Beta Librae

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Star in the constellation Libra

title: "Beta Librae" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["bayer-objects", "b-type-main-sequence-stars", "libra-(constellation)", "stars-with-proper-names", "flamsteed-objects", "hipparcos-objects", "suspected-variables", "bright-star-catalogue-objects", "henry-draper-catalogue-objects", "durchmusterung-objects", "population-i-stars", "lucidae"] description: "Star in the constellation Libra" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/Beta_Librae" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Star in the constellation Libra ::

| name = Beta Librae | image = [[File:Libra IAU.svg|250px|alt=Diagram showing star positions and boundaries of the Libra constellation and its surroundings]] [[File:Cercle rouge 100%.svg|12px]] | caption = The position of β Librae (circled) | epoch = J2000 | ra = | dec = | appmag_v = 2.61 | constell = Libra | class = B8 V | b-v = −0.106 | u-b = −0.359 | variable = Suspected |type=Main sequence}} | radial_v = −35.2 | prop_mo_ra = −98.10 | prop_mo_dec = −19.65 | parallax = 17.62 | p_error = 0.16 | parallax_footnote = | absmag_v = −1.16 | mass = | radius = 4.77 | luminosity = 413 | temperature = 11,900 | metal_fe = 0.33 | rotational_velocity = 250 | age_myr = | names = Zubeneschamali, Kiffa Australis, Lanx Borealis, β Lib, 27 Librae, BD−08°3935, FK5 564, HD 135742, HIP 74785, HR 5685, NSV 7009, SAO 140430 |Simbad=bet+Lib

Beta Librae is the brightest star in the zodiac constellation of Libra. It has the proper name Zubeneschamali ,{{cite book |last1=Kunitzsch |first1=Paul |last2=Smart |first2=Tim |date = 2006 |edition = 2nd rev. |title = A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations |publisher = Sky Pub |location = Cambridge, Massachusetts |isbn = 978-1-931559-44-7

The apparent visual magnitude of this star is 2.6. According to Eratosthenes, Beta Librae was observed to be brighter than Antares. Ptolemy, 350 years later, said it was as bright as Antares. The discrepancy may be due to Antares becoming brighter, but this is not known for certain. It could simply be caused by Beta Librae being a variable star, showing a present-day variability of 0.03 of a magnitude.

Name

β Librae (Latinised to Beta Librae) is the star's Bayer designation. It can also be abbreviated as Beta Lib or β Lib.

It bore the traditional name Zubeneschamali (less common renderings, or corruptions, are Zuben Eschamali, Zuben el Chamali, Zubenesch, Zubenelg), derived from the Arabic الزُّبَانَى الشَمَالِي (al-zubānā al-šamāliyy) meaning "the northern claw". This name originated in a time when Libra was viewed as representing the "claws of the scorpion". There was also Kiffa Borealis, from the Arabic al-kiffah aš-šamāliyy "the northern pan (of the scales)" and the Latin equivalent Lanx Borealis. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN){{citation | url=https://www.iau.org/science/scientific_bodies/working_groups/280/ | title=IAU Working Group on Star Names (WGSN) | publisher=International Astronomical Union | access-date=22 May 2016 | postscript=. | archive-date=10 June 2016 | archive-url=https://web.archive.org/web/20160610172014/https://www.iau.org/science/scientific_bodies/working_groups/280/ | url-status=dead

In Chinese, 氐宿 (Dī Xiù), meaning Root, refers to an asterism consisting of β Librae, α2 Librae, ι Librae and γ Librae. Consequently, the Chinese name for β Librae itself is 氐宿四 (Dī Xiù sì), "the Fourth Star of Root".

Properties

Based upon the features of its spectrum, Beta Librae has a stellar classification of B8 V, making it a B-type main-sequence star. It is 4.77 times larger than the Sun, about 410 times more luminous, and has a surface effective temperature of , double that of the Sun. This high temperature produces light with a simple spectrum, making it ideal for examining the interstellar gas and dust between Earth and the star. Like many stars of its kind, it is spinning rapidly, over 100 times faster than the Sun with a projected rotational velocity of 250 km·s−1.

This type of massive, hydrogen-fusing star often appears blue-white, and is usually stated to be white or bluish by modern observers, but earlier observers often described Beta Librae as the only greenish star visible to the naked eye. There seems to be no generally accepted explanation for why some observers see it as green. The small periodic variations in the magnitude of Beta Librae suggest the presence of a companion star which is not directly observable from Earth. However, it is categorized as a single star.

In around 200 million years, Beta Librae will have exhausted the supply of hydrogen in its core and become a giant star similar to Beta Herculis, which had a similar initial mass.

References

| title=Validation of the new Hipparcos reduction | last=van Leeuwen | first=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 |date=November 2007 | pages=653–664 | doi=10.1051/0004-6361:20078357 | s2cid=18759600 | bibcode=2007A&A...474..653V |arxiv = 0708.1752 }}

| last=Burnham | first=Robert Jr. | author-link=Robert Burnham Jr. | title=Burnham's Celestial Handbook | volume=2 | publisher=Dover Publications | year=1978 | location=New York | isbn=0-486-23568-8 | page=1105 | url=https://books.google.com/books?id=lNcbcoWiY5oC&pg=PA1105 }}

| title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | volume=38 | issue=5 | page=331 | year=2012 | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | s2cid=119257644 | postscript=. }}

References

  1. "IAU Catalog of Star Names".
  2. {{in lang. zh ''中國星座神話'', written by 陳久金. Published by 台灣書房出版有限公司, 2005, {{ISBN. 978-986-7332-25-7.
  3. {{in lang. zh [http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_ala_alz.htm 香港太空館 - 研究資源 - 亮星中英對照表] {{webarchive. link. (2008-10-25 , Hong Kong Space Museum. Accessed on line November 23, 2010.)
  4. "kornephoros".
  5. (2017-10-01). "Fundamental parameters and infrared excesses of Tycho-Gaia stars". Monthly Notices of the Royal Astronomical Society.
  6. (1999). "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions". Astronomisches Rechen-Institut Heidelberg.
  7. (August 2011). "High-contrast Imaging Search for Planets and Brown Dwarfs around the Most Massive Stars in the Solar Neighborhood". The Astrophysical Journal.
  8. (July 2002). "Rotational Velocities of B Stars". The Astrophysical Journal.
  9. (June 1968). "A photometric investigation of the Scorpio-Centaurus association".
  10. "bet Lib".
  11. (September 2008). "A catalogue of multiplicity among bright stellar systems". [[Monthly Notices of the Royal Astronomical Society]].
  12. (2006). "Zubeneschamali". [[University of Illinois]].
  13. Mark Fisher. (1999–2006). "Zuben Elschemali". The Electronic Sky.
  14. (1727). "Tabulae Astronomicae". Parisiis : Apud Montalant, typographum & bibliopolam ....
  15. AAS. (2006). "LIBRA – A Balanced View (page 7 of PDF)". Auckland Astronomical Society.

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bayer-objectsb-type-main-sequence-starslibra-(constellation)stars-with-proper-namesflamsteed-objectshipparcos-objectssuspected-variablesbright-star-catalogue-objectshenry-draper-catalogue-objectsdurchmusterung-objectspopulation-i-starslucidae