Theta Columbae
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Columba |
| Right ascension | 06h 07m 31.63216s |
| Declination | −37° 15′ 10.5114″ |
| Apparent magnitude (V) | 5.02 |
| Characteristics | |
| Spectral type | B8 IV |
| B−V color index | −0.11 |
| Astrometry | |
| Radial velocity (Rv) | +45.3±1.8 km/s |
| Proper motion (μ) | RA: +0.12 mas/yr Dec.: +0.41 mas/yr |
| Parallax (π) | 4.52±0.16 mas |
| Distance | 720 ± 30 ly (221 ± 8 pc) |
| Absolute magnitude (MV) | −1.72 |
| Details | |
| Mass | 4.13±0.09 M☉ |
| Luminosity | 472 L☉ |
| Temperature | 9,916 K |
| Rotational velocity (v sin i) | 249 km/s |
| Age | 237 Myr |
| Other designations | |
| Elkurud, θ Col, CD−37°2609, FK5 2468, HD 42167, HIP 29034, HR 2177, SAO 196514 | |
| Database references | |
| SIMBAD | data |
Theta Columbae, also named Elkurud /ˈɛlkərʌd/, is a solitary star in the southern constellation of Columba. It is faintly visible to the naked eye, having an apparent visual magnitude of 5.02. Based upon parallax measurements taken during the Hipparcos mission, it is roughly 720 light-years (220 parsecs) distant from the Sun. At its present distance, the visual magnitude of the star is reduced by an interstellar extinction factor of 0.11. It is currently moving away from the Sun with a radial velocity of 45.3 km/s. The star made its closest approach about 4.7 million years ago when it underwent perihelion passage at a distance of 10.9 ly (3.33 pc).
This is an evolving B-type subgiant star with a stellar classification of B8 IV, having recently left the main sequence. It is spinning rapidly with a projected rotational velocity of 249 km/s. The star has an estimated four times the mass of the Sun. It radiates 472 times the solar luminosity from its outer atmosphere at an effective temperature of 9,916 K.