WZ Columbae
Star in the constellation of Columba
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WZ Columbae, also known as HD 38170, is a solitary,[19] bluish-white hued star located in the southern constellation Columba, the dove. It has an apparent magnitude of 5.28,[3] allowing it to be faintly visible to the naked eye. Based on parallax measurements from the Gaia spacecraft, the object is about 365 light years distant.[2] It appears to be receding from the Solar System, having a heliocentric radial velocity of 36.3 km/s.[9]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Columba |
| Right ascension | 05h 42m 15.19447s[2] |
| Declination | −34° 40′ 04.1399″[2] |
| Apparent magnitude (V) | 5.28±0.01[3] |
| Characteristics | |
| Evolutionary stage | main sequence[4] |
| Spectral type | B9/9.5 V[5] |
| B−V color index | −0.05[6] |
| Variable type | SPB[7] or α2 CVn[8] |
| Astrometry | |
| Radial velocity (Rv) | 36.3±0.6[9] km/s |
| Proper motion (μ) | RA: +5.081 mas/yr[2] Dec.: +51.365 mas/yr[2] |
| Parallax (π) | 8.929±0.08896 mas[2] |
| Distance | 365 ± 4 ly (112 ± 1 pc) |
| Absolute magnitude (MV) | −0.3[10] |
| Details | |
| Mass | 3.07±0.05[4] M☉ |
| Radius | 3.47[11] R☉ |
| Luminosity | 124[12] L☉ |
| Surface gravity (log g) | 3.79±0.07[13] cgs |
| Temperature | 10,000+256 −250[4] K |
| Metallicity [Fe/H] | +0.51[14] dex |
| Rotational velocity (v sin i) | 65±5[15] km/s |
| Age | 394+10 −17[16] Myr |
| Other designations | |
| 42 G. Columbae[17], WZ Col, CD−34°2401, CPD−34°711, GC 7150, HD 38170, HIP 26868, HR 1973, SAO 196098[18] | |
| Database references | |
| SIMBAD | data |
The star was discovered to be a variable star when the Hipparcos data was analyzed. It was given its variable star designation in 1999.[20] WZ Columbae was originally listed as a slowly pulsating B-type star by the General Catalogue of Variable Stars. However, observations from Hempel & Howlger (2003) reveal it to be overabundant in strontium and barium.[14] Combined with Hipparcos photometry, this led to the object being reclassified as an Alpha2 Canum Venaticorum variable.[8] Based on data collected in the Hipparcos passband, it fluctuates between magnitudes 5.27 and 5.29 over 1.38 days.[7][21] However, TESS data suggests a period of 2.76618±0.00004 days; double that of the earlier data.[16]
The stellar classification of WZ Columbae is B9/9.5 V[5] — a main-sequence star with the characteristics of a B9 and B9.5 star. It has 3.07[4] times the mass of the Sun and is estimated to be 394 million years old,[16] having completed 89.2% of its main sequence lifetime.[4] It has a slightly enlarged radius of 3.47 R☉[11] and an effective temperature of 10,000 K.[4] This yields a luminosity 124 times that of the Sun[12] from its photosphere. Like most chemically peculiar stars, WZ Columbae has a relatively slow projected rotational velocity at 65 km/s.[15]