A-type dwarf; Camelopardalis
HD 27322 , also known as HR 1342 , is a binary star located in the northern circumpolar constellation Camelopardalis . The visible component is faintly visible to the naked eye as a white-hued point of light with an apparent magnitude of 5.92.[ 2] The object is located relatively close at a distance of 313 light-years based on Gaia DR3 parallax measurements,[ 1] and it is drifting closer with a heliocentric radial velocity of approximately −13 km/s .[ 7] At its current distance, HD 27322's brightness is diminished by 0.24 magnitudes due to interstellar extinction [ 14] and it has an absolute magnitude of +0.98.[ 8]
HD 27322 A has a stellar classification of A3 V,[ 4] indicating that it is an ordinary A-type main-sequence star that is generating energy via hydrogen fusion at its core . Abt & Morell (1995) gave a hotter and slightly more evolved classification of A2 IV-V,[ 5] indicating that it is an A-type star with a luminosity class intermediate between a main sequence star and a subgiant . At the age of 640 million years ,[ 11] HD 27322 A has completed 79.5% of its main sequence lifetime.[ 3] It has 1.9 times the mass of the Sun [ 9] and 2.64 times the radius of the Sun .[ 10] It radiates 54.7 times the luminosity of the Sun [ 1] from its photosphere at an effective temperature of 8,414 K .[ 3] HD 27322 A is metal deficient with an iron abundance 56% that of the Sun 's ([Fe/H] = −0.25)[ 12] and it spins rapidly with a projected rotational velocity of 130 km/s .[ 5]
The object was generally classified as a solitary star .[ 15] However, evidence of HD 27322 being a binary first arose when an X-ray emission with a luminosity of 3.22× 1020 W was detected around the star.[ 16] A-type stars are expected to be X-ray quiet, so it might be coming from a hidden companion. A 2016 spectroscopic survey detected a companion around HD 27322.[ 9] It has 1.3 times the mass of the Sun and it has an effective temperature of 6,492 K.[ 9] HD 27322 B is metal deficient with a [Fe/H] of −0.5 and it spins modestly with a projected rotational velocity of 20 km/s.[ 9]
References
^ a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties" . Astronomy and Astrophysics . 674 : A1. arXiv :2208.00211 . Bibcode :2023A&A...674A...1G . doi :10.1051/0004-6361/202243940 . S2CID 244398875 .
Gaia DR3 record for this source at VizieR .
^ a b Oja, T. (August 1991). "UBV photometry of stars whose positions are accurately known. VI". Astronomy and Astrophysics Supplement Series . 89 : 415. Bibcode :1991A&AS...89..415O . ISSN 0365-0138 .
^ a b c d Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars IV: Evolution of rotational velocities" . Astronomy & Astrophysics . 537 : A120. arXiv :1201.2052 . Bibcode :2012A&A...537A.120Z . doi :10.1051/0004-6361/201117691 . eISSN 1432-0746 . ISSN 0004-6361 . S2CID 55586789 .
^ a b Cowley, A.; Cowley, C.; Jaschek, M.; Jaschek, C. (April 1969). "A study of the bright stars. I. A catalogue of spectral classifications". The Astronomical Journal . 74 : 375. Bibcode :1969AJ.....74..375C . doi :10.1086/110819 . ISSN 0004-6256 . S2CID 121555804 .
^ a b c d Abt, Helmut A.; Morrell, Nidia I. (July 1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars" . The Astrophysical Journal Supplement Series . 99 : 135. Bibcode :1995ApJS...99..135A . doi :10.1086/192182 . ISSN 0067-0049 . S2CID 120495962 .
^ a b Guetter, H. H.; Hewitt, A. V. (1984). "Photoelectric UBV photometry for 317 PZT and VZT stars" . Publications of the Astronomical Society of the Pacific . 96 . IOP Publishing: 441. Bibcode :1984PASP...96..441G . doi :10.1086/131362 . ISSN 0004-6280 . S2CID 122222245 .
^ a b Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system". Astronomy Letters . 32 (11): 759– 771. arXiv :1606.08053 . Bibcode :2006AstL...32..759G . doi :10.1134/S1063773706110065 . eISSN 1562-6873 . ISSN 1063-7737 . S2CID 119231169 .
^ a b Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters . 38 (5): 331– 346. arXiv :1108.4971 . Bibcode :2012AstL...38..331A . doi :10.1134/S1063773712050015 . eISSN 1562-6873 . ISSN 1063-7737 . S2CID 119257644 .
^ a b c d e f g h i Gullikson, Kevin; Kraus, Adam; Dodson-Robinson, Sarah (25 July 2016). "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars" . The Astronomical Journal . 152 (2): 40. arXiv :1604.06456 . Bibcode :2016AJ....152...40G . doi :10.3847/0004-6256/152/2/40 . eISSN 1538-3881 . S2CID 119179065 .
^ a b Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List" . The Astronomical Journal . 158 (4): 138. arXiv :1905.10694 . Bibcode :2019AJ....158..138S . doi :10.3847/1538-3881/ab3467 . eISSN 1538-3881 . hdl :1721.1/124721 . S2CID 166227927 .
^ a b c David, Trevor J.; Hillenbrand, Lynne A. (12 May 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 . eISSN 1538-4357 . S2CID 33401607 .
^ a b Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18" . Astronomy & Astrophysics . 628 : A94. arXiv :1904.11302 . Bibcode :2019A&A...628A..94A . doi :10.1051/0004-6361/201935765 . eISSN 1432-0746 . ISSN 0004-6361 . S2CID 131780028 .
^ "HD 27322" . SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved July 17, 2023 .
^ Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars" . Monthly Notices of the Royal Astronomical Society . 472 (4): 3805– 3820. arXiv :1709.01160 . Bibcode :2017MNRAS.472.3805G . doi :10.1093/mnras/stx2219 . eISSN 1365-2966 . ISSN 0035-8711 . S2CID 118879856 .
^ Eggleton, P. P.; Tokovinin, A. A. (11 September 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 . eISSN 1365-2966 . ISSN 0035-8711 . S2CID 14878976 .
^ Schröder, C.; Schmitt, J. H. M. M. (24 September 2007). "X-ray emission from A-type stars" . Astronomy & Astrophysics . 475 (2): 677– 684. Bibcode :2007A&A...475..677S . doi :10.1051/0004-6361:20077429 . eISSN 1432-0746 . ISSN 0004-6361 . S2CID 120317590 .