HD 195479

Am star in the constellation Delphinus.
HD 195479
Location of HD 195479 on the map (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Delphinus
Right ascension 20h 30m 58.26388s[1]
Declination +20° 36′ 23.0762″[1]
Apparent magnitude (V) 6.20±0.01[2]
Characteristics
Spectral type kA1 hA9 mF2[3]
U−B color index +0.13[4]
B−V color index +0.12[4]
Astrometry
Radial velocity (Rv)−40.1±1.6[5] km/s
Proper motion (μ) RA: +95.633 mas/yr[1]
Dec.: +58.78 mas/yr[1]
Parallax (π)11.3074 ± 0.0337 mas[1]
Distance288.4 ± 0.9 ly
(88.4 ± 0.3 pc)
Absolute magnitude (MV)+1.53[6]
Details
Mass2.05+0.38
−0.24[7] M☉
Radius2.15±0.11[8] R☉
Luminosity38.96+0.36
−0.42[1] L☉
Surface gravity (log g)4.08[9] cgs
Temperature8,454[10] K
Metallicity [Fe/H]−0.11[11] dex
Rotational velocity (v sin i)18.0±0.6[9] km/s
Age631[12] Myr
Other designations
AG+20°2271, BD+20°4602, GC 28540, HD 195479, HIP 101213, HR 7839, SAO 88783, CCDM J20310+2036A, WDS J20310+2036A, TIC 379435621[13]
Database references
SIMBADdata

HD 195479, also designated as HR 7839, is a solitary star located in the northern constellation Delphinus, the dolphin. It has an apparent magnitude of 6.20,[2] placing it near the limit for naked eye visibility, even under ideal conditions. The object is located relatively close at a distance of 288 light-years based on Gaia DR3 parallax measurements[1] and it is drifting closer with a heliocentric radial velocity of −40.1 km/s.[5] At its current distance, HD 195479's brightness is diminished by an interstellar extinction of 0.27 magnitudes[14] and it has an absolute magnitude of +1.53.[6]

HD 195479 is an Am star with a stellar classification of kA1hA9mF2.[3] The notion indicates that it has the calcium K-lines of an A1 star, the hydrogen lines of an A9 star, and the metallic lines of a F2 star. It has 2.05 times the mass of the Sun[7] and 2.15 times the radius of the Sun.[8] It radiates 38.96 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 8,454 K,[10] giving it white hue when viewed in the night sky. HD 195479 is deficient in iron, having an abundance 77.6% of the Sun's.[11] It is estimated to be 631 million years old[12] and it spins modestly with a projected rotational velocity of 18.0 km/s,[9] common for Am stars.

The star has two optical companions: a 12th magnitude star designated B located 5.7" away along a position angle of 88° and a 13th magnitude star designated C located 55.9" away along a position angle of 206°.[15] They were both observed by American astronomer Sherburne Wesley Burnham during the late 19th century.[16] B and C are both background stars that are far more distant than HD 195479.[17][18]

References

  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 Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (March 2002). "The Tycho double star catalogue". Astronomy & Astrophysics. 384 (1): 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822. eISSN 1432-0746. ISSN 0004-6361.
  3. ^ a b Abt, Helmut A.; Morrell, Nidia I. (July 1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". The Astrophysical Journal Supplement Series. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182. ISSN 0067-0049. S2CID 120495962.
  4. ^ a b Mendoza, E. E.; Gomez, V. T.; Gonzalez, S. (June 1978). "UBVRI photometry of 225 AM stars". The Astronomical Journal. 83: 606. Bibcode:1978AJ.....83..606M. doi:10.1086/112242. S2CID 121449759.
  5. ^ a b Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
  6. ^ a b 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.
  7. ^ a b Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. eISSN 1538-3881. hdl:1721.1/124721. S2CID 166227927.
  8. ^ a b Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (April 8, 2004). "The angular sizes of dwarf stars and subgiants: Surface brightness relations calibrated by interferometry". 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. S2CID 6077801.
  9. ^ a b c Shorlin, S. L. S.; Wade, G. A.; Donati, J.-F.; Landstreet, J. D.; Petit, P.; Sigut, T. A. A.; Strasser, S. (2002). "A highly sensitive search for magnetic fields in B, A and F stars". Astronomy & Astrophysics. 392 (2): 637–652. Bibcode:2002A&A...392..637S. doi:10.1051/0004-6361:20021192. ISSN 0004-6361. S2CID 1706867.
  10. ^ a b McDonald, I.; Zijlstra, A. A.; Watson, R. A. (15 June 2017). "Fundamental parameters and infrared excesses of Tycho–Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770–791. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433. eISSN 1365-2966. ISSN 0035-8711. S2CID 73594365.
  11. ^ a b Anders, F.; et al. (February 2022). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G = 18.5". Astronomy & Astrophysics. 658: A91. arXiv:2111.01860. Bibcode:2022A&A...658A..91A. doi:10.1051/0004-6361/202142369. eISSN 1432-0746. ISSN 0004-6361.
  12. ^ a b Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. eISSN 1562-6873. ISSN 1063-7737. S2CID 118345778.
  13. ^ "HD 195479". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved March 13, 2024.
  14. ^ Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society. 472 (4): 3805–3820. arXiv:1709.01160. Bibcode:2017MNRAS.472.3805G. doi:10.1093/mnras/stx2219. eISSN 1365-2966. ISSN 0035-8711. S2CID 118879856.
  15. ^ 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. S2CID 119533755.
  16. ^ Burnham, S. W. (November 1875). "Sixth Catalogue of 90 new double stars discovered with a 6‐inch refractor". Astronomische Nachrichten. 86 (22). Wiley: 337–350. Bibcode:1875AN.....86..337B. doi:10.1002/asna.18750862202. ISSN 0004-6337. S2CID 121918815.
  17. ^ 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.
  18. ^ 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.