Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Libra |
Right ascension | 15h 38m 39.36950s [1] |
Declination | −29° 46′ 39.8956″ [1] |
Apparent magnitude (V) | 3.68 [2] |
Characteristics | |
Spectral type | B2.5 V [3] |
U−B color index | −0.717 [2] |
B−V color index | −0.179 [2] |
Astrometry | |
Radial velocity (Rv) | +33.3±2.3 [4] km/s |
Proper motion (μ) |
RA: −22.08
[1]
mas/
yr Dec.: −24.46 [1] mas/ yr |
Parallax (π) | 8.89 ± 0.20 mas [1] |
Distance | 367 ± 8
ly (112 ± 3 pc) |
Absolute magnitude (MV) | −1.59 [5] |
Orbit [6] | |
Period (P) | 3.2907 d |
Eccentricity (e) | 0.28 |
Longitude of the node (Ω) | 114° |
Periastron epoch (T) | 2439272.312 JD |
Semi-amplitude (K1) (primary) | 75 km/s |
Semi-amplitude (K2) (secondary) | 167 km/s |
Details | |
τ Lib A | |
Mass | 7.25±0.49 [7] M☉ |
Radius | 3.2 [8] R☉ |
Luminosity (bolometric) | 2,705 [7] L☉ |
Surface gravity (log g) | 4.33 [9] cgs |
Temperature | 17,990 [9] K |
Metallicity [Fe/H] | +0.17 [9] dex |
Rotational velocity (v sin i) | 134 [4] km/s |
Age | 31.5±5.6 [10] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Tau Librae, Latinized from τ Librae, is the Bayer designation for a binary star system at the southern edge of the zodiac constellation of Libra. It can be seen with the naked eye, having an apparent visual magnitude of 3.68. [2] The distance to this system is around 367 light years, as determined from an annual parallax shift of 8.89 mas. [1]
Judging by its motion through space and physical properties, this system is a member of the Upper Centaurus–Lupus group of the Scorpius–Centaurus association. [4] It is double-lined [12] spectroscopic binary with an orbital period of just 3.3 days and an eccentricity of 0.28. [6] The primary, component A, is a B-type main sequence star with a stellar classification of B2.5 V. [3] It is estimated to hold more than seven [7] times the mass of the Sun and have over three [8] times the Sun's radius. It is only 31.5 [10] million years old and is spinning relatively rapidly with a projected rotational velocity of 134 km/s. [4] It is a heartbeat star system, with pulsations caused by tidal forces. [13]
The system is emitting an infrared excess, suggesting the presence of a circumstellar disk of material. [9]
{{
cite web}}
: CS1 maint: postscript (
link)
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Libra |
Right ascension | 15h 38m 39.36950s [1] |
Declination | −29° 46′ 39.8956″ [1] |
Apparent magnitude (V) | 3.68 [2] |
Characteristics | |
Spectral type | B2.5 V [3] |
U−B color index | −0.717 [2] |
B−V color index | −0.179 [2] |
Astrometry | |
Radial velocity (Rv) | +33.3±2.3 [4] km/s |
Proper motion (μ) |
RA: −22.08
[1]
mas/
yr Dec.: −24.46 [1] mas/ yr |
Parallax (π) | 8.89 ± 0.20 mas [1] |
Distance | 367 ± 8
ly (112 ± 3 pc) |
Absolute magnitude (MV) | −1.59 [5] |
Orbit [6] | |
Period (P) | 3.2907 d |
Eccentricity (e) | 0.28 |
Longitude of the node (Ω) | 114° |
Periastron epoch (T) | 2439272.312 JD |
Semi-amplitude (K1) (primary) | 75 km/s |
Semi-amplitude (K2) (secondary) | 167 km/s |
Details | |
τ Lib A | |
Mass | 7.25±0.49 [7] M☉ |
Radius | 3.2 [8] R☉ |
Luminosity (bolometric) | 2,705 [7] L☉ |
Surface gravity (log g) | 4.33 [9] cgs |
Temperature | 17,990 [9] K |
Metallicity [Fe/H] | +0.17 [9] dex |
Rotational velocity (v sin i) | 134 [4] km/s |
Age | 31.5±5.6 [10] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Tau Librae, Latinized from τ Librae, is the Bayer designation for a binary star system at the southern edge of the zodiac constellation of Libra. It can be seen with the naked eye, having an apparent visual magnitude of 3.68. [2] The distance to this system is around 367 light years, as determined from an annual parallax shift of 8.89 mas. [1]
Judging by its motion through space and physical properties, this system is a member of the Upper Centaurus–Lupus group of the Scorpius–Centaurus association. [4] It is double-lined [12] spectroscopic binary with an orbital period of just 3.3 days and an eccentricity of 0.28. [6] The primary, component A, is a B-type main sequence star with a stellar classification of B2.5 V. [3] It is estimated to hold more than seven [7] times the mass of the Sun and have over three [8] times the Sun's radius. It is only 31.5 [10] million years old and is spinning relatively rapidly with a projected rotational velocity of 134 km/s. [4] It is a heartbeat star system, with pulsations caused by tidal forces. [13]
The system is emitting an infrared excess, suggesting the presence of a circumstellar disk of material. [9]
{{
cite web}}
: CS1 maint: postscript (
link)