10 Serpentis

10 Serpentis
Observation data
Epoch J2000      Equinox J2000
Constellation Serpens
Right ascension  15h 28m 38.23670s[1]
Declination +01° 50′ 31.4852″[1]
Apparent magnitude (V) 5.15[2]
Spectral type A6 III[3] or A7 IV[4]
B−V color index 0.245±0.005[2]
Radial velocity (Rv)−10.2±2.8[2] km/s
Proper motion (μ) RA: −85.35[1] mas/yr
Dec.: −34.31[1] mas/yr
Parallax (π)25.16 ± 0.31[1] mas
Distance130 ± 2 ly
(39.7 ± 0.5 pc)
Absolute magnitude (MV)2.15[2]
Mass1.64[5] M
Luminosity11.9±0.4[6] L
Surface gravity (log g)4.24±0.14[5] cgs
Temperature7,872±268[5] K
Rotational velocity (v sin i)110[6] km/s
Age424[5] Myr
Other designations
10 Ser, BD+02° 2965, FK5 3221, HD 137898, HIP 75761, HR 5746, SAO 121020[7]
Database references

10 Serpentis is a single,[8] white-hued star in Serpens Caput, the western section of the equatorial constellation of Serpens. It is faintly visible to the naked eye with an apparent visual magnitude of 5.15.[2] Located around 129 ly (39.7 pc) distant, it is moving closer to the Sun with a heliocentric radial velocity of −10 km/s and will make its closest approach in around 983,000 years at a separation of about 112 ly (34.2 pc).[2]

Abt and Morrell (1995) gave this star a stellar classification of A6 III,[3] matching an evolved red giant star that has used up its core hydrogen. In contrast, Houk and Swift (1999) classed it A7 IV,[4] which is more in line with an evolving subgiant star that is on its way to becoming a giant. It has a high rate of spin with a projected rotational velocity of 115 km/s, giving it an oblate shape with an equatorial bulge that is an estimated 7% larger than the polar radius.[9] The star is about 424 million years old with 1.64[5] times the mass of the Sun and is radiating 12[6] times the Sun's luminosity from its photosphere at an effective temperature of roughly 7,872 K.[5]


  1. ^ a b c d e 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.
  2. ^ 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.
  3. ^ a b Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement Series, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182.
  4. ^ a b Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
  5. ^ a b c d e f 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.
  6. ^ a b c Zorec, J.; Royer, F. (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.
  7. ^ "10 Ser". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-03-19.
  8. ^ Eggleton, P. P.; Tokovinin, A. A. (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.
  9. ^ van Belle, Gerard T. (March 2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv:1204.2572, Bibcode:2012A&ARv..20...51V, doi:10.1007/s00159-012-0051-2.