Delta Virginis

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Delta Virginis
Diagram showing star positions and boundaries of the Virgo constellation and its surroundings
Cercle rouge 100%.svg
Location of δ Virginis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Virgo
Right ascension 12h 55m 36.20861s[1]
Declination +3° 23′ 50.8932″[1]
Apparent magnitude (V) 3.32 - 3.40[2]
Characteristics
Spectral type M3 III[3]
U−B color index +1.825[4]
B−V color index +1.565[4]
Variable type Semiregular[2]
Astrometry
Radial velocity (Rv) –18.14 ± 0.55[5] km/s
Proper motion (μ) RA: –469.99[1] mas/yr
Dec.: –52.83[1] mas/yr
Parallax (π) 16.44 ± 0.22[1] mas
Distance 198 ± 3 ly
(60.8 ± 0.8 pc)
Absolute magnitude (MV) –2.4 ± 0.3[6]
Details
Mass 1.4 ± 0.3[6] M
Radius 48[5] R
Luminosity 468[5] L
Surface gravity (log g) 1.0[5] cgs
Temperature 3,999[5] K
Metallicity [Fe/H] –0.16[5] dex
Rotational velocity (v sin i) 6.0[5] km/s
Other designations
Minelauva, 43 Virginis, BD+04° 2669, FK5 484, HD 112300, HIP 63090, HR 4910, LTT 13714, SAO 119674, WDS 12556+0324.[7]
Database references
SIMBAD data

Delta Virginis (δ Virginis, abbreviated Del Vir, δ Vir), also named Minelauva,[8] is a star in the zodiac constellation of Virgo. With an apparent visual magnitude of 3.4,[4] this star is bright enough to be seen with the naked eye. Based upon parallax measurements, it is located at a distance of about 198 light-years (61 parsecs) from the Sun.[1]

Nomenclature[edit]

δ Virginis (Latinised to Delta Virginis) is the star's Bayer designation.

It bore the traditional, medieval names Auva and Minelauva[9] from the Arabic عوى cawwa’, meaning "barking (dog)". In 2016, the IAU organized a Working Group on Star Names (WGSN)[10] to catalog and standardize proper names for stars. The WGSN approved the name Minelauva for this star on 30 June 2017 and it is now so included in the List of IAU-approved Star Names.[8]

This star, along with Beta Virginis (Zavijava), Gamma Virginis, Eta Virginis (Zaniah) and Epsilon Virginis (Vindemiatrix), were Al ʽAwwāʼ, 'the Barker'.[11]

In Chinese, 太微左垣 (Tài Wēi Zuǒ Yuán), meaning Left Wall of Supreme Palace Enclosure, refers to an asterism consisting of Delta Virginis, Eta Virginis, Gamma Virginis, Epsilon Virginis and Alpha Comae Berenices.[12] Consequently, Delta Virginis itself is known as 太微左垣三 (Tài Wēi Zuǒ Yuán sān, English: the Third Star of Left Wall of Supreme Palace Enclosure),[13] representing 東次相 (Dōngcìxiāng), meaning 'The Second Eastern Minister'.[14] 東次相 (Dōngcìxiāng), westernized into Tsze Seang by R.H. Allen and meaning "the Second Minister of State".[15]

Properties[edit]

The spectrum of Delta Virginis matches a stellar classification of M3 III,[3] which places it among the category of evolved stars called red giants. Indeed, the outer atmosphere of this star has expanded to around 48 times the radius of the Sun.[5] Even though it has just 1.4 times the mass of the Sun,[6] this wide envelope gives it a luminosity of roughly 468 times the Sun's.[5] This energy is being radiated from a relatively cool outer atmosphere that has an effective temperature of nearly 4,000 K.[5] It is this cool temperature that gives it the orange-red glow of an M-type star.[16]

The outer envelope of this star is undergoing a type of pulsation that occurs in a class of variable stars known as semiregular variables and its brightness varies from magnitude +3.32 to +3.40.[2] Based upon frequency analysis of the observed light curve, the star's variability exhibits multiple periods of pulsation. The detected periods are 13.0, 17.2, 25.6, 110.1 and 125.8 days.[2] This is a high-velocity star with a peculiar velocity of more than 30 km s−1 relative to the mean motion of other stars in the vicinity.[17]

Delta Virginis is a possible binary star, as an 11th magnitude star is located at an angular separation of 80 arcseconds. This K-type dwarf may have an orbital period of over 200,000 years, but this has not been confirmed.[18]

References[edit]

  1. ^ a b c d e f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357 
  2. ^ a b c d Tabur, V.; et al. (December 2009), "Long-term photometry and periods for 261 nearby pulsating M giants", Monthly Notices of the Royal Astronomical Society, 400 (4): 1945–1961, arXiv:0908.3228Freely accessible, Bibcode:2009MNRAS.400.1945T, doi:10.1111/j.1365-2966.2009.15588.x 
  3. ^ a b Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics, 352: 495–507, Bibcode:1999A&A...352..495M 
  4. ^ a b c Celis S., L. (October 1975), "Photoelectric photometry of late-type variable stars", Astronomy and Astrophysics Supplement Series, 22: 9–17, Bibcode:1975A&AS...22....9C 
  5. ^ a b c d e f g h i j Massarotti, Alessandro; et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209 
  6. ^ a b c Tsuji, T. (October 2008), "Cool luminous stars: the hybrid nature of their infrared spectra", Astronomy and Astrophysics, 489 (3): 1271–1289, arXiv:0807.4387Freely accessible, Bibcode:2008A&A...489.1271T, doi:10.1051/0004-6361:200809869 
  7. ^ "del Vir -- Variable Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2012-02-07 
  8. ^ a b "Naming Stars". IAU.org. Retrieved 16 December 2017. 
  9. ^ Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally published in: 1964BS....C......0H. 5050. Bibcode:1995yCat.5050....0H. 
  10. ^ "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016. 
  11. ^ Allen, R. H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York, NY: Dover Publications Inc, p. 469, ISBN 0-486-21079-0, retrieved 2010-12-12 
  12. ^ (in Chinese) 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.
  13. ^ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 Archived 2010-08-11 at the Wayback Machine., Hong Kong Space Museum. Accessed on line November 23, 2010.
  14. ^ (in Chinese) English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name Archived August 10, 2010, at the Wayback Machine., Hong Kong Space Museum. Accessed on line November 23, 2010.
  15. ^ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Virgo
  16. ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on 2012-03-10, retrieved 2012-01-16 
  17. ^ Famaey, B.; et al., "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430: 165–186, arXiv:astro-ph/0409579Freely accessible, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272 
  18. ^ Kaler, James B., "Delta Virginis", Stars, University of Illinois, retrieved 2012-02-07 

External links[edit]