WZ Columbae

A light curve for WZ Columbae, plotted from TESS data[1]
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

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]

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]

References