Star in the constellation Aquila
21 Aquilae is a solitary[ 14] variable star in the equatorial constellation of Aquila . It has the variable star designation V1288 Aql ; 21 Aquilae is its Flamsteed designation . This object is visible to the naked eye as a dim, blue-white hued star with a baseline apparent visual magnitude of about 5.1. The star is located at a distance of around 680 light-years (210 parsecs ) from Earth, give or take a 20 light-year margin of error . It is moving closer to the Earth with a heliocentric radial velocity of –5 km/s.[ 6]
In 1962, Helmut A. Abt and John C. Gloson published data showing that 21 Aquilae was a variable star.[ 15] Based on that publication, the star was given its variable star designation in 1972.[ 16]
The stellar classification of this star is B8 II-III, with the luminosity class of II-III suggesting that the spectrum displays elements of both a giant star and a bright giant . It is a chemically peculiar star of the Mercury-Manganese type (CP3),[ 10] although some catalogues consider that status to be doubtful.[ 17] This is a probable Alpha2 Canum Venaticorum variable that ranges in visual magnitude from 5.06 down to 5.16.[ 3] The star is radiating 704 times the luminosity of the Sun from its photosphere at an effective temperature of 12,014 K ; this gives it the blue-white glow of a B-type star .[ 18]
21 Aquilae is catalogued as an optical double star, having a 12th magnitude companion 37″ away as of 2010. It was first identified as a double star by John Herschel .[ 19] The companion is a distant background object.[ 20]
References
^ Veto, B. (May 1980). "Ultraviolet Observations of the Silicon Star HD 179761". Information Bulletin on Variable Stars . 1778 (1): 1. Bibcode :1980IBVS.1778....1V .
^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties" . Astronomy and Astrophysics . 674 : A1. arXiv :2208.00211 . Bibcode :2023A&A...674A...1G . doi :10.1051/0004-6361/202243940 . S2CID 244398875 .
Gaia DR3 record for this source at VizieR .
^ a b c Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports . 5.1. 61 (1): 80–88. Bibcode :2017ARep...61...80S . doi :10.1134/S1063772917010085 . S2CID 125853869 .
^ Cowley, A. (November 1972). "Spectral classification of the bright B8 stars". Astronomical Journal . 77 : 750–755. Bibcode :1972AJ.....77..750C . doi :10.1086/111348 .
^ a b Stepien, K. (December 1968). "Photometric behavior of magnetic stars". Astrophysical Journal . 154 : 945. Bibcode :1968ApJ...154..945S . doi :10.1086/149815 .
^ a b Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Batten, Alan Henry; Heard, John Frederick (eds.). Proceedings from IAU Symposium no. 30 . Determination of Radial Velocities and Their Applications . Vol. 30. University of Toronto: International Astronomical Union . p. 57. Bibcode :1967IAUS...30...57E .
^ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters . 38 (5): 331. arXiv :1108.4971 . Bibcode :2012AstL...38..331A . doi :10.1134/S1063773712050015 . S2CID 119257644 .
^ a b c d Fouesneau, M.; Andrae, R.; Dharmawardena, T.; Rybizki, J.; Bailer-Jones, C. A. L.; Demleitner, M. (2022). "Astrophysical parameters from Gaia DR2, 2MASS, and AllWISE". Astronomy and Astrophysics . 662 : A125. arXiv :2201.03252 . Bibcode :2022A&A...662A.125F . doi :10.1051/0004-6361/202141828 . S2CID 245837778 .
^ Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (20 December 2021). "Stellar and substellar companions from Gaia EDR3" . Astronomy & Astrophysics . 657 : A7. arXiv :2109.10912 . Bibcode :2022A&A...657A...7K . doi :10.1051/0004-6361/202142146 . eISSN 1432-0746 . ISSN 0004-6361 .
^ a b c Ghazaryan, S.; et al. (November 2018). "New catalogue of chemically peculiar stars, and statistical analysis" . Monthly Notices of the Royal Astronomical Society . 480 (3): 2953–2962. arXiv :1807.06902 . Bibcode :2018MNRAS.480.2953G . doi :10.1093/mnras/sty1912 . S2CID 119062018 .
^ Oelkers, Ryan J.; Rodriguez, Joseph E.; Stassun, Keivan G.; Pepper, Joshua; Somers, Garrett; Kafka, Stella; Stevens, Daniel J.; Beatty, Thomas G.; Siverd, Robert J.; Lund, Michael B.; Kuhn, Rudolf B.; James, David; Gaudi, B. Scott (2018). "Variability Properties of Four Million Sources in the TESS Input Catalog Observed with the Kilodegree Extremely Little Telescope Survey" . The Astronomical Journal . 155 (1): 39. arXiv :1711.03608 . Bibcode :2018AJ....155...39O . doi :10.3847/1538-3881/aa9bf4 . S2CID 119515775 .
^ Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters . 38 (12): 771–782. arXiv :1606.08814 . Bibcode :2012AstL...38..771G . doi :10.1134/S1063773712120031 . ISSN 0320-0108 . S2CID 118345778 .
^ "21 Aql" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-06-05 .
^ Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems" . Monthly Notices of the Royal Astronomical Society . 389 (2): 869. arXiv :0806.2878 . Bibcode :2008MNRAS.389..869E . doi :10.1111/j.1365-2966.2008.13596.x . S2CID 14878976 .
^ Abt, Helmut A.; Golson, John C. (July 1962). "Colors and Variability of Magnetic Stars" . Astrophysical Journal . 136 : 35–51. Bibcode :1962ApJ...136...35A . doi :10.1086/147349 . Retrieved 21 November 2024 .
^ Kukarkin, B. V.; Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (September 1972). "58th Name-List of Variable Stars" (PDF) . Information Bulletin on Variable Stars . 717 . Bibcode :1972IBVS..717....1K . Retrieved 21 November 2024 .
^ Renson, P.; Manfroid, J. (May 2009). "Catalogue of Ap, HgMn and Am stars" . Astronomy and Astrophysics . 498 (3): 961–966. Bibcode :2009A&A...498..961R . doi :10.1051/0004-6361/200810788 .
^ "The Colour of Stars" . Australia Telescope, Outreach and Education . Commonwealth Scientific and Industrial Research Organisation . December 21, 2004. Archived from the original on March 18, 2012. Retrieved 2012-01-16 .
^ Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog" . The Astronomical Journal . 122 (6): 3466–3471. Bibcode :2001AJ....122.3466M . doi :10.1086/323920 . Retrieved 2015-07-22 .
^ Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties" . Astronomy and Astrophysics . 674 : A1. arXiv :2208.00211 . Bibcode :2023A&A...674A...1G . doi :10.1051/0004-6361/202243940 . S2CID 244398875 .
Gaia DR3 record for this source at VizieR .
External links