Gamma Cygni

For other uses of "Sadr", see Sadr (disambiguation).
Gamma Cygni
Location of γ Cyg (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Right ascension 20h 22m 13.70184s[1]
Declination +40° 15′ 24.0450″[1]
Apparent magnitude (V) 2.23[2]
Characteristics
Spectral type F8 Iab[3]
U−B color index +0.54[2]
B−V color index +0.67[2]
Variable type suspected[4]
Astrometry
Radial velocity (Rv)-7.5[5] km/s
Proper motion (μ) RA: +2.39[1] mas/yr
Dec.: -0.91[1] mas/yr
Parallax (π)1.78 ± 0.27 mas[1]
Distanceapprox. 1,800 ly
(approx. 560 pc)
Absolute magnitude (MV)−4.54[6]
Details
Mass14.5±1.1[7] M☉
Radius183[8] R☉
Luminosity (bolometric)33,023[9] L☉
Surface gravity (log g)1.02±0.10[7] cgs
Temperature5,790±100[7] K
Metallicity [Fe/H]+0.02[6] dex
Rotational velocity (v sin i)15[10] km/s
Age12[7] Myr
Other designations
Sadr, Sadir, Sador, 37 Cyg, HR 7796, BD+39°4159, HD 194093, SAO 49528, FK5 765, HIP 100453, WDS J20222+4015A.
Database references
SIMBADdata

Gamma Cygni (γ Cygni, abbreviated Gamma Cyg, γ Cyg), officially named Sadr /ˈsædər/,[11][12] is a star in the northern constellation of Cygnus, forming the intersection of an asterism of five stars called the Northern Cross. Based upon parallax measurements obtained during the Hipparcos mission, it is approximately 1,800 light-years (560 parsecs) from the Sun.[1]

It forms the primary or 'A' component of a multiple star system designated WDS J20222+4015 (the secondary or 'BCD' component is WDS J20222+4015BCD, a close triplet of stars 41" away from γ Cygni[13]).

  1. ^ a b c d e f Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference clpl4_99 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference aj140_5_1329 was invoked but never defined (see the help page).
  4. ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  5. ^ Cite error: The named reference rgcrv was invoked but never defined (see the help page).
  6. ^ a b Kovtyukh, V. V.; Gorlova, N. I.; Belik, S. I. (2012). "Accurate luminosities from the oxygen λ7771-4 Å triplet and the fundamental parameters of F-G supergiants". Monthly Notices of the Royal Astronomical Society. 423 (4): 3268–3273. arXiv:1204.4115. Bibcode:2012MNRAS.423.3268K. doi:10.1111/j.1365-2966.2012.21117.x. ISSN 0035-8711. S2CID 118683158.
  7. ^ a b c d Cite error: The named reference mnras402_2_1369 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference kaler was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference an331_4_349 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference coapa239_1 was invoked but never defined (see the help page).
  11. ^ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
  12. ^ "Naming Stars". IAU.org. Retrieved 1 March 2018.
  13. ^ "VizieR". vizier.cds.unistra.fr. Retrieved 2024-10-01.