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Omicron Geminorum

Omicron Geminorum (ο Geminorum, abbreviated Omicron Gem, ο Gem), also named Jishui,[8] is a solitary[9] star in the constellation of Gemini. It is faintly visible to the naked eye with an apparent visual magnitude of 4.90.[2] Based upon an annual parallax shift of 19.3 mas, it is located at a distance of 169 light-years from the Sun.

Nomenclature

ο Geminorum (Latinised to Omicron Geminorum) is the star's Bayer designation.

The star bore the traditional Chinese name of Jishui,[10] meaning a store of water; this name has also been applied to Lambda Persei.[11] In 2016, the IAU organized a Working Group on Star Names (WGSN)[12] to catalog and standardize proper names for stars. The WGSN approved the name Jishui for this star on 30 June 2017 and it is now so included in the List of IAU-approved Star Names.[8]

It was also known to be part of a much bigger constellation named Telescopium Herschelii before it was unrecognized by the International Astronomical Union (IAU).

Properties

The spectral classification of F5-6 IV, suggests that Omicron Geminorum is a subgiant, but evolutionary models indicate that it is still approaching the end of its main sequence life.[1] The measured angular diameter is 0.68±0.03 mas,[13] which, at its estimated distance, yields a physical size of about 3.8 times the radius of the Sun. It radiates approximately 24 times the solar luminosity from an outer atmosphere at an effective temperature of 6,470 K.

References

  1. ^ a b c d e f g h i j k l m 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. ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
  3. ^ McGahee, Courtney; Gray, Richard O.; Griffin, R. E. M.; Birchard, Mariah; Day, Jared (2020), "A Spectroscopic Classification Survey to Search for New ρ Puppis Stars", The Astronomical Journal, 160 (1): 52, Bibcode:2020AJ....160...52M, doi:10.3847/1538-3881/ab974c.
  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, vol. 37, no. 37, Karlsruhe: Verlag G. Braun, pp. 1–308, Bibcode:2000VeARI..37....1W, ISBN 3-7650-0536-3.
  5. ^ a b Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID 118577511.
  6. ^ Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo", Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377.
  7. ^ "* omi Gem", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2016-12-07.
  8. ^ a b "Naming Stars". IAU.org. Retrieved 16 December 2017.
  9. ^ 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.
  10. ^ "WG Triennial Report (2015-2018) - Star Names" (PDF). p. 7. Retrieved 2018-07-14.
  11. ^ IAU Catalog of Star Names, retrieved 22 February 2025.
  12. ^ "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
  13. ^ Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.