Lambda Piscis Austrini

Lambda Piscis Austrini, Latinized from λ Piscis Austrini, is a solitary^[10] star in the southern constellation of Piscis Austrinus. It has a blue-white hue and is visible to the naked eye with an apparent visual magnitude of +5.42.^[2] Based upon an annual parallax shift of 6.51 mas as measured from Earth,^[1] it is located around 500 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.16 due to interstellar dust.^[5]

Lambda Piscis Austrini

Location of λ Piscis Austrini (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Piscis Austrinus
Right ascension	22h 14m 18.75029s[1]
Declination	−27° 46′ 00.8756″[1]
Apparent magnitude (V)	+5.42[2]
Characteristics
Spectral type	B7 V[3]
B−V color index	−0.12[2]
Astrometry
Radial velocity (Rv)	−6.20[4] km/s
Proper motion (μ)	RA: +23.889[1] mas/yr Dec.: +2.562[1] mas/yr
Parallax (π)	6.5148±0.2222 mas[1]
Distance	500 ± 20 ly (153 ± 5 pc)
Absolute magnitude (MV)	−0.13[5]
Details
Mass	3.58±0.08[6] M☉
Radius	4.2[7] R☉
Luminosity	249[6] L☉
Temperature	12,023[6] K
Rotational velocity (v sin i)	50[8] km/s
Age	215[5] Myr
Other designations
λ PsA, 16 Piscis Austrini, CPD−28°7566, FK5 838, HD 210934, HIP 109789, HR 8478, SAO 190985[9]
Database references
SIMBAD	data

This is a B-type main sequence star with a stellar classification of B7 V.^[3] It has an estimated 3.58^[6] times the mass of the Sun and about 4.2^[7] times the Sun's radius. The star is spinning with a projected rotational velocity of 50 km/s^[8] and is 76% of the way through its main sequence lifetime. It is radiating 249 times the solar luminosity from its photosphere at an effective temperature of 12,023 K.^[6]

Lambda Piscis Austrini is moving through the Galaxy at a speed of 18.1 km/s relative to the Sun. Its projected Galactic orbit carries it between 23,800 and 29,300 light years from the center of the Galaxy.^[11]

Naming

In Chinese, 羽林軍 (Yǔ Lín Jūn), meaning Palace Guard, refers to an asterism consisting of λ Piscis Austrini, 29 Aquarii, 35 Aquarii, 41 Aquarii, 47 Aquarii, 49 Aquarii, HD 212448, ε Piscis Austrini, 21 Piscis Austrini, 20 Piscis Austrini, υ Aquarii, 68 Aquarii, 66 Aquarii, 61 Aquarii, 53 Aquarii, 50 Aquarii, 56 Aquarii, 45 Aquarii, 58 Aquarii, 64 Aquarii, 65 Aquarii, 70 Aquarii, 74 Aquarii, τ² Aquarii, τ¹ Aquarii, δ Aquarii, 77 Aquarii, 88 Aquarii, 89 Aquarii, 86 Aquarii, 101 Aquarii, 100 Aquarii, 99 Aquarii, 98 Aquarii, 97 Aquarii, 94 Aquarii, ψ³Aquarii, ψ²Aquarii, ψ¹Aquarii, 87 Aquarii, 85 Aquarii, 83 Aquarii, χ Aquarii, ω¹ Aquarii and ω² Aquarii. Consequently, the Chinese name for λ Piscis Austrini itself is 羽林軍六 (Yǔ Lín Jūn liù, English: the Sixth Star of Palace Guard.)^[12]