Star in the constellation Vulpecula
30 Vulpeculae is a binary star system in the northern constellation of Vulpecula , located mid-way between Epsilon Cygni and a diamond-shaped asterism in Delphinus . It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4.91.[ 2] The system is located approximately 350 light years away from the Sun based on parallax ,[ 1] and is drifting further away with a mean radial velocity of +30 km/s.[ 4] The system has a relatively high proper motion , traversing the celestial sphere at the rate of 0.186 arc seconds per annum.[ 11]
The variable radial velocity of this system was announced in 1922 by W. W. Campbell . It is a single-lined spectroscopic binary system with an orbital period of 6.86 years and an eccentricity of 0.38. The a sin i value is 149 ± 4 Gm (1.00 ± 0.03 AU ), where a is the semimajor axis and i is the orbital inclination . This provides a lower bound on the true semimajor axis.[ 6]
The visible component is an aging giant star with a stellar classification of K1 III[ 3] and an estimated age of 4.20[ 7] billion years old. Having exhausted the supply of hydrogen at its core , the star has expanded to 22[ 1] times the Sun's radius . It has 1.55[ 7] times the mass of the Sun and is radiating 173[ 1] times the Sun's luminosity from its swollen photosphere at an effective temperature of 4,498 K.[ 1]
References
^ a b c d e f g h i j k l Brown, A. G. A. ; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties" . Astronomy & Astrophysics . 616 . A1. arXiv :1804.09365 . Bibcode :2018A&A...616A...1G . doi :10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR .
^ a b c d Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues . 2237 . Bibcode :2002yCat.2237....0D .
^ a b Keenan, P. C.; McNeil, R. C. (1989). "The Perkins catalog of revised MK types for the cooler stars". The Astrophysical Journal Supplement Series . 71 : 245. Bibcode :1989ApJS...71..245K . doi :10.1086/191373 .
^ a b Famaey, B.; et al. (2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data". Astronomy & Astrophysics . 430 : 165–186. arXiv :astro-ph/0409579 . Bibcode :2005A&A...430..165F . doi :10.1051/0004-6361:20041272 . S2CID 17804304 .
^ a b 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 . Vizier catalog entry
^ a b Griffin, R. F. (August 1983). "Spectroscopic binary orbits from photoelectric radial velocities. Paper 51: 30 Vulpeculae". The Observatory . 103 : 199–203. Bibcode :1983Obs...103..199G .
^ a b c d Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". Astronomical Journal . 150 (3). 88. arXiv :1507.01466 . Bibcode :2015AJ....150...88L . doi :10.1088/0004-6256/150/3/88 . S2CID 118505114 .
^ McWilliam, Andrew (December 1990). "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances" . Astrophysical Journal Supplement Series . 74 : 1075–1128. Bibcode :1990ApJS...74.1075M . doi :10.1086/191527 .
^ De Medeiros, J. R.; et al. (October 2002). "The Rotation of Binary Systems with Evolved Components". The Astrophysical Journal . 578 (2): 943–950. arXiv :astro-ph/0207288 . Bibcode :2002ApJ...578..943D . doi :10.1086/342613 . S2CID 16196039 .
^ "30 Vul" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2019-06-27 .
^ Lépine, Sébastien; Shara, Michael M. (March 2005). "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)". The Astronomical Journal . 129 (3): 1483–1522. arXiv :astro-ph/0412070 . Bibcode :2005AJ....129.1483L . doi :10.1086/427854 . S2CID 2603568 .