Delta Geminorum

Delta Geminorum
Location of δ Geminorum (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Gemini
Right ascension 07h 20m 07.37978s
Declination +21° 58 56.3377
Apparent magnitude (V) +3.53
Characteristics
Spectral type F0 IV
U−B color index +0.04
B−V color index +0.34
Astrometry
Radial velocity (Rv)+4.1 km/s
Proper motion (μ) RA: –15.13 mas/yr
Dec.: –9.79 mas/yr
Parallax (π)53.94±0.66 mas
Distance60.5 ± 0.7 ly
(18.5 ± 0.2 pc)
Absolute magnitude (MV)1.95
Orbit
PrimaryAa
CompanionAb
Period (P)2,238.7 days
Eccentricity (e)0.3530
Orbit
PrimaryA
CompanionB
Period (P)~550 yr
Semi-major axis (a)13.8±1.6
Eccentricity (e)0.98±0.30
Inclination (i)75±10°
Longitude of the node (Ω)128±51°
Periastron epoch (T)2136±57
Argument of periastron (ω)
(secondary)
266±32°
Details
Mass1.57 M
Radius2.31 R
Luminosity9.88 L
Temperature6,900 K
Metallicity [Fe/H]–0.26 dex
Rotational velocity (v sin i)129.7 km/s
Age1.6 Gyr
Other designations
Wasat, 55 Geminorum, BD+22°1645, FK5 279, Gl 271, HD 56986, HIP 35550, HR 2777, SAO 79294.
Database references
SIMBADdata

Delta Geminorum (δ Geminorum, abbreviated Delta Gem, δ Gem), formally named Wasat /ˈwsət/, is a triple star system in the constellation of Gemini.