tau Librae

{{Starbox begin

| name = Tau Librae

}}

{{Starbox observe

| epoch = J2000.0

| equinox = J2000.0 (ICRS)

| constell = Libra

| ra = {{RA|15|38|39.36950}}

| dec = {{DEC|−29|46|39.8956}}

| appmag_v = 3.68

}}

{{Starbox character

| class = B2.5 V

| b-v = −0.179

| u-b = −0.717

| r-i =

| variable =

}}

{{Starbox astrometry

| radial_v = {{Val|+33.3|2.3}}

| prop_mo_ra = −22.08

| prop_mo_dec = −24.46

| parallax = 8.89

| p_error = 0.20

| parallax_footnote =

| absmag_v = −1.59

}}

{{Starbox orbit

| reference =

| period_unitless = 3.2907 d

| eccentricity = 0.28

| node = 114

| periastron = 2439272.312 JD

| k1 = 75

| k2 = 167

}}

{{Starbox detail

| source =

| component1 = τ Lib A

| mass = {{Val|7.25|0.49}}

| radius = 3.2

| luminosity_bolometric = 2,705

| temperature = 17,990

| gravity = 4.33

| metal_fe = +0.17

| rotational_velocity = 134

| age_myr = {{Val|31.5|5.6}}

}}

{{Starbox catalog

| names = τ Lib, 40 Lib, CD−29° 11837, HD 139365, HIP 76600, HR 5812, SAO 183649.

}}

{{Starbox reference

| Simbad = tau+Lib

}}

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. The distance to this system is around 367 light years, as determined from an annual parallax shift of 8.89 mas.

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. It is double-lined spectroscopic binary with an orbital period of just 3.3 days and an eccentricity of 0.28. The primary, component A, is a B-type main sequence star with a stellar classification of B2.5 V. It is estimated to hold more than seven times the mass of the Sun and have over three times the Sun's radius. It is only 31.5 million years old and is spinning relatively rapidly with a projected rotational velocity of 134 km/s. It is a heartbeat star system, with pulsations caused by tidal forces.{{cite journal|doi=10.1093/mnras/stac1816 |title=Pulsating B stars in the Scorpius–Centaurus Association with TESS |year=2022 |last1=Sharma |first1=Awshesh N. |last2=Bedding |first2=Timothy R. |last3=Saio |first3=Hideyuki |last4=White |first4=Timothy R. |journal=Monthly Notices of the Royal Astronomical Society |volume=515 |issue=1 |pages=828–840 |doi-access=free |arxiv=2203.02582 | bibcode=2022MNRAS.515..828S}}

The system is emitting an infrared excess, suggesting the presence of a circumstellar disk of material.

References

{{reflist|refs=

{{citation

| title=Validation of the new Hipparcos reduction

| last1=van Leeuwen | first1=F.

| journal=Astronomy and Astrophysics

| volume=474 | issue=2 | pages=653–664 | date=2007

| arxiv=0708.1752 | bibcode=2007A&A...474..653V

| doi=10.1051/0004-6361:20078357 | s2cid=18759600 | postscript=. }}

{{citation

| title=XHIP: An extended hipparcos compilation

| last1=Anderson | first1=E. | last2=Francis | first2=Ch.

| journal=Astronomy Letters

| volume=38 | issue=5 | pages=331 | year=2012

| bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015

| arxiv=1108.4971 | s2cid=119257644 | postscript=. }}

{{citation

| first1=L. E. | last1=Pasinetti-Fracassini | first2=L. | last2=Pastori

| first3=S. | last3=Covino | first4=A. | last4=Pozzi

| title=Catalog of Apparent Diameters and Absolute Radii of Stars (CADARS)

| edition=3rd | display-authors=1 | postscript=.

| journal=Astronomy and Astrophysics

| volume=367 | pages=521–524 | date=February 2001

| doi=10.1051/0004-6361:20000451 | bibcode=2001A&A...367..521P |arxiv = astro-ph/0012289 | s2cid=425754 }}

{{citation

| title=A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun

| journal=Monthly Notices of the Royal Astronomical Society

| volume=410 | issue=1 | pages=190–200 | date=January 2011

| doi=10.1111/j.1365-2966.2010.17434.x | doi-access=free | bibcode=2011MNRAS.410..190T

| arxiv=1007.4883 | s2cid=118629873 | postscript=. }}

{{citation

| display-authors=1 | last1=Hohle | first1=M. M.

