Gamma Cygni

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Gamma Cygni
Observation data
Equinox J2000
Constellation Cygnus
Right ascension 20h 22m 13.7s
Declination +40° 15′ 24″
Apparent magnitude (V) 2.23
Characteristics
Spectral type F8 Ib
U-B color index 0.53
B-V color index 0.673
Variable type Pulsating
Astrometry
Radial velocity (Rv) -7.5 km/s
Proper motion (μ) RA: 2.43 mas/yr
Dec.: -0.93 mas/yr
Parallax (π) 2.43 ± 0.51 mas
Distance approx. 1300 ly
(approx. 410 pc)
Absolute magnitude (MV) -6.12
Details
Mass 12 M
Radius 225 R
Luminosity 65,000 L
Temperature 6,500 K
Metallicity  ?
Rotation 20 km/s.
Age  ? years
Other designations
Sadr, Sadir, Sador, 37 Cyg, HR 7796, BD +39°4159, HD 194093, SAO 49528, FK5 765, HIP 100453.

Gamma Cygni (γ Cyg / γ Cygni) is a star in the constellation Cygnus. It also has the traditional name Sadr (also spelled Sadir or Sador).

The traditional name comes from the Arabic word صدر şadr, "chest", the same word which gave rise to the star Schedar (Alpha Cassiopeiae).

This star is surrounded by a diffuse nebula called IC1318, or the Gamma Cygni region.

[edit] External links

  • Sadr by Jim Kaler.