Astronomy:15 Andromedae
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 23h 34m 37.53652s[1] |
| Declination | +40° 14′ 11.1795″[1] |
| Apparent magnitude (V) | 5.55[2] |
| Characteristics | |
| Spectral type | A1 III,[3] A1 Va,[4] or kA1hA3mA0.5 Va+[5] |
| B−V color index | 0.096±0.005[2] |
| Variable type | δ Sct[6] |
| Astrometry | |
| Radial velocity (Rv) | 13.1±0.6[2] km/s |
| Proper motion (μ) | RA: -18.165 mas/yr Dec.: −46.183[1] mas/yr |
| Parallax (π) | 12.9406 ± 0.0973[1] mas |
| Distance | 252 ± 2 ly (77.3 ± 0.6 pc) |
| Absolute magnitude (MV) | +1.16±0.16[7] |
| Details[3] | |
| Mass | 2.7 M☉ |
| Luminosity | 27 L☉ |
| Surface gravity (log g) | 3.90±0.03[7] cgs |
| Temperature | 9,225 K |
| Rotational velocity (v sin i) | 105[7] km/s |
| Age | 130 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |

15 Andromedae, abbreviated 15 And, is a single,[10] variable star[6] in the northern constellation of Andromeda. 15 Andromedae is the Flamsteed designation, while its variable star designation is V340 And.[8] Its apparent visual magnitude is 5.55,[2] which indicates it is faintly visible to the naked eye. Its estimated distance from the Earth is 252 light years, and it is moving further away with a heliocentric radial velocity of 13 km/s.[2]
Rufener and Bartholdi (1982) included the star (under the name HD 221756) in their list of 333 variable, microvariable and suspected variable stars, based on multicolor photometry performed at several observatories in the 1960s and 1970s. However they were unable to conclusively demonstrate that the star's brightness varied.[11] Proof of variability, along with a light curve and period estimate of 63 minutes, was published by Paunzen and Handler in 1996.[12] The star was given its variable star designation, V340 Andromedae, in 1997.[13]
Depending on the source, this star has been classified as a giant star with a stellar classification of A1 III,[3] an A-type main-sequence star with a class of A1 Va,[4] or a Lambda Boötis star with a class of kA1hA3mA0.5 Va+.[5] It is a Delta Scuti variable that changes in brightness by 0.03 magnitude.[6] Two variability cycles, with periods 0.0403 and 0.0449 days, have been observed, a common feature for Lambda Boötis stars.[14] The star is around 130[3] million years old and has a high rotation rate, showing a projected rotational velocity of 105 km/s.[7] It has 2.7 times the mass of the Sun and is radiating 27 times the Sun's luminosity from its photosphere at an effective temperature of 9,225 K.[3]
This system has an excess emission of infrared radiation that suggests the presence of an orbiting disk of dust at a distance of around 50 AU from the host star.[3]
References
- ↑ 1.0 1.1 1.2 1.3 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.
- ↑ 2.0 2.1 2.2 2.3 2.4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Wyatt, M. C. et al. (July 2007), "Steady State Evolution of Debris Disks around A Stars", The Astrophysical Journal 663 (1): 365–382, doi:10.1086/518404, Bibcode: 2007ApJ...663..365W
- ↑ 4.0 4.1 Paunzen, E. et al. (July 2001), "A spectroscopic survey for λ Bootis stars. II. The observational data", Astronomy and Astrophysics 373 (2): 625–632, doi:10.1051/0004-6361:20010630, Bibcode: 2001A&A...373..625P.
- ↑ 5.0 5.1 Murphy, Simon J. et al. (2015), "An Evaluation of the Membership Probability of 212 λ Boo Stars. I. A Catalogue" (in en), Publications of the Astronomical Society of Australia 32: e036, doi:10.1017/pasa.2015.34, ISSN 1323-3580, Bibcode: 2015PASA...32...36M.
- ↑ 6.0 6.1 6.2 Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2017), "General catalogue of variable stars: Version GCVS 5.1", Astronomy Reports 61 (1): 80, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S.
- ↑ 7.0 7.1 7.2 7.3 Paunzen, E. et al. (November 2002), "The status of Galactic field λ Bootis stars in the post-Hipparcos era", Monthly Notices of the Royal Astronomical Society 336 (3): 1030–1042, doi:10.1046/j.1365-8711.2002.05865.x, Bibcode: 2002MNRAS.336.1030P.
- ↑ 8.0 8.1 "15 And". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=15+And.
- ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Rufener, F.; Bartholdi, P. (June 1982). "List of 333 variable microvariable or suspected variable stars detected in the Geneva photometry". Astronomy and Astrophysics, Supplement Series 48: 503–511. Bibcode: 1982A&AS...48..503R. https://articles.adsabs.harvard.edu/pdf/1982A%26AS...48..503R. Retrieved 5 November 2024.
- ↑ Paunzen, E.; Handler, G. (March 1996). "Pulsation of HD 83041 and HD 221756". Information Bulletin on Variable Stars 4301: 1. Bibcode: 1996IBVS.4301....1P. https://articles.adsabs.harvard.edu/pdf/1996IBVS.4301....1P. Retrieved 5 November 2024.
- ↑ Kazarovets, E. V.; Samus, N. N. (April 1997). "The 73rd Name-List of Variable Stars". Information Bulletin on Variable Stars 4471: 1–45. Bibcode: 1997IBVS.4471....1K. https://ibvs.konkoly.hu/pub/ibvs/4401/4471.pdf. Retrieved 5 November 2024.
- ↑ Dorokhova, T. N. et al. (March 2008), "The pulsating λ Bootis star 15 Andromedae: results from a three-site photometry campaign.", Astronomy and Astrophysics 480 (1): 187–191, doi:10.1051/0004-6361:20078750, Bibcode: 2008A&A...480..187D.
External links
Coordinates:
23h 34m 37.5s, 40° 14′ 11″
