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V762 Cassiopeiae

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V762 Cassiopeiae
This is a map that pinpoints V762 Cassiopeiae location.
The location of V762 Cassiopeiae
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cassiopeia[1]
Right ascension 01h 16m 11.902s[2]
Declination +71° 44′ 37.83″[2]
Apparent magnitude (V) 5.82 – 5.95[3]
Characteristics
Evolutionary stage RSG[4] or AGB[5]
Spectral type K5I[4][3] or M3II[6]
Variable type LC[3]
Astrometry
Radial velocity (Rv)−21.37±0.91[2] km/s
Proper motion (μ) RA: −1.658 mas/yr[2]
Dec.: +1.791 mas/yr[2]
Parallax (π)1.3148±0.0693 mas[2]
Distance2,500 ± 100 ly
(760 ± 40 pc)
Details
Mass2.9[7] M☉
Radius265.7[5] R☉
Luminosity14,970[5] L☉
Surface gravity (log g)0.90[7] cgs
Temperature3,869±145[4][5] K
Metallicity [Fe/H]−0.18[7] dex
Age10.0±1.6[8] Myr
Other designations
V762 Cas, BD+70 90, HD 7389, HIP 5926, HR 365, SAO 4358, TYC 4305-2038-1[9]
Database references
SIMBADdata

V762 Cassiopeiae is a cool evolved variable star located about 2,500 light-years away in the Cassiopeia constellation. Its apparent magnitude vary between 5.82 and 5.95, which makes it faintly visible to the naked eye under dark skies. It is a relatively cool star with an average surface temperature of 3,869 K.

Characteristics

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A light curve for V762 Cassiopeiae, plotted from Hipparcos data[10]

V762 Cassiopeiae has a spectral classification of K5 I,[4] suggesting that it is an evolved K-type red supergiant star. Other catalogues have published spectral types of K4,[11] M,[12] and M3II.[6] The Bright Star Catalogue assigned a class of K1V,[13] which originated from one of the earliest observations of this star[14] and was adopted by the General Catalogue of Variable Stars.[13] Recent estimates of the star's physical properties, considering its distance in excess of a thousand light-years,[2] found that it is a red supergiant[4] or asymptotic giant branch star.[5]

At an estimated to be ten million years old,[8] has around 2.9 times the Sun's mass and has expanded to 266 times the Sun's radius. It radiates 15,000 times the solar luminosity from its photosphere at an effective temperature of 3,869 K,[5] which gives it an orange-red hue.[15] Parallax measurements from the Gaia spacecraft show that V762 Cassiopeiae is located about 2,500 light-years away.[2] At the estimated distance, V762 Cassiopeiae's apparent brightness is diminished by 1.04 magnitudes due to interstellar extinction.[5]

Hipparcos satellite data showed that the star is variable, and because of that it was given the variable-star designation V762 Cassiopeiae, in 1999.[16] The variability amplitude in visible light is only about 0.1 magnitudes. The International Variable Star Index lists it as a supergiant slow irregular variable,[3] but the General Catalogue of Variable Stars (GCVS) classifies it as a possible BY Draconis star.[17]

Distance and titleholding

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Some websites claim V762 Cassiopeiae is the "farthest star visible to the naked eye", at a distance of 16,308 light-years.[18][19] This distance is apparently based on the first Hipparcos published parallax of 0.22±0.59 mas, approximately 5,000 pc or 16,308 light years. However, given the statistical margin of error, the distance is meaningless. The Hipparcos new reduction gives a parallax of 1.18±0.45 mas, corresponding to a distance of about 2,800 light-years,[20] and Gaia DR3 lists a parallax of 1.3148±0.0693 mas, corresponding to a distance of about 2,500 light-years.[2]

