Lambda Columbae
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Columba |
| Right ascension | 05h 53m 06.88101s |
| Declination | −33° 48′ 04.9079″ |
| Apparent magnitude (V) | 4.86 |
| Characteristics | |
| Spectral type | B5 V |
| U−B color index | −0.57 |
| B−V color index | −0.15 |
| Variable type | Suspected rotating ellipsoidal |
| Astrometry | |
| Radial velocity (Rv) | +30.0 km/s |
| Proper motion (μ) | RA: −4.72 mas/yr Dec.: +31.32 mas/yr |
| Parallax (π) | 9.75±0.21 mas |
| Distance | 335 ± 7 ly (103 ± 2 pc) |
| Absolute magnitude (MV) | −0.17 |
| Details | |
| Mass | 4.0±0.1 M☉ |
| Radius | 3.4 R☉ |
| Luminosity | 213 L☉ |
| Surface gravity (log g) | 4.22 cgs |
| Temperature | 13,524 K |
| Metallicity [Fe/H] | −0.06 dex |
| Rotational velocity (v sin i) | 88 km/s |
| Age | 56.6±26.1 Myr |
| Other designations | |
| λ Col, CD−33°2599, HD 39764, HIP 27810, HR 2056, SAO 196276. | |
| Database references | |
| SIMBAD | data |
Lambda Columbae, Latinized from λ Columbae, is a probable binary star in the southern constellation of Columba. With an apparent visual magnitude of 4.86, it is faintly visible to the naked eye. The measured annual parallax shift of 9.75 mas yields an estimated distance of roughly 335 light years.
Lambda Columbae has a stellar classification of B5 V, indicating that it is a B-type main sequence star. It is a suspected rotating ellipsoidal variable with a period of 0.64 days and an amplitude of 0.07 magnitude. Confirmation would indicate that this is a close binary system. It has an estimated age of around 57 million years.
In Chinese, 子 (Zǐ), meaning Son, refers to an asterism consisting of λ Columbae and β Columbae. Consequently, λ Columbae itself is known as 子一 (Zǐ yī, English: the First Star of Son.). From this Chinese name, the name Tsze is derived.