| last2=Neuhäuser | first2=R. | last3=Schutz | first3=B. F.

| title=Masses and luminosities of O- and B-type stars and red supergiants

| journal=Astronomische Nachrichten

| volume=331 | issue=4 | page=349 | date=April 2010

| doi=10.1002/asna.200911355 | bibcode=2010AN....331..349H

| arxiv=1003.2335 | s2cid=111387483 | postscript=. }}

{{citation

| title=Spectroscopic metallicities of Vega-like stars

| last1=Saffe | first1=C. | last2=Gómez | first2=M.

| last3=Pintado | first3=O. | last4=González | first4=E.

| journal=Astronomy and Astrophysics | postscript=.

| volume=490 | issue=1 | pages=297–305 | date=October 2008

| doi=10.1051/0004-6361:200810260 | bibcode=2008A&A...490..297S |arxiv = 0805.3936 | s2cid=15059920 }}

{{citation

| display-authors=1

| last1=Jilinski | first1=E. | last2=Daflon | first2=S.

| last3=Cunha | first3=K. | last4=de La Reza | first4=R.

| title=Radial velocity measurements of B stars in the Scorpius–Centaurus association

| journal=Astronomy and Astrophysics

| volume=448 | issue=3 |date=March 2006 | pages=1001–1006

| doi=10.1051/0004-6361:20041614 | bibcode=2006A&A...448.1001J

| arxiv=astro-ph/0601643 | s2cid=17818058 | postscript=. }}

{{citation

| display-authors=1 | last1=Pourbaix | first1=D.

| last2=Tokovinin | first2=A. A. | last3=Batten | first3=A. H.

| last4=Fekel | first4=F. C. | last5=Hartkopf | first5=W. I.

| last6=Levato | first6=H. | last7=Morrell | first7=N. I.

| last8=Torres | first8=G. | last9=Udry | first9=S.

| title=SB9: The ninth catalogue of spectroscopic binary orbits

| journal=Astronomy and Astrophysics

| volume=424 | issue=2 | pages=727–732 | year=2004

| bibcode=2004A&A...424..727P | doi=10.1051/0004-6361:20041213

| arxiv=astro-ph/0406573 | s2cid=119387088 | postscript=. }}

{{citation

| title=B Star Rotational Velocities in h and χ Persei: A Probe of Initial Conditions during the Star Formation Epoch?

| display-authors=1 | last1=Strom | first1=Stephen E.

| last2=Wolff | first2=Sidney C. | last3=Dror | first3=David H. A.

| journal=The Astronomical Journal

| volume=129 | issue=2 | pages=809–828 | date=February 2005

| doi=10.1086/426748 | bibcode=2005AJ....129..809S | postscript=. |arxiv = astro-ph/0410337 | s2cid=15059129 }}

{{citation

| last1=Hiltner | first1=W. A.

| last2=Garrison | first2=R. F.

| last3=Schild | first3=R. E. | date=July 1969

| title=MK Spectral Types for Bright Southern OB Stars

| journal=Astrophysical Journal | volume=157

| pages=313–326 | doi=10.1086/150069

| bibcode=1969ApJ...157..313H | postscript=. | doi-access=free }}

{{citation

| last1=Gutierrez-Moreno | first1=Adelina | last2=Moreno | first2=Hugo

| title=A photometric investigation of the Scorpio-Centaurus association

| journal=Astrophysical Journal Supplement | postscript=.

| volume=15 | page=459 | date=June 1968

| bibcode=1968ApJS...15..459G | doi=10.1086/190168 | doi-access=free }}

{{cite simbad

| title=tau Lib

| accessdate=2017-01-30 | postscript=. }}

}}

External links

{{citation

| first1=James B. | last1=Kaler | date=May 17, 2013

| title=Tau Librae | work=Stars | publisher=University of Illinois

| url=http://stars.astro.illinois.edu/sow/taulib.html

| accessdate=2017-02-02 | postscript=. }}

Category:B-type main-sequence stars

Librae, Tau

Category:Libra (constellation)

Category:Upper Centaurus Lupus

Category:Spectroscopic binaries