Astronomy:Delta Virginis
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Virgo |
| Right ascension | 12h 55m 36.20861s[1] |
| Declination | +3° 23′ 50.8932″[1] |
| Apparent magnitude (V) | 3.32 - 3.40[2] |
| Characteristics | |
| Evolutionary stage | AGB[3] |
| Spectral type | M1 III[4] |
| U−B color index | +1.825[5] |
| B−V color index | +1.565[5] |
| Variable type | Semiregular[2] |
| Astrometry | |
| Radial velocity (Rv) | −18.14±0.55[6] 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 | 202.36±11.05 ly (62.07±3.39 pc) |
| Absolute magnitude (MV) | 2.4±0.3[7] |
| Details[4] | |
| Mass | 1.4±0.3[7][4] M☉ |
| Radius | 65.8 R☉ |
| Luminosity | 502.57 L☉ |
| Surface gravity (log g) | 0.8 cgs |
| Temperature | 3657 K |
| Metallicity [Fe/H] | −0.06 dex |
| Rotational velocity (v sin i) | 8.1 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Delta Virginis (δ Virginis, abbreviated Del Vir, δ Vir), formally named Minelauva /ˌmɪnəˈlɔːvə/,[9] is a star in the zodiac constellation of Virgo. With an apparent visual magnitude of 3.4,[5] this star is bright enough to be seen with the naked eye. It is located at a distance of about 202 light-years (62 parsecs) from the Sun.[10]
Nomenclature
δ Virginis (Latinised to Delta Virginis) is the star's Bayer designation.
It bore the traditional, medieval names Auva and Minelauva[11] from the Arabic من العواء min al-ʽawwāʼ, meaning "in the lunar mansion of ʽawwaʼ" (a name of unknown meaning).[12] In 2016, the IAU organized a Working Group on Star Names (WGSN)[13] 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.[9]
This star, along with Beta Virginis (Zavijava), Gamma Virginis (Porrima), Eta Virginis (Zaniah) and Epsilon Virginis (Vindemiatrix), were Al ʽAwwāʼ, 'the Barker'.[14]
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.[15] Consequently, the Chinese name for Delta Virginis itself is 太微左垣三 (Tài Wēi Zuǒ Yuán sān, English: the Third Star of Left Wall of Supreme Palace Enclosure),[16] representing 東次相 (Dōngcìxiāng), meaning 'The Second Eastern Minister'.[17] 東次相 (Dōngcìxiāng), westernized into Tsze Seang by R.H. Allen and meaning "the Second Minister of State".[18]
Properties
The spectrum of Delta Virginis matches a stellar classification of M1 III,[4] which places it among the category of evolved stars called red giants. Indeed, the outer atmosphere of this star has expanded to around 66 times the radius of the Sun.[4] Even though it has just 1.4 times the mass of the Sun,[7][4] this wide envelope gives it a luminosity of roughly 500 times the Sun's.[4] This energy is being radiated from a relatively cool outer atmosphere that has an effective temperature of 3,657 K.[4] It is this cool temperature that gives it the orange-red glow of an M-type star.[19]
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.[21]
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.[22]
Substellar companion
A 2023 study detected radial velocity variations in Delta Virginis (HD 112300), showing evidence of a substellar companion, likely a brown dwarf.[23]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥15.83+2.33 −2.74 MJ |
1.33+0.08 −0.11 |
466.63+1.47 −1.28 |
0.36+0.06 −0.11 |
— | — |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V
- ↑ 2.0 2.1 2.2 2.3 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, doi:10.1111/j.1365-2966.2009.15588.x, Bibcode: 2009MNRAS.400.1945T
- ↑ Eggen, Olin J. (July 1992), "Asymptotic giant branch stars near the sun", Astronomical Journal 104 (1): 275–313, doi:10.1086/116239, Bibcode: 1992AJ....104..275E.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Lee, Byeong-Cheol; Do, Hee-Jin; Park, Myeong-Gu; Lim, Beomdu; Choi, Yeon-Ho; Koo, Jae-Rim; Bang, Tae-Yang; Oh, Hyeong-Ill et al. (2023-10-01). "Long-period radial velocity variations of nine M red giants. The detection of substellar companions around HD 6860 and HD 112300". Astronomy and Astrophysics 678: A106. doi:10.1051/0004-6361/202243725. ISSN 0004-6361. https://ui.adsabs.harvard.edu/abs/2023A&A...678A.106L.
- ↑ 5.0 5.1 5.2 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
- ↑ 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, doi:10.1088/0004-6256/135/1/209, Bibcode: 2008AJ....135..209M
- ↑ 7.0 7.1 7.2 Tsuji, T. (October 2008), "Cool luminous stars: the hybrid nature of their infrared spectra", Astronomy and Astrophysics 489 (3): 1271–1289, doi:10.1051/0004-6361:200809869, Bibcode: 2008A&A...489.1271T
- ↑ "del Vir -- Variable Star", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Delta+Virginis, retrieved 2012-02-07
- ↑ 9.0 9.1 "Naming Stars". IAU.org. https://www.iau.org/public/themes/naming_stars/.
- ↑ "HD 112300 | NASA Exoplanet Archive". https://exoplanetarchive.ipac.caltech.edu/overview/HD%20112300%20b#planet_HD-112300-b_collapsible.
- ↑ 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.
- ↑ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
- ↑ "IAU Working Group on Star Names (WGSN)". https://www.iau.org/science/scientific_bodies/working_groups/280/.
- ↑ 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, https://archive.org/details/starnamestheirlo00alle/page/469, retrieved 2010-12-12
- ↑ (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.
- ↑ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 , Hong Kong Space Museum. Accessed online November 23, 2010.
- ↑ (in Chinese) English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name , Hong Kong Space Museum. Accessed online November 23, 2010.
- ↑ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Virgo 13 July 2019. Retrieved 2 September 2022.
- ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16
- ↑ "/ftp/cats/more/HIP/cdroms/cats". Strasbourg astronomical Data Center. https://cdsarc.cds.unistra.fr/viz-bin/ftp-index?/ftp/cats/more/HIP/cdroms/cats.
- ↑ Famaey, B. et al. (2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics 430: 165–186, doi:10.1051/0004-6361:20041272, Bibcode: 2005A&A...430..165F
- ↑ Kaler, James B., "Delta Virginis", Stars (University of Illinois), http://stars.astro.illinois.edu/sow/deltavir.html, retrieved 2012-02-07
- ↑ 23.0 23.1 Lee, Byeong-Cheol et al. (July 2023). "Long-period radial velocity variations of nine M red giants: The detection of sub-stellar companions around HD 6860 and HD 112300". Astronomy & Astrophysics.
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