Lambda Piscis Austrini
Star in the constellation Piscis Austrinus
From Wikipedia, the free encyclopedia
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.[6]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Piscis Austrinus |
| Right ascension | 22h 14m 18.75029s[1] |
| Declination | â27° 46â² 00.8756â³[1] |
| Apparent magnitude (V) | +5.42[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | B7 V[4] |
| BâV color index | â0.12[2] |
| Astrometry | |
| Radial velocity (Rv) | â6.20[5] km/s |
| Proper motion (μ) | RA: +23.889[1] mas/yr Dec.: +2.562[1] mas/yr |
| Parallax (Ï) | 6.5148±0.2222 mas[1] |
| Distance | 500 ± 20 ly (153 ± 5 pc) |
| Absolute magnitude (MV) | â0.13[6] |
| Details | |
| Mass | 3.58±0.08[3] Mâ |
| Radius | 4.2[7] Râ |
| Luminosity | 249[3] Lâ |
| Temperature | 12,023[3] K |
| Rotational velocity (v sin i) | 50[8] km/s |
| Age | 215[6] Myr |
| Other designations | |
| λ PsA, 16 Piscis Austrini, CPDâ28°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.[4] It has an estimated 3.58[3] 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.[3]
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, ç¾½æè» (YÇ LÃn JÅ«n), 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, Ï 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, Ï2 Aquarii, Ï1 Aquarii, δ Aquarii, 77 Aquarii, 88 Aquarii, 89 Aquarii, 86 Aquarii, 101 Aquarii, 100 Aquarii, 99 Aquarii, 98 Aquarii, 97 Aquarii, 94 Aquarii, Ï3Aquarii, Ï2Aquarii, Ï1Aquarii, 87 Aquarii, 85 Aquarii, 83 Aquarii, Ï Aquarii, Ï1 Aquarii and Ï2 Aquarii. Consequently, the Chinese name for λ Piscis Austrini itself is ç¾½æè»å (YÇ LÃn JÅ«n liù, English: the Sixth Star of Palace Guard.)[12]