References

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  1. ^ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
  2. ^ a b c d e f g h 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.
  3. ^ a b c d "V0762 Cas". The International Variable Star Index. AAVSO. Retrieved 8 May 2024.
  4. ^ a b c d e Messineo, M.; Brown, A. G. A. (2019-07-01). "A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2". The Astronomical Journal. 158 (1): 20. arXiv:1905.03744. Bibcode:2019AJ....158...20M. doi:10.3847/1538-3881/ab1cbd. ISSN 0004-6256. V762 Cassiopeiae's database entry at VizieR.
  5. ^ a b c d e f g Healy, Sarah; Horiuchi, Shunsaku; Molla, Marta Colomer; Milisavljevic, Dan; Tseng, Jeff; Bergin, Faith; Weil, Kathryn; Tanaka, Masaomi (2024-03-23). "Red Supergiant Candidates for Multimessenger Monitoring of the Next Galactic Supernova". Monthly Notices of the Royal Astronomical Society. 529 (4): 3630–3650. arXiv:2307.08785. Bibcode:2024MNRAS.529.3630H. doi:10.1093/mnras/stae738. ISSN 0035-8711.
  6. ^ a b Pickles, A.; Depagne, É. (2010). "All-Sky Spectrally Matched UBVRI - ZY and u‧ g‧ r‧ i‧ z‧ Magnitudes for Stars in the Tycho2 Catalog". Publications of the Astronomical Society of the Pacific. 122 (898): 1437. arXiv:1011.2020. Bibcode:2010PASP..122.1437P. doi:10.1086/657947.
  7. ^ a b c Khalatyan, A.; Anders, F.; Chiappini, C.; Queiroz, A. B. A.; Nepal, S.; Dal Ponte, M.; Jordi, C.; Guiglion, G.; Valentini, M.; Torralba Elipe, G.; Steinmetz, M.; Pantaleoni-González, M.; Malhotra, S.; Jiménez-Arranz, Ó.; Enke, H.; Casamiquela, L.; Ardèvol, J. (2024). "Transferring spectroscopic stellar labels to 217 million Gaia DR3 XP stars with SHBoost". Astronomy and Astrophysics. 691: A98. arXiv:2407.06963. Bibcode:2024A&A...691A..98K. doi:10.1051/0004-6361/202451427.
  8. ^ a b Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (2011-01-01). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. ISSN 0035-8711. V762 Cassiopeiae's database entry at VizieR.
  9. ^ "HD 7389". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 9 April 2024.
  10. ^ EAS (1997). "The HIPPARCOS and TYCHO catalogues". Astrometric and Photometric Star Catalogues Derived from the ESA Hipparcos Space Astrometry Mission. ESA SP Series. 1200. Noordwijk, Netherlands: ESA Publications Division. Bibcode:1997ESASP1200.....E. ISBN 9290923997. Retrieved 15 October 2022.
  11. ^ Duflot, M.; Figon, P.; Meyssonnier, N. (1995). "Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue". Astronomy and Astrophysics Supplement Series. 114: 269. Bibcode:1995A&AS..114..269D.
  12. ^ Platais, I.; Pourbaix, D.; Jorissen, A.; Makarov, V. V.; Berdnikov, L. N.; Samus, N. N.; Lloyd Evans, T.; Lebzelter, T.; Sperauskas, J. (2003). "Hipparcos red stars in the HpVT2 and VIC systems". Astronomy and Astrophysics. 397: 997. arXiv:astro-ph/0211048. Bibcode:2003A&A...397..997P. doi:10.1051/0004-6361:20021589.
  13. ^ a b Hoffleit, Dorrit; Jaschek, Carlos (1991). The Bright star catalogue. Bibcode:1991bsc..book.....H.
  14. ^ Appenzeller, Immo (1967). "MK Spectral Types for 185 Bright Stars". Publications of the Astronomical Society of the Pacific. 79 (467): 102. Bibcode:1967PASP...79..102A. doi:10.1086/128449.
  15. ^ "The Colour of Stars". Australia National Telescope Facility. 6 March 2024. Retrieved 2024-05-27.
  16. ^ Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. (January 1999). "The 74th Special Name-list of Variable Stars" (PDF). Information Bulletin on Variable Stars. 4659: 1. Bibcode:1999IBVS.4659....1K. Retrieved 8 May 2024.
  17. ^ "Query= V762 Cas". General Catalogue of Variable Stars. Lomonosov Moscow State University. Retrieved 8 May 2024.
  18. ^ "Farthest Star You Can See With The Unaided Eye". Cosmoknowledge. 2021-03-26. Retrieved 2024-04-11.
  19. ^ "How Far Back In Time Can We See With Our Naked Eye?". Big Think. 2021-05-17. Retrieved 2024-04-11.
  20. ^ "HIP 5926". VizieR. Centre de données astronomiques de Strasbourg. Retrieved 11 April 2024.
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