HR 4138
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Carina |
| Right ascension | 10h 30m 20.12710s |
| Declination | −71° 59′ 34.0602″ |
| Apparent magnitude (V) | +4.72 |
| Characteristics | |
| Spectral type | A2IV or A1V or A2III |
| B−V color index | +0.042±0.007 |
| Astrometry | |
| Radial velocity (Rv) | +7.5±0.4 km/s |
| Proper motion (μ) | RA: +27.59 mas/yr Dec.: −30.73 mas/yr |
| Parallax (π) | 12.52±0.17 mas |
| Distance | 261 ± 4 ly (80 ± 1 pc) |
| Absolute magnitude (MV) | 0.21 |
| Details | |
| Mass | 2.10 M☉ |
| Radius | 3.45 R☉ |
| Luminosity | 75.06 L☉ |
| Surface gravity (log g) | 3.71 cgs |
| Temperature | 9,169±312 K |
| Metallicity [Fe/H] | +0.06 dex |
| Rotational velocity (v sin i) | 12 km/s |
| Age | 403 Myr |
| Other designations | |
| K Car, CD−71°1034, FK5 2842, GC 14457, HD 91375, HIP 51438, HR 4138, SAO 256722 | |
| Database references | |
| SIMBAD | data |
HR 4138 is a single star in the constellation Carina. It has the Bayer designation K Carinae, abbreviated K Car, while HR 4138 is the star's designation in the Bright Star Catalogue. It has a white hue and is faintly visible to the naked eye with an apparent visual magnitude of +4.72. This star is located at a distance of approximately 261 light years from the Sun based on parallax measurements, and it is drifting further away with a radial velocity of +7.5 km/s. Judging from its motion through space, it is a candidate member of the Sirius supercluster.
This object is a superficially normal A-type star. However, there is some disagreement over the evolutionary state of the star, as it has received luminosity classifications of a subgiant, main sequence, and a giant star. Unexpectedly for an A-type star, a magnetic field has been detected. It is around 400 million years old and has a low projected rotational velocity of 12 km/s. The star displays an infrared excess, indicating the presence of an orbiting debris disk with a black body temperature of 45 K at a separation of 314.2 AU from the host star.