Epoch J2000 Equinox J2000
|Right ascension||12h 55m 36.20861s|
|Declination||+3° 23′ 50.8932″|
|Apparent magnitude (V)||3.402|
|Spectral type||M3 III|
|U−B color index||+1.825|
|B−V color index||+1.565|
|Radial velocity (Rv)||–18.14 ± 0.55 km/s|
|Proper motion (μ)||RA: –469.99 mas/yr
Dec.: –52.83 mas/yr
|Parallax (π)||16.44 ± 0.22 mas|
|Distance||198 ± 3 ly
(60.8 ± 0.8 pc)
|Absolute magnitude (MV)||–2.4 ± 0.3|
|Mass||1.4 ± 0.3 M☉|
|Surface gravity (log g)||1.0 cgs|
|Metallicity [Fe/H]||–0.16 dex|
|Rotational velocity (v sin i)||6.0 km/s|
Delta Virginis (δ Vir, δ Virginis) is a star in the zodiac constellation of Virgo. It has the traditional name Auva. With an apparent visual magnitude of 3.4, 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 Earth.
The spectrum of this star matches a stellar classification of M3 III, 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. Even though it has just 1.4 times the mass of the Sun, this wide envelope gives it a luminosity of roughly 468 times the Sun's. This energy is being radiated from a relatively cool outer atmosphere that has an effective temperature of nearly 4,000 K. It is this cool temperature that gives it the orange-red glow of an M-type star.
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. 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. 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.
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.
The medieval names Auva, Al Awwa, and Minelauva are from the Arabic عوى cawwa’, meaning "barking (dog)". This star, along with β Vir(Zavijava), γ Vir (Porrima), η Vir (Zaniah) and ε Vir (Vindemiatrix), were Al ʽAwwāʼ, the Barker.
In Chinese, 太微左垣 (Tài Wēi Zuǒ Yuán), meaning Left Wall of Supreme Palace Enclosure, refers to an asterism consisting of δ Virginis, η Virginis, γ Virginis, ε Virginis and α Comae Berenices. Consequently, δ 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.), representing 東次相 (Dōngcìxiāng), meaning The Second Eastern Minister. 東次相 (Dōngcìxiāng), westernized into Tsze Seang by R.H. Allen and the meaning is "the Second Minister of State" 
- van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357
- 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
- Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics 352: 495–507, Bibcode:1999A&A...352..495M
- 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
- Tsuji, T. (October 2008), "Cool luminous stars: the hybrid nature of their infrared spectra", Astronomy and Astrophysics 489 (3): 1271–1289, arXiv:0807.4387, Bibcode:2008A&A...489.1271T, doi:10.1051/0004-6361:200809869
- "del Vir -- Variable Star", SIMBAD (Centre de Données astronomiques de Strasbourg), retrieved 2012-02-07
- "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, retrieved 2012-01-16
- 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:0908.3228, Bibcode:2009MNRAS.400.1945T, doi:10.1111/j.1365-2966.2009.15588.x
- 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/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272
- Kaler, James B., "Delta Virginis", Stars (University of Illinois), retrieved 2012-02-07
- 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
- (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.
- (Chinese) 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.
- (Chinese) English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name, Hong Kong Space Museum. Accessed on line November 23, 2010.
- Richard Hinckley Allen: Star Names — Their Lore and Meaning: Virgo