Astronomy:15 Andromedae

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Short description: Star in the constellation Andromeda
15 Andromedae
V340AndLightCurve.png
A light curve for V340 Andromedae, plotted from TESS data[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Andromeda
Right ascension  23h 34m 37.53652s[2]
Declination +40° 14′ 11.1795″[2]
Apparent magnitude (V) 5.55[3]
Characteristics
Spectral type A1 III,[4] A1 Va,[5] or kA1hA3mA0.5 Va+.[6]
U−B color index 0.08
B−V color index 0.096±0.005[3]
Variable type δ Sct[7]
Astrometry
Radial velocity (Rv)13.1±0.6[3] km/s
Proper motion (μ) RA: -18.165 mas/yr
Dec.: −46.183[2] mas/yr
Parallax (π)12.9406 ± 0.0973[2] mas
Distance252 ± 2 ly
(77.3 ± 0.6 pc)
Absolute magnitude (MV)+1.16±0.16[8]
Details[4]
Mass2.7 M
Luminosity27 L
Surface gravity (log g)3.90±0.03[8] cgs
Temperature9,225 K
Rotational velocity (v sin i)105[8] km/s
Age130 Myr
Other designations
15 And, V340 And, BD+39° 5114, FK5 1616, HD 221756, HIP 116354, HR 8947, SAO 73346, PPM 64401[9]
Database references
SIMBADdata

15 Andromedae, abbreviated 15 And, is a single,[10] variable star[7] in the northern constellation of Andromeda. 15 Andromedae is the Flamsteed designation, while its variable star designation is V340 And.[9] Its apparent visual magnitude is 5.55,[3] 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.[3]

Depending on the source, this star has been classified as a giant star with a stellar classification of A1 III,[4] an A-type main-sequence star with a class of A1 Va,[5] or a Lambda Boötis star with a class of kA1hA3mA0.5 Va+.[6] It is a Delta Scuti variable that changes in brightness by 0.03 magnitude.[7] Two variability cycles, with periods 0.0403 and 0.0449 days, have been observed, a common feature for Lambda Boötis stars.[11] The star is around 130[4] million years old and has a high rotation rate, showing a projected rotational velocity of 105 km/s.[8] 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.[4]

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.[4]

References

  1. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html. 
  2. 2.0 2.1 2.2 2.3 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. Bibcode2018A&A...616A...1G. 
  3. 3.0 3.1 3.2 3.3 3.4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 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, Bibcode2007ApJ...663..365W 
  5. 5.0 5.1 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, Bibcode2001A&A...373..625P. 
  6. 6.0 6.1 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, Bibcode2015PASA...32...36M. 
  7. 7.0 7.1 7.2 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, Bibcode2017ARep...61...80S. 
  8. 8.0 8.1 8.2 8.3 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, Bibcode2002MNRAS.336.1030P. 
  9. 9.0 9.1 "15 And". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=15+And. 
  10. 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, Bibcode2008MNRAS.389..869E. 
  11. 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, Bibcode2008A&A...480..187D. 

External links

Coordinates: Sky map 23h 34m 37.5s, 40° 14′ 11″