Beta Piscis Austrini

Beta Piscis Austrini is a binary star^[5][6] system in the southern constellation of Piscis Austrinus that makes part of a triple star system. Its name is a Bayer designation that is Latinized from β Piscis Austrini, and abbreviated Beta PsA or β PsA. It is visible to the naked eye with an apparent visual magnitude of +4.29.^[2] Based upon an annual parallax shift of 22.84 mas as seen from the Earth,^[1] the star is located 143 light years from the Sun. These coordinates are a source of X-ray emission with a luminosity of 88.5×10²⁰ W, which is most likely coming from a source other than the A-type stars.^[11]

Beta Piscis Austrini

Location of β Piscis Austrini (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Piscis Austrinus
Right ascension	22h 31m 30.33038s[1]
Declination	−32° 20′ 45.8653″[1]
Apparent magnitude (V)	+4.29[2] (4.29 + 6.22)[3]
Characteristics
Spectral type	A1 V[4] + A2 V[5][6]
U−B color index	+0.02[2]
B−V color index	+0.01[2]
Astrometry
Radial velocity (Rv)	5.5±0.5[7] km/s
Proper motion (μ)	RA: +59.12[1] mas/yr Dec.: −18.83[1] mas/yr
Parallax (π)	22.84±0.21 mas[1]
Distance	143 ± 1 ly (43.8 ± 0.4 pc)
Absolute magnitude (MV)	1.00[8]
Details
Mass	2.33±0.07[8] M☉
Radius	2.10[9] R☉
Luminosity	37[8] L☉
Surface gravity (log g)	4.12±0.03[8] cgs
Temperature	9,638[9] K
Rotational velocity (v sin i)	30[4] km/s
Age	339[8] Myr
Other designations
β PsA, 17 Piscis Austrini, CD−32°17126, FK5 1592, HD 213398, HIP 111188, HR 8576, SAO 213883, WDS J22315-3221A[10]
Database references
SIMBAD	data

Characteristics

The magnitude 4.29^[3] primary, component A, is a white-hued A-type main sequence star with a stellar classification of A1 V.^[4] It has an estimated 2.3 times the mass of the Sun^[8] and 2.1 times the Sun's radius.^[9] The star is radiating 37 times the solar luminosity from its photosphere^[8] at an effective temperature of 9,638 K.^[9] There is evidence for an infrared excess, indicating the presence of an orbiting debris disk. This has an estimated temperature of 188 K, indicating an orbital distance of 12 AU from the host star.^[9] The magnitude 6.22^[3] secondary, component B, has a class of A2 V and lies at an angular separation of 30.3 arc seconds.^[5][6]

The third component is the proper motion companion^[12] CD-32°17127, of apparent magnitude 7.04.^[13] It is a G-type main-sequence star of spectral class G1V, with 1.04 times the mass of the Sun,^[12] 1.03 times the Sun's radius, a luminosity 1.22 times solar and an effective temperature of 6,000 K.^[14] This star is separated from β Piscis Austrini by 1,376 astronomical units.^[12]

Beta Piscis Austrini is moving through the Galaxy at a speed of 14.4 km/s relative to the Sun. Its projected Galactic orbit carries it between 23,901 and 28,366 light-years from the center of the Galaxy.^[15]

With Delta and Zeta it constituted Tien Kang ("heavenly rope") in China.^[16][17]