0]ホーム

URL:


Jump to content
WikipediaThe Free Encyclopedia
Search

Omicron Hydrae

From Wikipedia, the free encyclopedia
Blue-hued star in the constellation Hydra
Omicron Hydrae
Location of ο Hydrae (circled in red)
Observation data
EpochJ2000.0      EquinoxJ2000.0 (ICRS)
ConstellationHydra[1]
Right ascension11h 40m 12.78970s[2]
Declination−34° 44′ 40.7733″[2]
Apparent magnitude (V)4.70[3]
Characteristics
Spectral typeB9 V[4]
U−Bcolor index−0.20[3]
B−Vcolor index−0.08[3]
Astrometry
Radial velocity (Rv)+5.9[5] km/s
Proper motion (μ)RA: −43.24[2]mas/yr
Dec.: −1.61[2]mas/yr
Parallax (π)7.27±0.16 mas[2]
Distance449 ± 10 ly
(138 ± 3 pc)
Absolute magnitude (MV)−0.99[1]
Details
Mass3.56±0.04[6] M
Radius5.5[7] R
Luminosity309[6] L
Surface gravity (log g)2.87[8] cgs
Temperature10,495[6] K
Rotation27.2 days[8]
Rotational velocity (v sin i)160[6] km/s
Age252[9] Myr
Other designations
ο Hya,CD−34°7610,FK5 439,HD 101431,HIP 56922,HR 4494,SAO 202695[10]
Database references
SIMBADdata

Omicron Hydrae (ο Hya) is theBayer designation for a solitary[11]star in the equatorialconstellationHydra. At one time it bore theFlamsteed designation25 Crateris, but this is no longer used by astronomers so as to avoid confusion.[12] With anapparent visual magnitude of 4.70,[3] this star is visible to the naked eye. Based upon an annualparallax shift of 7.27 mas,[2] it is located around 449 light years from theSun.

This is aB-type main sequence star with astellar classification of B9 V.[4] It has completed an estimated98.4%±1.1% of its lifetime on themain sequence. With 3.56[6] times themass of the Sun, it radiates 309 times theSun's luminosity from itsouter atmosphere at aneffective temperature of 10,495 K.[6] The rate of spin is relatively high, with aprojected rotational velocity of 160 km/s.[6]

References

[edit]
  1. ^abAnderson, 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. XHIP record for this object atVizieR.
  2. ^abcdefvan 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.
  3. ^abcdMermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)",Catalogue of Eggen's UBV Data,SIMBAD,Bibcode:1986EgUBV........0M.
  4. ^abHouk, N. (1982),Michigan Catalogue of Two-dimensional Spectral Types for the HD stars, vol. 3, Ann Arbor, MI: Department of Astronomy, University of Michigan,Bibcode:1982mcts.book.....H.
  5. ^Wielen, R.; et al. (2000), "Sixth Catalogue of Fundamental Stars (FK6). Part III. Additional fundamental stars with direct solutions",Veröffentlichungen Astronomisches Rechen-Institut Heidelberg, vol. 37, no. 37, Karlsruhe: Verlag G. Braun, pp. 1–308,Bibcode:2000VeARI..37....1W,ISBN 3-7650-0536-3.{{citation}}: CS1 maint: work parameter with ISBN (link)
  6. ^abcdefgZorec, 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,S2CID 55586789.
  7. ^Stassun, Keivan G.; et al. (2019), "The Revised TESS Input Catalog and Candidate Target List",The Astronomical Journal,158 (4): 138,arXiv:1905.10694,Bibcode:2019AJ....158..138S,doi:10.3847/1538-3881/ab3467.
  8. ^abOelkers, Ryan J.; Rodriguez, Joseph E.; Stassun, Keivan G.; Pepper, Joshua; Somers, Garrett; Kafka, Stella; Stevens, Daniel J.; Beatty, Thomas G.; Siverd, Robert J.; Lund, Michael B.; Kuhn, Rudolf B.; James, David; Gaudi, B. Scott (2018), "Variability Properties of Four Million Sources in the TESS Input Catalog Observed with the Kilodegree Extremely Little Telescope Survey",The Astronomical Journal,155 (1): 39,arXiv:1711.03608,Bibcode:2018AJ....155...39O,doi:10.3847/1538-3881/aa9bf4.
  9. ^Gontcharov, G. A. (2012), "Dependence of kinematics on the age of stars in the solar neighborhood",Astronomy Letters,38 (12): 771,arXiv:1606.08814,Bibcode:2012AstL...38..771G,doi:10.1134/S1063773712120031.
  10. ^"* omi Hya".SIMBAD.Centre de données astronomiques de Strasbourg. Retrieved2017-01-06.
  11. ^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,S2CID 14878976.
  12. ^Wagman, M. (August 1987), "Flamsteed's Missing Stars",Journal for the History of Astronomy,18 (3): 216,Bibcode:1987JHA....18..209W,doi:10.1177/002182868701800305,S2CID 118445625.
Stars
Bayer
Flamsteed
Variable
HR
HD
Other
Exoplanets
Star clusters
Nebulae
Galaxies
Messier
NGC
Other
Galaxy clusters
Astronomical events
Retrieved from "https://en.wikipedia.org/w/index.php?title=Omicron_Hydrae&oldid=1333614237"
Categories:
Hidden categories:

[8]ページ先頭

©2009-2026 Movatter.jp