Omicron Puppis

Omicron Puppis
Location of ο Puppis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Puppis
Right ascension 07h 48m 05.16839s
Declination −25° 56 13.8123
Apparent magnitude (V) +4.48
Characteristics
Spectral type B1 IVnne
U−B color index −1.02
B−V color index −0.09
Variable type LERI
Astrometry
Radial velocity (Rv)+15.0 km/s
Proper motion (μ) RA: −10.09 mas/yr
Dec.: +4.26 mas/yr
Parallax (π)2.30±0.23 mas
Distance1,400 ± 100 ly
(430 ± 40 pc)
Absolute magnitude (MV)−3.77
Orbit
Period (P)28.903±0.004 d
Eccentricity (e)0
Periastron epoch (T)2456012.93 ± 0.04
Semi-amplitude (K2)
(secondary)
159.7±11.7 km/s
Details
Mass15.5±0.8 M
Radius13.5 R
Luminosity (bolometric)59,279 L
Surface gravity (log g)2.90 cgs
Temperature26,000 K
Rotational velocity (v sin i)315 km/s
Age11.1±0.5 Myr
Other designations
ο Pup, CPD−25°2882, HD 63462, HIP 38070, HR 3045, SAO 174558, WDS J07481-2556A
Database references
SIMBADdata

Omicron Puppis (ο Puppis) is candidate binary star system in the southern constellation of Puppis. It is visible to the naked eye, having a combined apparent visual magnitude of +4.48. Based upon an annual parallax shift of 2.30 mas as seen from Earth, it is located roughly 1,400 light years from the Sun.

This is a suspected close spectroscopic binary system. The spectrum varies with a periodicity of 28.9 days, and a helium emission component shows a radial velocity variation that matches the period. The properties indicate it may be a φ Per-like system with a Be star primary and a hot subdwarf companion of type sdO. If this is the case, then the pair have a circular orbit with a period that matches the variability. The close-orbiting pair may have undergone interaction in the past, leaving the subdwarf stripped down and the primary star spinning rapidly.

ο Puppis is slightly variable. The General Catalogue of Variable Stars lists it as a possible Be star with a magnitude range of 4.43 - 4.46. The International Variable Star Index classifies it as a Lambda Eridani variable.