HD 22764, also known as HR 1112, is an orange hued star located in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.78,[2] allowing it to be faintly visible to the naked eye. The object is located relatively far at a distance of approximately 1,770 light years based on Gaia DR3 parallax measurements[1] but is approaching the Solar System with a heliocentric radial velocity of −12.5 km/s.[4] At its current distance, HD 22764's brightness is diminished by 0.66 magnitudes due to interstellar dust.[5]

HD 22764
Location of HD 22764 on the map (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Camelopardalis
Right ascension 03h 42m 42.73699s[1]
Declination +59° 58′ 09.8029″[1]
Apparent magnitude (V) 5.78[2]
Characteristics
Spectral type K3.5 IIIb + G[3]
U−B color index +1.78[2]
B−V color index +1.76[2]
R−I color index +1.02[2]
Astrometry
Radial velocity (Rv)−12.53±0.26[4] km/s
Proper motion (μ) RA: −2.124 mas/yr[1]
Dec.: +2.342 mas/yr[1]
Parallax (π)1.8433 ± 0.0671 mas[1]
Distance1,770 ± 60 ly
(540 ± 20 pc)
Absolute magnitude (MV)−4.47[5]
Absolute bolometric
magnitude
 (Mbol)
−4.52±0.30[6]
Details
Mass2.86[7] or 6.8±1[8] M
Radius167±8[9] R
Luminosity3,342±221[10] L
Surface gravity (log g)1.08 or 1.41[11] cgs
Temperature3,928±170[6] K
Metallicity [Fe/H]−0.19[12] dex
Rotational velocity (v sin i)<1.9[13] km/s
Age820[7] or 47±8[8] Myr
Other designations
AG+59°378, BD+59°699, HD 22764, HIP 17342, HR 1112, SAO 24169, WDS J03427+5958A[14]
Database references
SIMBADdata

The object has two stellar classifications; one states that it is an ageing red giant (K3.5 IIIb)[3] while the other instead lists it as a slightly cooler lower luminosity red supergiant (K4 Ib).[15] The first spectrum hints a close companion to the object of spectral type G. If considered as a supergiant, it has 6.8 times the mass of the Sun;[8] if considered as an older giant star, it has a mass of 2.86 M.[7] As a result of its evolved state, HD 22764 has expanded to 167 times the Sun's radius[9] and now radiates 3,342 times the luminosity of the Sun[10] from its photosphere at an effective temperature of 3,928 K.[6] Age estimates range from 47 up to 820 million years.[7][8] It has an iron abundance 65% that of the Sun,[12] making it metal deficient. The object spins leisurely with a projected rotational velocity lower than 1.9 km/s.[13]

HD 22764 is the primary of a binary star[16] consisting of it and HD 22763, a B8 giant star located 54.8" away along a position angle of 38°. There are also 4 line-of-sight companions located near the system.[17]

References

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  1. ^ a b c d e 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 e Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". VizieR Online Data Catalog. 2237. Bibcode:2002yCat.2237....0D.
  3. ^ a b Keenan, Philip C.; McNeil, Raymond C. (October 1989). "The Perkins catalog of revised MK types for the cooler stars". The Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373. eISSN 1538-4365. ISSN 0067-0049.
  4. ^ a b Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (January 2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430: 165. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. S2CID 17804304.
  5. ^ a b Mel'nik, A. M.; Dambis, A. K. (30 August 2017). "Kinematics of OB-associations in Gaia epoch". Monthly Notices of the Royal Astronomical Society. 472 (4): 3887–3904. arXiv:1708.08337. Bibcode:2017MNRAS.472.3887M. doi:10.1093/mnras/stx2225. eISSN 1365-2966. ISSN 0035-8711.
  6. ^ a b c Messineo, M.; Brown, A. G. A. (18 June 2019). "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. eISSN 1538-3881.
  7. ^ a b c d Bertelli, G.; Bressan, A.; Chiosi, C.; Fagotto, F.; Nasi, E. (August 1994). "Theoretical isochrones from models with new radiative opacities". Astronomy and Astrophysics Supplement Series. 106: 275–302. Bibcode:1994A&AS..106..275B. ISSN 0365-0138.
  8. ^ a b c d Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (October 12, 2010). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1). Oxford University Press (OUP): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. ISSN 0035-8711.
  9. ^ a b Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants". Astronomy & Astrophysics. 426 (1): 297–307. arXiv:astro-ph/0404180. Bibcode:2004A&A...426..297K. doi:10.1051/0004-6361:20035930. eISSN 1432-0746. ISSN 0004-6361.
  10. ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  11. ^ Luck, R. Earle (25 August 2015). "Abundances in the Local Region. I. G and K Giants". The Astronomical Journal. 150 (3): 88. arXiv:1507.01466. Bibcode:2015AJ....150...88L. doi:10.1088/0004-6256/150/3/88. eISSN 1538-3881. ISSN 0004-6256. S2CID 118505114.
  12. ^ a b Luck, R. Earle (2 May 2014). "Parameters and Abundances in Luminous Stars". The Astronomical Journal. 147 (6): 137. Bibcode:2014AJ....147..137L. doi:10.1088/0004-6256/147/6/137. eISSN 1538-3881. ISSN 0004-6256.
  13. ^ a b De Medeiros, J. R.; Udry, S.; Burki, G.; Mayor, M. (29 October 2002). "A catalog of rotational and radial velocities for evolved stars". Astronomy & Astrophysics. 395 (1): 97–98. Bibcode:2002A&A...395...97D. doi:10.1051/0004-6361:20021214. eISSN 1432-0746. ISSN 0004-6361.
  14. ^ "HD 22764". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved December 16, 2022.
  15. ^ Appenzeller, Immo (April 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. eISSN 1538-3873. ISSN 0004-6280.
  16. ^ Eggleton, P. P.; Tokovinin, A. A. (11 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. eISSN 1365-2966. ISSN 0035-8711.
  17. ^ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.