HD 220105

Summary

HD 220105 is a star in the northern constellation of Andromeda, and a member of the Sirius supercluster.[8] It lies near the lower limit of visibility to the naked eye at an apparent visual magnitude of 6.24, and can be a challenge to spot under normal viewing conditions. The star is located 238 light years away, based upon an annual parallax shift of 13.78 mas. It is moving closer to the Earth with a heliocentric radial velocity of −2 km/s.

HD 220105
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 23h 20m 44.09845s[1]
Declination +44° 06′ 58.1997″[1]
Apparent magnitude (V) 6.24[2]
Characteristics
Spectral type A5 Vn[3]
U−B color index 0.10[2]
B−V color index 0.14[2]
Astrometry
Radial velocity (Rv)−1.8[4] km/s
Proper motion (μ) RA: −9.582[1] mas/yr
Dec.: −37.026[1] mas/yr
Parallax (π)13.7783 ± 0.0277 mas[1]
Distance236.7 ± 0.5 ly
(72.6 ± 0.1 pc)
Details
Mass1.85[5] M
Radius1.8[1] R
Luminosity18.6[1] L
Surface gravity (log g)4.19±0.14[5] cgs
Temperature8,367±284[5] K
Rotational velocity (v sin i)259[6] km/s
Age525[5] Myr
Other designations
BD+43°4440, HD 220105, HIP 115261, HR 8884, SAO 52927, WDS J23207+4407A[7]
Database references
SIMBADdata

This is an A-type main-sequence star with a stellar classification of A5 Vn, where the 'n' notation indicates "nebulous" absorption lines due to rapid rotation. It is around 525 million years old with a high projected rotational velocity of 259 km/s. The star has 1.85 times the mass of the Sun and is radiating 19 times the Sun's luminosity from its photosphere at an effective temperature of 8,367 K.

HD 220105 has a magnitude 10.13 companion located at an angular separation of 13.60 along a position angle of 178°, as of 2015,[9] and it is listed as a close binary by Zorec and Royer (2012).[6] These coordinates are a source for X-ray emission with a luminosity of 1.212×1022 W, which is most likely coming from the faint companion.[10]

References edit

  1. ^ a b c d e f g 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 Oja, T. (August 1991). "UBV photometry of stars whose positions are accurately known. VI". Astronomy and Astrophysics Supplement Series. 89 (2): 415–419. Bibcode:1991A&AS...89..415O.
  3. ^ Cowley, A.; et al. (April 1969). "A study of the bright A stars. I. A catalogue of spectral classifications". Astronomical Journal. 74: 375–406. Bibcode:1969AJ.....74..375C. doi:10.1086/110819.
  4. ^ Kharchenko, N. V.; et al. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ˜55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. S2CID 119323941.
  5. ^ a b c d David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
  6. ^ a b Zorec, J.; Royer, F. (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. ^ "HD 220105". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 16, 2018.
  8. ^ Palous, J.; Hauck, B. (July 1986), "The Sirius supercluster", Astronomy and Astrophysics, 162: 54–61, Bibcode:1986A&A...162...54P
  9. ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920
  10. ^ Schröder, C.; Schmitt, J. H. M. M. (November 2007), "X-ray emission from A-type stars", Astronomy and Astrophysics, 475 (2): 677–684, Bibcode:2007A&A...475..677S, doi:10.1051/0004-6361:20077429.

External links edit

  • Image HD 220105