eta Virginis

{{Starbox begin

| name = η Virginis
(incl. Zaniah)

}}

{{Starbox image

| image=

{{Location mark

|image=Virgo constellation map.svg|alt=|float=center|width=280

|label=|position=right

|mark=Red circle.svg|mark_width=10|mark_link=η Virginis

|x=722|y=472

}}

|caption=Location of η Virginis (circled)

}}

{{Starbox observe

| epoch = J2000

| ra = {{RA|12|19|54.35783}}

| dec = {{DEC|-00|40|00.5095}}

| appmag_v = 3.890

| constell = Virgo

}}

{{Starbox character

| class = A2 V

| b-v = +0.029

| u-b = +0.055

| variable =

}}

{{Starbox astrometry

| radial_v = +2.3

| prop_mo_ra = −57.58

| prop_mo_dec = −25.19

| parallax = 13.264

| p_error = 0.161

| parallax_footnote =

| absmag_v = −0.66

}}

{{Starbox orbit

| reference =

| primary = η Vir Aa

| name = η Vir Ab

| period_unitless = {{val|71.7916|0.0006|u=days}}

| axis = {{val|0.00736|0.0006}}

| axis_unitless =

| eccentricity = {{val|0.244|0.007}}

| inclination = {{val|45.5|0.9}}

| node =

| periastron =

| periarg =

| periarg_primary =

| k1 =

| k2 =

}}

{{Starbox orbit

| reference =

| primary = η Vir A

| name = η Vir B

| period_unitless = {{val|7,896.2|0.2|u=days}}

| axis = {{val|0.133|0.001}}

| axis_unitless =

| eccentricity = {{val|0.087|0.002}}

| inclination = {{val|50.6|0.1}}

| node =

| periastron =

| periarg =

| periarg_primary =

| k1 =

| k2 =

}}

{{Starbox detail

| component1 = η Vir Aa

| age =

| metal_fe = +0.11

| gravity = 3.0

| mass = {{val|2.5039|0.1246}}

| radius =

| rotational_velocity = 18

| rotation =

| luminosity =

| temperature = 9,333

| component2 = η Vir Ab

| mass2 = {{val|1.8907|0.0932}}

}}

{{Starbox detail

| source =

| component1 = η Vir B

| age =

| metal_fe =

| gravity =

| mass = {{val|1.66|0.16}}

| radius =

| rotational_velocity =

| rotation =

| luminosity =

| temperature =

}}

{{Starbox catalog

| names = Zaniah, 15 Virginis, HR 4689, HD 107259, BD+00°2926, FK5 460, HIP 60129, SAO 138721, CCDM 12199-0040, WDS J12199-0040

}}

{{Starbox reference

| Simbad = eta+Vir

}}

Eta Virginis (η Virginis, abbreviated Eta Vir, η Vir) is a triple star system in the zodiac constellation of Virgo. From parallax measurements, it is about {{Convert|246|ly|pc|abbr=off|lk=on}} from the Sun. It has a combined apparent visual magnitude of 3.89, bright enough to be seen with the naked eye in dark skies.

The system consists of{{cite web | url=http://www.ctio.noao.edu/~atokovin/stars/stars.php?cat=HIP&number=60129 | title=Displaying next number in catalog HIP => 60129 | work=Multiple Star Catalog | access-date=2018-02-18 | archive-date=2020-10-03 | archive-url=https://web.archive.org/web/20201003042530/http://www.ctio.noao.edu/~atokovin/stars/stars.php?cat=HIP&number=60129 | url-status=dead }} a binary pair designated Eta Virginis A together with a third companion, Eta Virginis B. A's two components are themselves designated Eta Virginis Aa (officially named Zaniah {{IPAc-en|'|z|ei|n|i|@}}, the traditional name of the system){{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

}}{{cite web | url=https://www.iau.org/public/themes/naming_stars/ | title=Naming Stars |publisher=IAU.org |access-date=16 December 2017}} and Ab.

Nomenclature

η Virginis (Latinised to Eta Virginis) is the system's Bayer designation. The designations of the two constituents as Eta Virginis A and those of A's components - Eta Virginis Aa and Ab - derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).{{cite arXiv |title=On the naming convention used for multiple star systems and extrasolar planets |date=2010 |eprint=1012.0707 |class=astro-ph.SR |last1= Hessman |first1=F. V. |last2= Dhillon |first2=V. S. |last3= Winget |first3=D. E. |last4= Schreiber |first4=M. R. |last5= Horne |first5=K. |last6= Marsh |first6=T. R. |last7= Guenther |first7=E. |last8= Schwope |first8=A. |last9= Heber |first9=U. }}

It bore the traditional name Zaniah {{IPAc-en|z|@|'|n|aɪ|.|ə}}, derived from the Arabic زاوية zāwiyah "corner", the same source as Zavijava (Beta Virginis). In 2016, the IAU 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=. }} to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.{{cite web | url=https://www.iau.org/static/science/scientific_bodies/working_groups/280/wg-starnames-triennial-report-2015-2018.pdf | page=5 | title=WG Triennial Report (2015-2018) - Star Names |access-date=2018-07-14}} It approved the name Zaniah for the component Eta Virginis Aa on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.

