Astronomy:Omega2 Cygni

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Short description: Star in the constellation Cygnus


Omega2 Cygni
Observation data
Equinox J2000.0]] (ICRS)
Constellation Cygnus[1]
Right ascension  20h 31m 18.81655s[2]
Declination +49° 13′ 13.0638″[2]
Apparent magnitude (V) 5.5292±0.0013[3]
Characteristics
Evolutionary stage AGB[4]
Spectral type M2 III[4]
Astrometry
Radial velocity (Rv)−64.15±0.20[3] km/s
Proper motion (μ) RA: +8.959[2] mas/yr
Dec.: −32.092[2] mas/yr
Parallax (π)7.1833 ± 0.0675[2] mas
Distance454 ± 4 ly
(139 ± 1 pc)
Absolute magnitude (MV)+0.00[1]
Details
Mass1.4[5] M
Radius45[6] R
Luminosity398[6] L
Surface gravity (log g)2.02[5] cgs
Temperature3,920[5] K
Metallicity [Fe/H]−0.10[5] dex
Other designations
ω2 Cyg, 46 Cygni, BD+48°3154, HD 195774, HIP 101243, HR 7851, SAO 49741.[7]
Database references
SIMBADdata

Omega2 Cygni, Latinized from ω2 Cygni, is the Bayer designation for a solitary[8] star in the northern constellation of Cygnus. It has an apparent visual magnitude of 5.5,[3] which is faintly visible to the naked eye on a dark night. Based upon an annual parallax shift of 7.18 mas,[2] it is located roughly 454 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.08 due to interstellar dust.[3]

This is a red giant star on the asymptotic giant branch, with a stellar classification of M2 III.[4] It is a suspected variable star, although the evidence is considered "doubtful or erroneous". If it does exist, the variability is small with an amplitude of 0.05 magnitude and a timescale of around 30 days.[9] There is a 58.3% chance that this star is a member of the Hercules stream.[3]

See also

References

  1. 1.0 1.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A  XHIP record for this object at VizieR.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  3. 3.0 3.1 3.2 3.3 3.4 Famaey, B. et al. (January 2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics 430 (1): 165–186. doi:10.1051/0004-6361:20041272. Bibcode2005A&A...430..165F. 
  4. 4.0 4.1 4.2 Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". Astronomical Journal 104 (1): 275–313. doi:10.1086/116239. Bibcode1992AJ....104..275E. 
  5. 5.0 5.1 5.2 5.3 Khalatyan, A.; Anders, F.; Chiappini, C.; Queiroz, A. B. A.; Nepal, S.; Dal Ponte, M.; Jordi, C.; Guiglion, G. et al. (2024). "Transferring spectroscopic stellar labels to 217 million Gaia DR3 XP stars with SHBoost". Astronomy and Astrophysics 691: A98. doi:10.1051/0004-6361/202451427. Bibcode2024A&A...691A..98K. 
  6. 6.0 6.1 Fetherolf, Tara; Pepper, Joshua; Simpson, Emilie; Kane, Stephen R.; Močnik, Teo; English, John Edward; Antoci, Victoria; Huber, Daniel et al. (2023). "Variability Catalog of Stars Observed during the TESS Prime Mission". The Astrophysical Journal Supplement Series 268 (1): 4. doi:10.3847/1538-4365/acdee5. Bibcode2023ApJS..268....4F. 
  7. "ome02 Cyg". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ome02+Cyg. 
  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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode2008MNRAS.389..869E. 
  9. Percy, John R.; Fleming, David E. B. (February 1992). "A photometric survey of suspected small-amplitude red variables". Publications of the Astronomical Society of the Pacific 104: 96–100. doi:10.1086/132963. Bibcode1992PASP..104...96P.