Delta Pyxidis

Delta Pyxidis (δ Pyxidis) is binary star^[9] system in southern constellation of Pyxis. Having an apparent visual magnitude of +4.877,^[2] it is bright enough to be visible to the naked eye. Based upon an annual parallax shift of 13.19 mas as seen from Earth,^[1] it is located around 250 light years from the Sun.

Delta Pyxidis

Location of δ Pyxidis (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Pyxis
Right ascension	08h 55m 31.56948s[1]
Declination	−27° 40′ 54.7315″[1]
Apparent magnitude (V)	+4.877[2]
Characteristics
Spectral type	A3 IV[3]
U−B color index	+0.224[2]
B−V color index	+0.130[2]
Astrometry
Radial velocity (Rv)	5.4±0.8[4] km/s
Proper motion (μ)	RA: +81.90[1] mas/yr Dec.: −100.43[1] mas/yr
Parallax (π)	13.19±0.77 mas[1]
Distance	250 ± 10 ly (76 ± 4 pc)
Absolute magnitude (MV)	+0.67[5]
Details
Mass	1.84[6] M☉
Radius	1.6[7] R☉
Luminosity	59[3] L☉
Surface gravity (log g)	3.77±0.14[6] cgs
Temperature	8,609±293[6] K
Rotational velocity (v sin i)	68[6] km/s
Age	296[6] Myr
Other designations
δ Pyx, CPD−27° 3497, HD 76483, HIP 43825, HR 3556, SAO 176697, WDS J08555-2741A[8]
Database references
SIMBAD	data

In Chinese, 天狗 (Tiān Gǒu), meaning Celestial Dog, refers to an asterism consisting of δ Pyxidis, e Velorum, f Velorum, β Pyxidis, α Pyxidis and γ Pyxidis. Consequently, δ Pyxidis itself is known as 天狗七 (Tiān Gǒu qī, English: the Seventh Star of Celestial Dog.)^[10]

This is an astrometric binary system, as determined by changes in the proper motion of the primary.^[11] The visible component has a stellar classification of A3 IV,^[3] indicating it has the spectrum of an A-type subgiant star that is consuming the last of the hydrogen at its core. At the age of around 296 million years,^[6] it is 92.5%^[3] of the way through its main sequence lifetime and is spinning with a projected rotational velocity of 68 km/s.^[6] The star has an estimated 1.8^[6] times the mass of the Sun and about 1.6^[7] times the Sun's radius. It is radiating 59^[3] times the Sun's luminosity from its photosphere at an effective temperature of roughly 8,609 K.^[6]