Zeta1 Scorpii

ζ1 Scorpii
Location of ζ1 Scorpii (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Scorpius
Right ascension 16h 53m 59.72713s
Declination −42° 21′ 43.3073″
Apparent magnitude (V) 4.705 (4.66 to 4.86)
Characteristics
Spectral type B1.5 Ia+
U−B color index −0.567
B−V color index +0.480
Variable type Luminous blue variable
Astrometry
Radial velocity (Rv)−26.0 km/s
Proper motion (μ) RA: −0.094 mas/yr
Dec.: −3.368 mas/yr
Parallax (π)0.5855±0.1176 mas
Distanceapprox. 6,000 ly
(approx. 1,700 pc)
Absolute magnitude (MV)−8.5
Details
Mass36 to 53 M
Radius159+83
−34
 R
Luminosity (bolometric)(1.0–1.6)×106 L
Surface gravity (log g)1.7 cgs
Temperature17,000–19,000 K
Rotational velocity (v sin i)60 km/s
Age6.5±0.1 Myr
Other designations
ζ1 Sco, CD−42 11633, CPD−42 7545, GC 22730, HD 152236, HIP 82671, HR 6262, PPM 322342, SAO 227375.
Database references
SIMBADdata

Zeta1 Scorpii (Zeta1 Sco, ζ1 Scorpii, ζ1 Sco) is a binary star in the constellation of Scorpius, composed by an B-type hypergiant star as the primary, and a secondary of which little is known. It has an apparent visual magnitude which varies between 4.66 and 4.86. It is a member of the Scorpius OB1 association, and potentially of the open star cluster NGC 6231, also known as the "Northern jewel box" cluster.