HD 96919
Variable star in the constellation Carina
From Wikipedia, the free encyclopedia
HD 96919, also known by its Bayer designation of z2 Carinae and the variable star designation of V371 Carinae, is a blue supergiant star in the constellation Carina. It lies near the Carina Nebula and at a comparable distance. A 5th magnitude star, it is visible to the naked eye under good observing conditions.
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Carina |
| Right ascension | 11h 08m 33.99848s[1] |
| Declination | −61° 56′ 49.8316″[1] |
| Apparent magnitude (V) | 5.19[2] (5.12 - 5.19[3]) |
| Characteristics | |
| Spectral type | B9 Iae[4] |
| U−B color index | −0.46[2] |
| B−V color index | +0.23[2] |
| Variable type | α Cyg[3] |
| Astrometry | |
| Radial velocity (Rv) | −22.4 ± 2[5] km/s |
| Proper motion (μ) | RA: −5.78[1] mas/yr Dec.: 1.74[1] mas/yr |
| Parallax (π) | 0.23±0.25 mas[1] |
| Distance | 1,920[6] pc |
| Absolute magnitude (MV) | −7.0[6] |
| Details | |
| Mass | 23[4] M☉ |
| Radius | 141[4] R☉ |
| Luminosity | 105,000[7] L☉ |
| Surface gravity (log g) | 1.50[4] cgs |
| Temperature | 12,500[7] K |
| Rotational velocity (v sin i) | 60[4] km/s |
| Other designations | |
| z2 Carinae, V371 Carinae, 261 G. Carinae,[8] CD−61°2941, CPD−61°2075, CPC 20.1 3080, FK5 2891, GC 15331, GCRV 6856, GSC 08962-02640, HD 96919, HIC 54461, HIP 54461, HR 4338, PPM 358516, SAO 251286 | |
| Database references | |
| SIMBAD | data |
In 1977, Christiaan Sterken announced his discovery that HD 96919 is a variable star.[10] It was given its variable star designation in 1979.[11] V371 Car is an α Cyg variable, erratically pulsating and changing brightness by a few hundredths of a magnitude. Periods of 10–80 days have been identified.[7] It shows unusual emission lines in its spectrum, and high-velocity absorption (HVA) events, temporary spectral features that are thought to indicate localised regions of enhanced mass loss.[12]
HD 96919 is a B9 supergiant, possibly located 6,000 light-years from Earth. It is considered to be a post-red supergiant star, either evolving towards a Wolf–Rayet star or on a blue loop before returning to a cooler temperature.[7]