HD 102776
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 11h 49m 41.05745s |
| Declination | −63° 47′ 18.4299″ |
| Apparent magnitude (V) | 4.30 (+4.30 - 4.39) |
| Characteristics | |
| Spectral type | B3V |
| U−B color index | −0.59 |
| B−V color index | −0.15 |
| Variable type | γ Cas |
| Astrometry | |
| Radial velocity (Rv) | +29.0±4.1 km/s |
| Proper motion (μ) | RA: -20.76 ± 0.56 mas/yr Dec.: 4.30 ± 0.48 mas/yr |
| Parallax (π) | 5.4391±0.4369 mas |
| Distance | 600 ± 50 ly (180 ± 10 pc) |
| Absolute magnitude (MV) | −1.98 |
| Details | |
| Mass | 5.955 M☉ 7.2±0.1 M☉ |
| Radius | 5.00±0.10 R☉ |
| Luminosity | 1,342 L☉ |
| Surface gravity (log g) | 3.20±0.03 cgs |
| Temperature | 20,000±200 K |
| Rotational velocity (v sin i) | 200±4 km/s |
| Age | 31.6±0.6 Myr |
| Other designations | |
| j Cen, NSV 5357, CPD−63°1988, FK5 2944, GC 16201, HD 102776, HIP 57669, HR 4537, SAO 251602 | |
| Database references | |
| SIMBAD | data |
HD 102776, also known by its Bayer designation j Centauri, is a suspected astrometric binary star system in the southern constellation of Centaurus. It has a blue-white hue and is faintly visible to the naked eye with a typical apparent visual magnitude of 4.30. The distance to this star is approximately 600 light years based on parallax, and it is drifting further away with a radial velocity of ~29 km/s. It is a member of the Lower Centaurus Crux subgroup of the Sco OB2 association. HD 102776 has a relatively large peculiar velocity of 31.1 km/s and is a candidate runaway star that was ejected from its association, most likely by a supernova explosion.
The stellar classification of the visible component is B3V, matching a B-type main-sequence star. It is around 32 million years old and is spinning rapidly with estimates of its projected rotational velocity ranging from 200 up to 270 km/s, giving it an equatorial bulge that is up to 11% larger than the polar radius. This is a Be star showing emission features in its Balmer lines due to a circumstellar disk of decreated gas. It is classified as a suspected Gamma Cassiopeiae type variable star with a visual magnitude varying from +4.30 down to +4.39.