Alpha Pyxidis

Alpha Pyxidis, Latinised from α Pyxidis, is a giant star in the constellation Pyxis. It is the brightest star in Pyxis, and is easily visible to the naked eye. It has a stellar classification of B1.5III and is a Beta Cephei variable. This star has more than ten times the mass of the Sun and is more than six times the Sun's radius. The surface temperature is 24,300 K and the star is about 10,000 times as luminous as the Sun.^[3][4][8] Stars such as this with more than 10 solar masses are expected to end their life by exploding as a supernova.^[11]

A light curve for Alpha Pyxidis, plotted from TESS data.^[12]

Alpha Pyxidis

Location of α Pyxidis (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Pyxis
Right ascension	08h 43m 35.53756s[1]
Declination	−33° 11′ 10.9898″[1]
Apparent magnitude (V)	3.67[2]
Characteristics
Spectral type	B1.5III[3]
U−B color index	−0.84[2]
B−V color index	−0.19[2]
Variable type	Beta Cephei[4]
Astrometry
Radial velocity (Rv)	+15.3[5] km/s
Proper motion (μ)	RA: −14.27[1] mas/yr Dec.: +10.43[1] mas/yr
Parallax (π)	3.71±0.14 mas[1]
Distance	880 ± 30 ly (270 ± 10 pc)
Absolute magnitude (MV)	−3.47[6]
Details
Mass	10.7[4] M☉
Radius	6.3 ± 1.0[7] R☉
Luminosity	10,000[4] L☉
Surface gravity (log g)	3.63[8] cgs
Temperature	24,300[8] K
Metallicity [Fe/H]	−0.18[8] dex
Rotational velocity (v sin i)	11[9] km/s
Other designations
Alpha Pyx, α Pyx, CPD−32° 2399, FK5 327, HD 74575, HIP 42828, HR 3468, SAO 199546[10]
Database references
SIMBAD	data

Naming

In Chinese, 天狗 (Tiān Gǒu), meaning Celestial Dog, refers to an asterism consisting of α Pyxidis, e Velorum, f Velorum, β Pyxidis, γ Pyxidis and δ Pyxidis. Consequently, α Pyxidis itself is known as 天狗五 (Tiān Gǒu wǔ, English: the Fifth Star of Celestial Dog).^[13]