15 Andromedae

Star in the constellation Andromeda Andromeda constellation map.svg center 260 right Red circle.svg 10 15 Andromedae 946 386 Location of 15 Andromedae (circled) J2000.0 Andromeda 23 34 37.53683 +40 14 11.1827 5.55 A1 III, A1 Va, or kA1hA3mA0.5 Va+ 0.096 0.005 δ Sct 13.1 0.6 −18.402 0.060 −46.401 0.038 13.0457 0.0476 +1.16 0.16 2.7 27 9,225 3.90 0.03 105 130 V340 And 15 And +39°5114 221756 116354 8947 73346 64401 1616 15+And thumb|left|A light curve for V340 Andromedae, plotted from TESS data 15 Andromedae, abbreviated 15 And, is a single, variable star in the northern constellation of Andromeda. 15 Andromedae is the Flamsteed designation, while its variable star designation is V340 And. Its apparent visual magnitude is 5.55, which indicates it is faintly visible to the naked eye. Its estimated distance from the Earth is 250 light years, and it is moving further away with a heliocentric radial velocity of 13 km/s. 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. Proof of variability, along with a light curve and period estimate of 63 minutes, was published by Paunzen and Handler in 1996. The star was given its variable star designation, V340 Andromedae, in 1997. Depending on the source, this star has been classified as a giant star with a stellar classification of A1 III, an A-type main-sequence star with a class of A1 Va, or a Lambda Boötis star with a class of kA1hA3mA0.5 Va+. It is a Delta Scuti variable that changes in brightness by 0.03 magnitude. Two variability cycles, with periods 0.0403 and 0.0449 days, have been observed, a common feature for Lambda Boötis stars. The star is around 130 million years old and has a high rotation rate, showing a projected rotational velocity of 105 km/s. 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. 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. References 15 And September 20, 2018 1920585924529574144 MAST: Barbara A. Mikulski Archive for Space Telescopes https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html Space Telescope Science Institute 8 December 2021 Eggleton P. P. Tokovinin A. A. A catalogue of multiplicity among bright stellar systems Monthly Notices of the Royal Astronomical Society 389 2 869–879 September 2008 10.1111/j.1365-2966.2008.13596.x free 2008MNRAS.389..869E 0806.2878 14878976 . Kazarovets E. V. Samus N. N. The 73rd Name-List of Variable Stars Information Bulletin on Variable Stars April 1997 4471 1–45 1997IBVS.4471....1K https://ibvs.konkoly.hu/pub/ibvs/4401/4471.pdf 5 November 2024 Paunzen E. Handler G. Pulsation of HD 83041 and HD 221756 Information Bulletin on Variable Stars March 1996 4301 1 1996IBVS.4301....1P https://articles.adsabs.harvard.edu/pdf/1996IBVS.4301....1P 5 November 2024 Rufener F. Bartholdi P. List of 333 variable microvariable or suspected variable stars detected in the Geneva photometry Astronomy and Astrophysics, Supplement Series June 1982 48 503–511 1982A&AS...48..503R https://articles.adsabs.harvard.edu/pdf/1982A%26AS...48..503R 5 November 2024 1 Wyatt M. C. Smith R. Su K. Y. L. Rieke G. H. Greaves J. S. Beichman C. A. Bryden G. Steady State Evolution of Debris Disks around A Stars The Astrophysical Journal July 2007 663 1 365–382 10.1086/518404 2007ApJ...663..365W astro-ph/0703608 18883195 1 The status of Galactic field λ Bootis stars in the post-Hipparcos era Paunzen E. Iliev I. Kh. Kamp I. Barzova I. S. Monthly Notices of the Royal Astronomical Society 336 3 1030–1042 November 2002 10.1046/j.1365-8711.2002.05865.x free 2002MNRAS.336.1030P astro-ph/0207488 2389489 . 1 Paunzen E. Duffee B. Heiter U. Kuschnig R. Weiss W. W. A spectroscopic survey for λ Bootis stars. II. The observational data Astronomy and Astrophysics . 373 625–632 July 2001 2 10.1051/0004-6361:20010630 2001A&A...373..625P free XHIP: An extended hipparcos compilation Anderson E. Francis Ch. Astronomy Letters 1108.4971 38 5 331 2012 2012AstL...38..331A 10.1134/S1063773712050015 119257644 . General catalogue of variable stars: Version GCVS 5.1 Samus' N. N. Kazarovets E. V. Durlevich O. V. Kireeva N. N. Pastukhova E. N. Astronomy Reports 61 1 80 2017 . 10.1134/S1063772917010085 2017ARep...61...80S 125853869 1 Murphy Simon J. Corbally Christopher J. Gray Richard O. Cheng Kwang-Ping Neff James E. Koen Chris Kuehn Charles A. Newsome Ian Riggs Quinlin An Evaluation of the Membership Probability of 212 λ Boo Stars. I. A Catalogue Publications of the Astronomical Society of Australia 2015 en 32 e036 . 10.1017/pasa.2015.34 1323-3580 1508.03633 2015PASA...32...36M 59405545 1 Dorokhova T. N. Handler G. Dorokhov N. I. Rodriguez E. Udovichenko S. N. The pulsating λ Bootis star 15 Andromedae: results from a three-site photometry campaign. Astronomy and Astrophysics March 2008 480 1 187–191 . 10.1051/0004-6361:20078750 2008A&A...480..187D free External links Image 15 Andromedae 23 34 37.5 40 14 11 233 Category:A-type giants Category:A-type main-sequence stars Category:Delta Scuti variables Category:Lambda Boötis stars Category:Andromeda (constellation) Category:Durchmusterung objects Andromedae, 15 221756 116354 8947 Andromedae, V340 Category:A1 stars