HD 220105

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,[2] and can be a challenge to spot under normal viewing conditions. The star is located 239 light years away, based upon an annual parallax shift of 13.63 mas.[1] It is moving closer to the Earth with a heliocentric radial velocity of −2 km/s.[4]

HD 220105
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension  23h 20m 44.09815s[1]
Declination +44° 06′ 58.1991″[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: −9.368[1] mas/yr
Dec.: −36.972[1] mas/yr
Parallax (π)13.6314 ± 0.0382[1] mas
Distance239.3 ± 0.7 ly
(73.4 ± 0.2 pc)
Details[5]
Mass1.85 M☉
Luminosity18.4+1.9
−3.7[6] L☉
Surface gravity (log g)4.19±0.14 cgs
Temperature8,367±284 K
Rotational velocity (v sin i)259[6] km/s
Age525 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,[3] where the 'n' notation indicates "nebulous" absorption lines due to rapid rotation. It is around 525[5] million years old with a high projected rotational velocity of 259 km/s.[6] The star has 1.85[5] times the mass of the Sun and is radiating 18[6] times the Sun's luminosity from its photosphere at an effective temperature of 8,367 K.[5]

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
  1. 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.
  2. 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.
  5. 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.
  6. 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.
  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, 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.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.