In the catalogue of stars in the Calendarium of Al Achsasi Al Mouakket, this star was designated Thanih al Aoua, which was translated into Latin as Secunda Latratoris, meaning "the second barker".{{cite journal

| last=Knobel | first=E. B.

| title=Al Achsasi Al Mouakket, on a catalogue of stars in the Calendarium of Mohammad Al Achsasi Al Mouakket

| journal=Monthly Notices of the Royal Astronomical Society

| volume=55 | issue=8

| page=429 |date=June 1895

| bibcode=1895MNRAS..55..429K | doi=10.1093/mnras/55.8.429| doi-access=free}} This star, along with Beta Virginis (Zavijava), Gamma Virginis (Porrima), Delta Virginis (Minelauva) and Epsilon Virginis (Vindemiatrix), were Al ʽAwwāʼ, "the Barker".

In Chinese, {{lang|zh|太微左垣}} ({{lang|zh-Latn|Tài Wēi Zuǒ Yuán}}), meaning Left Wall of Supreme Palace Enclosure, refers to an asterism consisting of Eta Virginis, Gamma Virginis, Delta Virginis, Epsilon Virginis and Alpha Comae Berenices.{{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}}. Consequently, the Chinese name for Eta Virginis itself is {{lang|zh|太微左垣一}} ({{lang|zh-Latn|Tài Wēi Zuǒ Yuán yī}}, {{langx|en|the First Star of Left Wall of Supreme Palace Enclosure}}.),{{in lang|zh}} [http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_t_z.htm 香港太空館 - 研究資源 - 亮星中英對照表] {{webarchive |url=https://web.archive.org/web/20100819122914/http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_t_z.htm |date=August 19, 2010 }}, Hong Kong Space Museum. Accessed on line November 23, 2010. representing {{lang|zh|左執法}} ({{lang|zh-Latn|Zuǒzhífǎ}}), meaning "The Left Law Administrator".{{in lang|zh}} [http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/e_research_chinengstarzone_b.htm#SupremePalaceEnclosure English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name] {{webarchive |url=https://web.archive.org/web/20100810114313/http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/e_research_chinengstarzone_b.htm#SupremePalaceEnclosure |date=August 10, 2010 }}, Hong Kong Space Museum. Accessed on line November 23, 2010. 左執法 (Zuǒzhífǎ), spelled Tso Chih Fa by R.H. Allen, means "the Left-hand Maintainer of Law" [https://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Virgo*.html Richard Hinckley Allen: Star Names — Their Lore and Meaning: Virgo]

Properties

File:Virgo constellation PP3 map PL.svg

Eta Virginis looks single, but lunar occultations have shown it to be a very close triple star system consisting of two stars 0.6 AU apart, assuming a distance of 91 parsecs, with a third slightly more distant star. The inner pair is a spectroscopic binary that completes an orbit in 72 days. The inclination of this orbit was determined through interferometer observations to be 45.5°, allowing the masses of the two stars to be estimated. The primary star, Eta Virginis Aa, has a mass about 2.5 times the Sun's mass, while the secondary, Eta Virginis Ab, has 1.9 solar masses. The faint tertiary star, Eta Virginis B, orbits the inner group in a wider orbit over a period of 13.1 years.

Eta Virginis is 1.97 degrees north of the ecliptic, so it can be occulted by the Moon and (rarely) by planets. On October 12, 272 BC the ancient Greek astronomer Timocharis observed a conjunction of the star with Venus. The last occultation by a planet took place on September 27, 1843, also by Venus, which will occult it again on September 30, 2078.{{Citation needed|date=March 2025}}

Two degrees north-following of Eta Virginis is SS Virginis, a typical cool carbon star and one of the most red-colored stars in the equatorial sky.

