HD 110432

HD 110432
Location of BZ Crucis (circled). The other star shown overlapping/underlying the dark nebula is HD 109000 (HR 4771) which is a red/brown star about half the distance to the nebula, having parallax of 12.8 ± 0.05 thus about 250 light years away
Observation data
Epoch J2000      Equinox J2000
Constellation Crux
Right ascension 12h 42m 50.2656s
Declination −63° 03 31.048
Apparent magnitude (V) 5.24 - 5.45
Characteristics
Spectral type B1IVe
U−B color index −0.82
B−V color index +0.27
Variable type γ Cas
Astrometry
Radial velocity (Rv)+35 km/s
Proper motion (μ) RA: −12.512 mas/yr
Dec.: −3.984 mas/yr
Parallax (π)2.3834±0.1228 mas
Distance1,370 ± 70 ly
(420 ± 20 pc)
Absolute magnitude (MV)−2.56
Details
Mass9.6 M
Radius6.5±1.2 R
Luminosity1,153 L
Surface gravity (log g)3.5–3.9 cgs
Temperature22,510–25,000 K
Rotational velocity (v sin i)300–400 km/s
Other designations
BZ Cru, HR 4830, CD-62 671, HD 110432, GCTP, SAO 252002, FK5 3015, HIP 62027.
Database references
SIMBADdata

HD 110432 is a Be star in the south-east of Crux, behind the center of the southern hemisphere's dark Coalsack Nebula. It has a stellar classification of B1IVe, which means it is a subgiant star of class B that displays emission lines in its spectrum. This is a variable star of the Gamma Cassiopeiae type, indicating it is a shell star with a circumstellar disk of gas about the equator, and has the variable star designation BZ Crucis. It is not known to be a member of a binary system, although it is probably a member of the open cluster NGC 4609. This star is moderately luminous in the X-ray band, with a variable energy emission of 103233 erg s−1 in the range 0.2−12 keV. The X-ray emission may be caused by magnetic activity, or possibly by accretion onto a white dwarf companion.