Pi Scorpii
Triple star system in the constellation of Scorpius / From Wikipedia, the free encyclopedia
Pi Scorpii or π Scorpii, is a triple star[10] system in the southern constellation of Scorpius. With a combined apparent magnitude of 2.9,[2] it can be easily seen with the naked eye. Parallax measurements yield an estimated distance of around 590 light-years (180 parsecs) from the Sun.[2]
Quick Facts Observation data Epoch J2000 Equinox J2000, Constellation ...
Observation data Epoch J2000 Equinox J2000 | |
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Constellation | Scorpius |
Right ascension | 15h 58m 51.11324s[1] |
Declination | −26° 06′ 50.7886″[1] |
Apparent magnitude (V) | 2.890[2] |
Characteristics | |
Spectral type | B1 V + B2 V[3] |
U−B color index | −0.918[2] |
B−V color index | −0.187[2] |
Variable type | Eclipsing binary |
Astrometry | |
Radial velocity (Rv) | −3[4] km/s |
Proper motion (μ) | RA: −11.42[1] mas/yr Dec.: −26.83[1] mas/yr |
Parallax (π) | 5.57 ± 0.64 mas[1] |
Distance | approx. 590 ly (approx. 180 pc) |
Absolute magnitude (MV) | −3.35[5] |
Orbit[6] | |
Period (P) | 1.570103±0.000005 d[7] |
Semi-major axis (a) | ~0.07 AU |
Eccentricity (e) | 0.0 |
Inclination (i) | ~42° |
Semi-amplitude (K1) (primary) | 124.1±1.5 km/s |
Semi-amplitude (K2) (secondary) | 196.1±1.8 km/s |
Details | |
π Sco A | |
Mass | 12.5±0.6[8] M☉ |
Radius | 5[6] R☉ |
Luminosity | 21,900[9] L☉ |
Temperature | 25,230[9] K |
Rotation | 100[9] |
Rotational velocity (v sin i) | 108[6] km/s |
Age | 15.4±0.6[8] 12–14[9] Myr |
π Sco B | |
Mass | 9 M☉ |
Radius | 4[6] R☉ |
Luminosity | 3000 L☉ |
Temperature | 21000 K |
Rotational velocity (v sin i) | 87[6] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Close
It consists of a binary pair, designated Pi Scorpii A, with a more distant third companion, B. A's two components are themselves designated Pi Scorpii Aa (formally named Fang)[11] and Ab.