Delta Librae
{{short description|Binary star in the constellation Libra}}
{{Starbox begin
| name=δ Librae }}
{{Starbox image
| image = 250px
| caption = A light curve for Delta Librae, adapted from Shobbrook (2005)
}}
{{Starbox observe
| epoch=J2000
| constell=Libra
}}
{{Starbox character
| variable=Algol eclipsing
}}
{{Starbox astrometry
| parallax= 9.2824
| p_error=0.4725
}}
{{Starbox orbit
| axis_unitless = {{Val|12.73|0.34|ul=mas}}
| period_unitless = 2.3273543 days
}}
{{Starbox detail
| component1 = δ Lib A
| radius = {{Val|3.60|0.13}}
| mass = {{Val|3.78|0.13}}
| luminosity = {{Val|155|11|10}}
| temperature = {{Val|10520|110|fmt=commas}}
| component2 = δ Lib B
| mass2 = {{Val|1.50|0.04}}
| radius2 = {{val|3.79|0.04}}
| luminosity2 = {{Val|9.1|1.4|1.2}}
| temperature2 = {{Val|5150|175|fmt=commas}}
}}
{{Starbox catalog
| names=δ Lib, Zuben Elakribi, 19 Librae, {{nowrap|BD−07°3938}}, HD 132742, HIP 73473, HR 5586, SAO 140270
}}
{{Starbox reference
|Simbad=del+Lib
}}
{{Starbox end}}
Delta Librae, Latinized from δ Librae, is a variable star in the constellation Libra. It has the traditional name Zuben Elakribi, a variant of the traditional name of Gamma Librae. With μ Virginis it forms one of the Akkadian lunar mansions Mulu-izi(meaning "Man-of-fire").
δ Librae is approximately 350 light years from the Earth and the primary, component A, belongs to the spectral class B9.5V, indicating it is a B-type main-sequence star. It is visible to the naked eye with an apparent visual magnitude of 4.93 and is moving closer to the Sun with a radial velocity of −39 km/s. This is an Algol-like eclipsing binary star system, with a period of 2.3274 days and an eccentricity of 0.07. Its apparent magnitude varies from 4.91 to 5.90. The secondary is filling its Roche lobe and there is evidence of large-scale mass transfer in the past, with the secondary being more evolved than the primary despite now being less massive.
Along with λ Tauri, it was one of the first stars on which rotational line broadening was observed, by Frank Schlesinger in 1911.
References
{{Reflist|refs=
{{cite Gaia DR3|6332277920392457472}}
| last1=Schlesinger | first1=F. | year=1909 | bibcode=1911MNRAS..71..719S
| title=Rotation of Stars about their Axes
| journal=Monthly Notices of the Royal Astronomical Society | volume=71
| issue=9 | page=719 | doi=10.1093/mnras/71.9.719 | doi-access=free }}
| last1=Samus | first1=N. N. | last2=Kazarovets | first2=E. V.
| last3=Durlevich | first3=O. V. | last4=Kireeva | first4=N. N.
| last5=Pastukhova | first5=E. N. | title=General Catalogue of Variable Stars
| version=GCVS 5.1 | journal=Astronomy Reports | year=2017
| volume=61 | issue=1 | pages=80–88 | bibcode=2017ARep...61...80S
| url=http://www.sai.msu.su/gcvs/cgi-bin/search.cgi?search=del+lib
| accessdate=2018-01-07 | doi=10.1134/S1063772917010085
| s2cid=125853869 | url-access=subscription }}
| last1=Allen | first1=R. H.
| author-link=Richard Hinckley Allen
| year=1963
| title=Star Names: Their Lore and Meaning
| edition=rep.
| publisher=Dover Publications Inc.
| pages=277, 473
}}
| title=Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs
| author1=Rhee, Joseph H.|author2=Song, Inseok|author3=Zuckerman, B.|author4=McElwain, Michael
| journal=The Astrophysical Journal|volume=660|issue=2|pages=1556–1571|date=2007
| bibcode=2007ApJ...660.1556R|doi=10.1086/509912|arxiv=astro-ph/0609555|s2cid=11879505}}
| title=Secondaries of eclipsing binaries. I. Detection of the secondary of Delta Librae
| last1=Tomkin | first1=J. | journal=Astrophysical Journal | volume=221 | pages=608–615
| date=April 1978 | doi=10.1086/156064 | bibcode=1978ApJ...221..608T | doi-access=free }}
| 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 }}
| title=UBVRIJKL Photometry of the Bright Stars|author1=Johnson, H. L.
|journal=Communications of the Lunar and Planetary Laboratory|volume=4
| date=1966|page=99|bibcode=1966CoLPL...4...99J}}
| title=Del Lib |url = http://www.aavso.org/vsx/index.php?view=detail.top&oid=17591
| work=The International Variable Star Index
| publisher=AAVSO – American Association of Variable Star Observers
| access-date=27 September 2017 }}
| title=General catalogue of stellar radial velocities|author=Wilson, Ralph Elmer
| journal=Carnegie Institute Washington D.C. Publication|date=1953
| bibcode=1953GCRV..C......0W}}
| bibcode=1999MSS...C05....0H
| title=Michigan catalogue of two-dimensional spectral types for the HD Stars, Vol. 5
| journal=Michigan Spectral Survey|volume=5|author1=Houk, N.|author2=Swift, C.|year=1999}}
| bibcode=2002yCat.2237....0D
| title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system
| journal=CDS/ADC Collection of Electronic Catalogues
| volume=2237|author1=Ducati, J. R.|year=2002}}
| last1=Shobbrook |first1=R. R.
| title=Photometry of 20 eclipsing and ellipsoidal binary systems
| journal=The Journal of Astronomical Data |date=December 2005 |volume=11
|page=7
|bibcode=2005JAD....11....7S
| url=https://ui.adsabs.harvard.edu/abs/2005JAD....11....7S |access-date=10 July 2022}}
}}
{{Stars of Libra}}
{{DEFAULTSORT:Delta Librae}}
Category:B-type main-sequence stars
Category:Libra (constellation)