1 Delphini

Star in the constellation Delphinus Delphinus constellation map.svg center 260 right Red circle.svg 10 1 Del 494 554 Location of 1 Delphini (circled) J2000 A Delphinus 20 30 17.9623 +10 53 45.335 6.200.01 B 20 30 17.9505 +10 53 46.244 8.000.01 A1:III shell (A0e + A0) −0.03 −0.11 −15.5 ± 2 −0.69 y A +19.320 +4.645 4.6400 0.0616 B 4.1851 0.1421 +19.545 +4.710 A 3.10.3 3.660.77 10,651932 1156 217 246 0.00 B 4.140.19 0.47 370 1 Delphini +10°4303 195325 101160 7836 106172 J20303+1054AB 1+Del 1 Delphini (1 Del) is the Flamsteed designation for a close binary star in the northern constellation of Delphinus. With a combined apparent magnitude of 6.08, it is barely visible to the naked eye, even under ideal conditions. Parallax measurements put the components at a distance 703 and 780 light years respectively. However, its approaching the Solar System with a radial velocity of 15 km/s. 1 Del consists of three components. The brightest of them has a magnitude of 6.1; a companion located around 0.9 arcseconds from the primary has an apparent magnitude of 8.1; and a third star, located much farther away at around 17 arcseconds from component A, is the faintest with a magnitude of around 14 and is an unrelated background object. The entire system has a stellar classification of A1: III sh, indicating that it is a white giant and a shell star. However, there is some uncertainty about the temperature class. When resolved, the secondary has a class of B9. 1 Del A has 3 times the mass of the Sun and an effective temperature of 10,651 K, giving it a bluish white glow. It is estimated to be almost 250 million years old and has a solar metallicity. Both components spin rapidly, with projected rotational velocities of 217 and 370 km/s respectively. As for the peculiarities, the shell star is a primary component; the spectrum of the secondary shows broad absorption lines. Due to the stability of the emission lines data from 1 Delphini has been used for developing models of shell stars and Be stars. References 1753792931176132608 1753792926878732672 1753792926879479936 Kharchenko N. V. Scholz R.-D. Piskunov A. E. Röser S. Schilbach E. Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ∼55000 stars and mean radial velocities of 516 Galactic open clusters and associations Astronomische Nachrichten 2007 328 9 889 10.1002/asna.200710776 0705.0878 2007AN....328..889K Fabricius C. Høg E. Makarov V. V. Mason B. D. Wycoff G. L. Urban S. E. The Tycho double star catalogue Astronomy & Astrophysics March 2002 384 1 180–189 10.1051/0004-6361:20011822 0004-6361 2002A&A...384..180F free Ralph Elmer Wilson 1953 General Catalogue of Stellar Radial Velocities Carnegie Institute Washington D.C. Publication Carnegie Institution of Washington 1953GCRV..C......0W 54001336 2016A&A...587A..22K Spectroscopy of close visual binary components of the stable shell star 1 Delphini Kubát Jiří Kubátová Brankica Doležalová Barbora Iliev Lubomir Šlechta Miroslav Astronomy and Astrophysics 2016 587 A22 10.1051/0004-6361/201526414 1601.05236 118706088 Anderson E. Francis Ch. XHIP: An extended hipparcos compilation Astronomy Letters May 2012 38 5 331–346 10.1134/S1063773712050015 en 1063-7737 2012AstL...38..331A 1108.4971 255204555 Abt Helmut A. Morrell Nidia I. The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars The Astrophysical Journal Supplement Series July 1995 99 135 10.1086/192182 0067-0049 1995ApJS...99..135A free 2002yCat.2237....0D VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system CDS/ADC Collection of Electronic Catalogues 2237 Ducati, J. R. 2002 Gontcharov G. A. Dependence of kinematics on the age of stars in the solar neighborhood Astronomy Letters December 2012 38 12 771–782 10.1134/S1063773712120031 0320-0108 2012AstL...38..771G 1606.08814 255201789 1 Anders F. Khalatyan A. Queiroz A. B. A. Chiappini C. Ardèvol J. Casamiquela L. Figueras F. Jiménez-Arranz Ó. Jordi C. Monguió M. Romero-Gómez M. Altamirano D. Antoja T. Assaad R. Cantat-Gaudin T. Castro-Ginard A. Enke H. Girardi L. Guiglion G. Khan S. Luri X. Miglio A. Minchev I. Ramos P. Santiago B. X. Steinmetz M. Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G = 18.5 Astronomy & Astrophysics February 2022 658 A91 10.1051/0004-6361/202142369 0004-6361 2022A&A...658A..91A free 2111.01860 Further reading Merrill Paul W. Burwell Cora G. Second Supplement to the Mount Wilson Catalogue and Bibliography of Stars of Classes B and a whose Spectra have Bright Hydrogen Lines. The Astrophysical Journal November 1949 110 387 0004-637X 1538-4357 10.1086/145215 1949ApJ...110..387M free Merrill Paul W. Spectra of Two Stars with Stable Shells The Astrophysical Journal January 1952 115 42 0004-637X 1538-4357 10.1086/145507 1952ApJ...115...42M free van den Bos W. H. Micrometer measures of double stars. The Astronomical Journal February 1958 63 63 0004-6256 10.1086/107694 1958AJ.....63...63V free Ringuelet-Kaswalder Adela E. Shell Stars and Rotationally Unstable Be Stars Publications of the Astronomical Society of the Pacific August 1963 75 445 323 0004-6280 1538-3873 10.1086/127960 1963PASP...75..323R free Gray David F. Marlborough J. M. Photoelectric Profile Measurements of Halpha and Hbeta in be Stars The Astrophysical Journal Supplement Series March 1974 27 121 0067-0049 1538-4365 10.1086/190291 1974ApJS...27..121G free Delphini, 01 Category:Delphinus Category:Triple stars 101160 7836 195325 Category:Durchmusterung objects Category:Shell stars Category:A-type giants Category:Emission-line stars Category:Population I stars Category:A0 stars