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Star in the constellation Serpens
τ7 Serpentis
Observation dataEpoch J2000.0 Equinox J2000.0 (ICRS )
Constellation
Serpens [ 1]
Right ascension 15h 41m 54.7166s [ 2]
Declination
+18° 27′ 50.531″[ 2]
Apparent magnitude (V)5.8[ 3]
Characteristics
Evolutionary stage
main sequence [ 2]
Spectral type
A8Vam[ 4]
U−B color index
+0.11[ 5]
B−V color index
+0.20[ 5]
R−I color index
+0.10[ 5]
Astrometry Radial velocity (Rv )± 0.12[ 2] km/s Proper motion (μ) RA: −61.654[ 2] mas /yr Dec.: +54.319[ 2] mas /yr Parallax (π)18.7185± 0.0408 mas [ 2] Distance 174.2 ± 0.4 ly pc ) Absolute magnitude (MV )+2.18[ 1] Details Mass 1.8[ 6] M ☉ Radius 1.8[ 6] R ☉ Luminosity 11[ 6] L ☉ Surface gravity (log g )4.20[ 6] cgs Temperature 7,809[ 6] K Metallicity [Fe/H] −0.02[ 7] dex Rotational velocity (v sin i )78[ 8] Age 839[ 7] Myr Other designations τ7 Ser , 22 Serpentis , BD +18°3059GC 21111HD 140232HIP 76878HR 5845SAO 101686PPM 131613WDS J15419+1828AB[ 9] Database references SIMBAD data
Tau7 Serpentis , Latinized from τ7 Serpentis , is an A-type star in the constellation of Serpens , 174 light-years from the Earth . It has an apparent visual magnitude of approximately 5.804. It is a well-known Am star , a type of chemically peculiar star with unusually strong lines of heavier elements (metals) due to slow rotation and stratification of elements in the star's atmosphere.[ 10]
^ 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 . ^ a b c d e f g 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 .^ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics . 355 . Bibcode :2000A&A...355L..27H . ^ Barry, Don C. (1970). "Spectral Classification of a and F Stars". Astrophysical Journal Supplement . 19 : 281. Bibcode :1970ApJS...19..281B . doi :10.1086/190209 . ^ a b c HR 5845 , database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50 . Accessed on line September 19, 2008.^ a b c d e Stassun, Keivan G.; et al. (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 ^ a b Gontcharov, G. A. (2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters . 38 (12): 771. arXiv :1606.08814 Bibcode :2012AstL...38..771G . doi :10.1134/S1063773712120031 . ^ Schröder, C.; Schmitt, J. H. M. M. (2007). "X-ray emission from A-type stars". Astronomy and Astrophysics . 475 (2): 677. Bibcode :2007A&A...475..677S . doi :10.1051/0004-6361:20077429 . ^ * 22 Ser -- Star , database entry, SIMBAD . Accessed on line September 19, 2008.^ Renson, P.; Manfroid, J. (2009). "Catalogue of Ap, HGMN and Am stars". Astronomy and Astrophysics . 498 (3): 961. Bibcode :2009A&A...498..961R . doi :10.1051/0004-6361/200810788 .
