Theta Scorpii

Theta Scorpii
Location of θ Scorpii (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Scorpius
Right ascension 17h 37m 19.12985s
Declination −42° 59′ 52.1808″
Apparent magnitude (V) 1.84 (1.862 + 6.22)
Characteristics
Evolutionary stage Post-stellar merger
Spectral type F1III
U−B color index +0.21
B−V color index +0.40
Astrometry
Radial velocity (Rv)+1.4 km/s
Proper motion (μ) RA: +5.54 mas/yr
Dec.: −3.12 mas/yr
Parallax (π)9.90±0.26 mas
Distance329 ± 9 ly
(101 ± 3 pc)
Absolute magnitude (MV)−2.71
Details
Mass3.10+0.37
−0.32
 M
Radius35.5 (equatorial)
26.3 (polar) R
Luminosity1,400 L
Surface gravity (log g)2.4±0.2 cgs
Temperature6,294 K
Rotation16.60 days
Rotational velocity (v sin i)125 km/s
Other designations
Sargas, Girtab, 160 G. Scorpii, θ Sco, CD−42°12312, FK5 654, HD 159532, HIP 86228, HR 6553, SAO 228201, CCDM J17373−4300
Database references
SIMBADdata

Theta Scorpii (θ Scorpii, abbreviated Theta Sco, θ Sco) is a binary star in the southern zodiac constellation of Scorpius. The apparent visual magnitude of this star is +1.87, making it readily visible to the naked eye and one of the brightest stars in the night sky. It is sufficiently near that the distance can be measured directly using the parallax technique and such measurements obtained during the Hipparcos mission yield an estimate of approximately 329 light-years (101 parsecs) from the Sun.

The two components are designated θ Scorpii A (officially named Sargas /ˈsɑːrɡæs/, the traditional name for the system) and B.