lambda Librae

{{short description|Binary star system in the constellation Libra}}

{{Starbox begin

| name = Lambda Librae

}}

{{Starbox image

| image = 250px

| caption = A light curve for Lambda Librae, adapted from Wraight et al. (2012)

}}

{{Starbox observe

| epoch = J2000.0

| equinox = J2000.0 (ICRS)

| constell = Libra

| ra = {{RA|15|53|20.05463}}

| dec = {{DEC|−20|10|01.4177}}

| appmag_v = 5.03

}}

{{Starbox character

| class = B3 V

| b-v = −0.023

| u-b = −0.584

| r-i =

| variable = Rotating ellipsoidal

}}

{{Starbox astrometry

| radial_v = {{Val|−2.0|0.5}}

| prop_mo_ra = −9.81

| prop_mo_dec = −26.85

| parallax = 10.54

| p_error = 0.91

| parallax_footnote =

| absmag_v = 0.56

}}

{{Starbox orbit

| reference =

| period_unitless = {{Val|14.4829|0.0004|u=d}}

| eccentricity = {{Val|0.27|0.09}}

| periastron = {{nowrap|2435172.380 ± 0.664 JD}}

| periarg = {{Val|217|17}}

| k1 = {{Val|28.5|3.3}}

}}

{{Starbox detail

| source =

| mass = {{Val|5.01|0.26}}

| radius = 3.9

| luminosity = 743

| temperature = 18,700

| gravity = 4.75

| metal_fe = −0.27

| rotational_velocity = 155

| age_myr = 282

}}

{{Starbox catalog

| names = λ Lib, 45 Lib, BD−19°4249, FK5 1415, HD 142096, HIP 77811, HR 5902, SAO 183895.

}}

{{Starbox reference

| Simbad = lam+Lib

}}

λ Librae (Latinised as Lambda Librae) is the Bayer designation for a binary star system in the zodiac constellation of Libra. It can be faintly seen with the naked eye, having an apparent visual magnitude of 5.03. With an annual parallax shift of 10.54 mas, it is roughly 310 light years from the Sun. At that distance, the visual magnitude of this system is diminished by an extinction factor of 0.22 due to interstellar dust. It is 0.1 degree north of the ecliptic.

This is a single-lined spectroscopic binary star system with an orbital period of 14.48 days and an eccentricity of 0.27. The visible component is a B-type main sequence star with a stellar classification of B3 V. It is a helium-weak chemically peculiar star and a rotating ellipsoidal variable. The star has an estimated 3.9 times the radius of the Sun and five times the Sun's mass. This is a candidate Vega-like star, meaning that it shows an infrared excess characteristic of a circumstellar debris disk. The system is a source of X-ray emission.

References

{{reflist|refs=

{{cite journal

| title=A photometric study of chemically peculiar stars with the STEREO satellites – I. Magnetic chemically peculiar stars

| journal=Monthly Notices of the Royal Astronomical Society |date=February 2012

}}

{{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=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

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

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

| title=Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) – Third edition – Comments and statistics

| journal=Astronomy and Astrophysics | display-authors=1

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

| issue=2 | doi=10.1051/0004-6361:20000451 | bibcode=2001A&A...367..521P

| arxiv=astro-ph/0012289 | s2cid=425754 | postscript=. }}

{{citation

| title=The ROSAT all-sky survey catalogue of optically bright OB-type stars

| last1=Berghoefer | first1=T. W.

| last2=Schmitt | first2=J. H. M. M. | last3=Cassinelli | first3=J. P.

| journal=Astronomy and Astrophysics Supplement

| volume=118 | pages=481–494 | date=September 1996

| issue=3 | doi=10.1051/aas:1996213 | bibcode=1996A&AS..118..481B | postscript=. | doi-access=free }}

{{citation

| title=A Catalogue of Correlations Between Eclipsing Binaries and Other Categories of Double Stars

| last1=Hoffleit | first1=Dorrit

| journal=The Journal of the American Association of Variable Star Observers

| volume=24 | issue=2 | pages=105–116 | year=1996

| bibcode=1996JAVSO..24..105H | postscript=. }}

{{citation

| title=S_B⁹: The ninth catalogue of spectroscopic binary orbits

| journal=Astronomy & Astrophysics

|display-authors=5 | 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.

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

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

| arxiv=astro-ph/0406573 | s2cid=119387088

| postscript=. }}

{{citation

| last1=Renson | first1=P. | last2=Manfroid | first2=J.

| title=Catalogue of Ap, HgMn and Am stars

| journal=Astronomy and Astrophysics | postscript=.

| volume=498 | issue=3 | pages=961–966 |date=May 2009

| doi=10.1051/0004-6361/200810788 | bibcode=2009A&A...498..961R | url=https://zenodo.org/record/890529| doi-access=free }}

{{citation

| 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=Spatial distribution and kinematics of OB stars

| last1=Gontcharov | first1=G. A.

| journal=Astronomy Letters

| volume=38 | issue=11 | pages=694–706 | date=November 2012

| doi=10.1134/S1063773712110035 | bibcode=2012AstL...38..694G

| arxiv=1606.09028 | s2cid=119108982 | postscript=. }}

{{citation

| last1=de Bruijne | first1=J. H. J. | last2=Eilers | first2=A.-C.

| title=Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project

| journal=Astronomy & Astrophysics

| volume=546 | id=A61 | pages=14 | date=October 2012

| doi=10.1051/0004-6361/201219219 | bibcode=2012A&A...546A..61D

| arxiv=1208.3048 | s2cid=59451347 | postscript=. }}

{{citation

| last1=Houk | first1=Nancy | last2=Smith-Moore | first2=M.

| title=Michigan catalogue of two-dimensional spectral types for the HD stars

| volume=4 | publication-place=Ann Arbor | year=1978

| publisher=Dept. of Astronomy, University of Michigan

| bibcode=1988mcts.book.....H | postscript=. }}

{{citation

| display-authors=1 | last1=Abt | first1=Helmut A.

| last2=Levato | first2=Hugo | last3=Grosso | first3=Monica

| title=Rotational Velocities of B Stars

| journal=The Astrophysical Journal

| bibcode=2002ApJ...573..359A | doi=10.1086/340590 | 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 }}

{{citation

| title=lam Lib -- Spectroscopic binary

| work=SIMBAD Astronomical Database

| publisher=Centre de Données astronomiques de Strasbourg

| url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=lam+Lib

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

}}

Category:B-type main-sequence stars

Category:Spectroscopic binaries

Category:Helium-weak stars

Category:Libra (constellation)

Category:Rotating ellipsoidal variables