References

{{reflist|30em|refs=

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

{{citation | last1=Fomenko | first1=A. T. | last2=Vi︠a︡cheslavovich | first2=Vladimir Kalashnikov | last3=Nosovskiĭ | first3=Gleb Vladimirovich | title=Geometrical and statistical methods of analysis of star configurations: dating Ptolemy's Almagest | page=215 | publisher=CRC Press | date=1993 | isbn=0-8493-4483-2 }}

{{citation | last1=Wolff | first1=Sidney Carne | title=A Spectroscopic and Photometric Study of the AP Stars | journal=Astrophysical Journal Supplement | volume=15 | page=21 |date=October 1967 | doi=10.1086/190162 | bibcode=1967ApJS...15...21W | doi-access=free }}

{{Ciation |last=Groenewegen |first=M. A. T. |date=2023-01-01 |title=Orbital parallax of binary systems compared to Gaia DR3 and the parallax zero-point offset at bright magnitudes |bibcode=2023A&A...669A...4G |arxiv=2210.14734 |journal=Astronomy and Astrophysics |volume=669 |pages=A4 |doi=10.1051/0004-6361/202244479 |issn=0004-6361}} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/A%2BA/669/A4&Name=12199-0040 Eta Virginis' database entry] at VizieR.

{{cite journal | last=Wilson | first=Ralph Elmer | date=1953 | title=General Catalogue of Stellar Radial Velocities | journal=Carnegie Institute Washington D.C. Publication | publisher=Carnegie Institution of Washington | location=Washington | bibcode=1953GCRV..C......0W }}

{{citation | last1=Royer | first1=F. | last2=Zorec | first2=J. | last3=Gómez | first3=A. E. | title=Rotational velocities of A-type stars. III. Velocity distributions | journal=Astronomy and Astrophysics | volume=463 | issue=2 | pages=671–682 |date=February 2007 | doi=10.1051/0004-6361:20065224 | bibcode=2007A&A...463..671R |arxiv = astro-ph/0610785 | s2cid=18475298 }}

{{citation | last1=Cousins | first1=A. W. J. | title=Standardization of Broadband Photometry of Equatorial Standards | journal=South African Astronomical Observatory Circulars | volume=8 | page=59 | date=1984 | bibcode=1984SAAOC...8...59C }}

{{citation | last1=Levato | first1=O. H. | title=Rotational Velocities and Spectral Types of Some A-Type Stars | journal=Publications of the Astronomical Society of the Pacific | volume=84 | issue=500 | page=584 |date=August 1972 | doi=10.1086/129336 | bibcode=1972PASP...84..584L | doi-access=free }}

{{citation | display-authors=1 | last1=Behr | first1=Bradford B. | last2=Cenko | first2=Andrew T. | last3=Hajian | first3=Arsen R. | last4=McMillan | first4=Robert S. | last5=Murison | first5=Marc | last6=Meade | first6=Jeff | last7=Hindsley | first7=Robert | title=Stellar Astrophysics with a Dispersed Fourier Transform Spectrograph. II. Orbits of Double-lined Spectroscopic Binaries | journal=The Astronomical Journal | volume=142 | issue=1 | page=6 |date=July 2011 | doi=10.1088/0004-6256/142/1/6 | bibcode=2011AJ....142....6B |arxiv = 1104.1447 | s2cid=119099887 }}

{{citation | title=eta Vir -- Spectroscopic binary | work=SIMBAD | publisher=Centre de Données astronomiques de Strasbourg | url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Eta+Virginis | access-date=2012-01-06 }}

{{citation | last=Allen | first=R. H. | date=1963 | author-link=Richard Hinckley Allen | title=Star Names: Their Lore and Meaning | url=https://archive.org/details/starnamestheirlo00alle/page/469 | access-date=2010-12-12 | edition=Reprint | publisher=Dover Publications Inc | location=New York | isbn=0-486-21079-0 | page=[https://archive.org/details/starnamestheirlo00alle/page/469 469] | url-access=registration }}

{{citation | first1=Olaf | last1=Pedersen | title=A Survey of the Almagest: With Annotation and New Commentary by Alexander Jones | series=Sources and Studies in the History of Mathematics and Physical Sciences | editor1-first=Alexander | editor1-last=Jones | edition=2nd | publisher=Springer | date=2010 | isbn=978-0-387-84825-9 | page=411 | url=https://books.google.com/books?id=8eaHxE9jUrwC&pg=PA411 }}

{{cite journal|bibcode=2003AJ....125.2630H|title=First Observations with a Co-phased Six-Station Optical Long-Baseline Array: Application to the Triple Star η Virginis|journal=The Astronomical Journal|volume=125|issue=5|pages=2630|last1=Hummel|first1=C. A.|last2=Benson|first2=J. A.|last3=Hutter|first3=D. J.|last4=Johnston|first4=K. J.|last5=Mozurkewich|first5=D.|last6=Armstrong|first6=J. T.|last7=Hindsley|first7=R. B.|last8=Gilbreath|first8=G. C.|last9=Rickard|first9=L. J.|last10=White|first10=N. M.|year=2003|doi=10.1086/374572|doi-access=free}}

{{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=. }}

}}