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
τ Lib, 40 Lib, CD−29° 11837, HD 139365, HIP 76600, HR 5812, SAO 183649.[11]
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]
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^ abCite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
^Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
^Cite error: The named reference Strom2005 was invoked but never defined (see the help page).
^Sharma, Awshesh N.; Bedding, Timothy R.; Saio, Hideyuki; White, Timothy R. (2022). "Pulsating B stars in the Scorpius–Centaurus Association with TESS". Monthly Notices of the Royal Astronomical Society. 515 (1): 828–840. arXiv:2203.02582. Bibcode:2022MNRAS.515..828S. doi:10.1093/mnras/stac1816.
TauLibrae, 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...
Gliese 570 (or 33 G. Librae) is a quaternary star system approximately 19 light-years away. The primary star is an orange dwarf star (much dimmer and smaller...
rich cultural heritage". Vancouver Sun. p. G2. "รายงานผลการวิจัย" (PDF). librae.mju.ac.th (in Thai). "[Thaifoodmaster] Tutorial – How to Make Fermented...
with δ Librae, were the first stars on which rotational line broadening was observed, by Frank Schlesinger in 1909. The third component, λ Tau C, is orbiting...
reassigned from Scorpius to Libra and given the new names Sigma and Upsilon Librae.: p. 196 (To add to the confusion, the star now known as Omicron Scorpii...
Binary star system 3.581 Eta Pavonis Star 3.589 Upsilon Librae Star 3.59 Rho Boötis Star 3.59 Tau Orionis Star 3.59 Theta Ceti Star 3.60 Gamma Leporis Star...
Centre de données astronomiques de Strasbourg. Retrieved 2010-06-21. "Alpha Librae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2010-06-21...
remains uncertain. This group contains about 16 stars, including Alpha Librae, Alpha Cephei, Castor, Fomalhaut and Vega. All members of the group are...
of Field RV Tauri Stars. V. DS Aquarii, UY Arae, TW Camelopardalis, BT Librae, U Monocerotis, TT Ophiuchi, R Scuti, and RV Tauri". The Astrophysical Journal...
Commentary and Other Papers. 1998. Weiser. Editorial An Account of A∴ A∴ Liber Librae [The Book of the Balance] Liber Exercitiorum The Wizard Way. By Aleister...
Probationers.[This quote needs a citation] Unpublished. XXX 30 B Liber Librae, The Book of Balance. — Crowley: "An elementary course of morality suitable...
30 Tau 31 Tau ν Tau 40 Tau 45 Tau 46 Tau μ Tau 47 Tau 48 Tau 58 Tau 63 Tau 64 Tau θ1 Tau 46 Tau HIP 21029 HIP 21053 85 Tau 附耳 (Fù Ěr, Whisper) σ1 Tau 89...
of Field RV Tauri Stars. V. DS Aquarii, UY Arae, TW Camelopardalis, BT Librae, U Monocerotis, TT Ophiuchi, R Scuti, and RV Tauri". The Astrophysical Journal...
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