Upsilon Scorpii

υ Scorpii
Location of υ Scorpii (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Scorpius
Right ascension 17h 30m 45.83712s
Declination −37° 17 44.9285
Apparent magnitude (V) 2.70
Characteristics
Spectral type B2 IV
U−B color index −0.854
B−V color index −0.221
Astrometry
Radial velocity (Rv)+8.0 km/s
Proper motion (μ) RA: −2.37 mas/yr
Dec.: +30.09 mas/yr
Parallax (π)5.66±0.18 mas
Distance580 ± 20 ly
(177 ± 6 pc)
Absolute magnitude (MV)−3.53
Details
Mass11.4±0.5 M
Radius6.1 R
Luminosity7,381 L
Temperature22,831±169 K
Age20.0±2.6 Myr
Other designations
Lesath, υ Sco, 34 Sco, 34 Scorpii, CD−37°11638, HD 158408, HIP 85696, HR 6508, SAO 208896
Database references
SIMBADdata

Upsilon Scorpii (υ Scorpii, abbreviated Upsilon Sco, υ Sco), formally named Lesath /ˈlsæθ/, is a star located in the "stinger" of the southern zodiac constellation of Scorpius, the scorpion. Based on parallax measurements obtained during the Hipparcos mission, it is approximately 580 light-years from the Sun. In the night sky it lies near the 1.6 magnitude star Lambda Scorpii, and the two form an optical pair that is sometimes called the "Cat's Eyes".