Star in the constellation Lacerta
9 Lacertae is a single[ 9] star in the northern constellation Lacerta , located 172 light years away from Sun.[ 1] It is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of 4.64.[ 2] This object is moving further from the Earth with a heliocentric radial velocity of +10 km/s.[ 2]
This is an A-type main-sequence star with a stellar classification of A9VkA7mA6.[ 3] This notation indicates it has the Hydrogen lines of an A9 star, the Calcium K line of an A7 star, and the metal lines of an A6. It is 513[ 4] million years old with a high projected rotational velocity of 105 km/s.[ 6] The star has 1.59[ 4] times the mass of the Sun and about 2.1[ 5] times the Sun's radius . It is radiating 34.6[ 6] times the Sun's luminosity from its photosphere at an effective temperature of 7,614 K.[ 4]
References
^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics , 474 (2): 653– 664, arXiv :0708.1752 , Bibcode :2007A&A...474..653V , doi :10.1051/0004-6361:20078357 , S2CID 18759600 .
^ a b c d e f 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 Gray, R. O.; et al. (2001), "The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. I. Precise Spectral Types for 372 Stars", The Astronomical Journal , 121 (4): 2148, Bibcode :2001AJ....121.2148G , doi :10.1086/319956 .
^ a b c d e f g David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal , 804 (2): 146, arXiv :1501.03154 , Bibcode :2015ApJ...804..146D , doi :10.1088/0004-637X/804/2/146 , S2CID 33401607 .
^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics , 367 (Third ed.): 521– 524, arXiv :astro-ph/0012289 , Bibcode :2001A&A...367..521P , doi :10.1051/0004-6361:20000451 , S2CID 425754 .
^ a b c d Zorec, J.; et al. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy and Astrophysics , 537 : A120, arXiv :1201.2052 , Bibcode :2012A&A...537A.120Z , doi :10.1051/0004-6361/201117691 , S2CID 55586789 .
^ Erspamer, D.; North, P. (February 2003), "Automated spectroscopic abundances of A and F-type stars using echelle spectrographs. II. Abundances of 140 A-F stars from ELODIE", Astronomy and Astrophysics , 398 (3): 1121– 1135, arXiv :astro-ph/0210065 , Bibcode :2003A&A...398.1121E , doi :10.1051/0004-6361:20021711 , S2CID 1109164 .
^ "9 Lac" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-01-31 .
^ 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– 879, arXiv :0806.2878 , Bibcode :2008MNRAS.389..869E , doi :10.1111/j.1365-2966.2008.13596.x , S2CID 14878976 .