V518 Carinae
Blue-hued variable star in the constellation Carina
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V518 Carinae (HR 4196) is a naked eye variable star in the constellation Carina. It is a member of the bright open cluster IC 2602 near the Carina Nebula.
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| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Carina |
| Right ascension | 10h 42m 14.12927s[1] |
| Declination | −64° 27′ 59.1340″[1] |
| Apparent magnitude (V) | 4.63 - 4.82[2] |
| Characteristics | |
| Evolutionary stage | main sequence[1] |
| Spectral type | B3/5V[3] |
| U−B color index | −0.58[4] |
| B−V color index | −0.14[4] |
| Variable type | γ Cas?[5] |
| Astrometry | |
| Proper motion (μ) | RA: −17.821[1] mas/yr Dec.: +11.580[1] mas/yr |
| Parallax (π) | 6.7516±0.0843 mas[1] |
| Distance | 483 ± 6 ly (148 ± 2 pc) |
| Absolute magnitude (MV) | −1.169[6] |
| Details | |
| Mass | 6.2[7] M☉ |
| Radius | 3.30±0.07[8] R☉ |
| Luminosity | 753[6] L☉ |
| Surface gravity (log g) | 4.015[9] cgs |
| Temperature | 15,397[6] K |
| Rotational velocity (v sin i) | 120[9] km/s |
| Age | 17.2[10] Myr |
| Other designations | |
| V518 Carinae, HD 92938, HIP 52370, HR 4196 | |
| Database references | |
| SIMBAD | data |
Location
V518 Carinae lies in the open cluster IC 2602, 5 arc minutes from its brightest member θ Carinae.
Variability
V518 Carinae was discovered to change in brightness after analysis of Hipparcos photometry.[12] The amplitude of the variations seen is 0.2 magnitudes, with possible periods of 100 and 971 days.[13] It is classified as a γ Cassiopeiae variable.[14][5]
Spectral peculiarities
V518 Carinae is classified as a B-type main sequence star between B3 and B5.[15] It is also catalogued as a helium star, a chemically peculiar star with abnormally strong helium absorption lines in its spectrum and relatively weak hydrogen lines. It is possibly a blue straggler.[16]
V518 Carinae is also a Be star, a hot star with emission lines in its spectrum due to a disk of material around the star. Be stars that show irregular brightness changes due to the disk are grouped as γ Cassiopeiae variables. V518 Carinae is known to produce disk outbursts lasting several hundred days.[17]