Wikipedia

Sigma Serpentis

σ Serpentis
Location of σ Serpentis (circled in red)
Observation data
Epoch J2000      Equinox J2000
Constellation Serpens
Right ascension 16h 22m 04.34822s[1]
Declination +01° 01′ 44.5566″[1]
Apparent magnitude (V) +4.82[2]
Characteristics
Evolutionary stage main sequence[1][3]
Spectral type F3 V[4]
U−B color index +0.025[2]
B−V color index +0.338[2]
Astrometry
Radial velocity (Rv)−49.3±0.9[5] km/s
Proper motion (μ) RA: −158.172 mas/yr[1]
Dec.: +50.612 mas/yr[1]
Parallax (π)35.5388±0.1366 mas[1]
Distance91.8 ± 0.4 ly
(28.1 ± 0.1 pc)
Absolute magnitude (MV)+2.63[6]
Details
Mass1.54[7] M☉
Radius1.81[7] R☉
Luminosity7.2[7] L☉
Surface gravity (log g)4.11[7] cgs
Temperature7,009[7] K
Metallicity [Fe/H]−0.01[8] dex
Rotational velocity (v sin i)77.7[6] km/s
Age1.15±0.10[8] Gyr
Other designations
σ Ser, 50 Serpentis, BD+01°3215, FK5 1427, HD 147449, HIP 80179, HR 6093, SAO 121540[9]
Database references
SIMBADdata

Sigma Serpentis, Latinized from σ Serpentis, is a star in the equatorial constellation Serpens. It is faintly visible to the naked eye with an apparent visual magnitude of +4.82.[2] Based upon an annual parallax shift of 35.54 mas as seen from Earth, it is located 92 light-years from the Sun. The star is moving closer to the Sun with a radial velocity of −49 km/s.[5]

Barry (1970) assigned this star a stellar classification of F3 V,[4] indicating an ordinary F-type main-sequence star. It is about one billion years old[8] and is spinning with a projected rotational velocity of 77.7 km/s.[6] The star has an estimated 1.5 times the mass of the Sun and is radiating 7.2 times the Sun's luminosity from its photosphere at an effective temperature of 7,009 K.[7]

A candidate red dwarf companion star, of spectral type M2V, was identified in 2012 by Kevin Luhman and collaborators. It is 43″ from the primary, corresponding to a projected separation of 1200 AU.[10] Gaia DR3 astrometry confirms a similar parallax and proper motion.[11]

References

[edit]
  1. ^ a b c d e 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.
  2. ^ a b c d Cousins, A. W. J. (1984), "Standardisation of broad band photometry of equatorial standards", South Africa Astronomical Observatory Circular, 8: 59–67, Bibcode:1984SAAOC...8...59C.
  3. ^ 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, S2CID 55586789.
  4. ^ a b Barry, Don C. (January 1970), "Spectral Classification of a and F Stars", Astrophysical Journal Supplement, 19: 281, Bibcode:1970ApJS...19..281B, doi:10.1086/190209.
  5. ^ a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
  6. ^ a b c Paunzen, E.; et al. (July 2014), "Investigating the possible connection between λ Bootis stars and intermediate Population II type stars", Astronomy & Astrophysics, 567: 8, arXiv:1406.3936, Bibcode:2014A&A...567A..67P, doi:10.1051/0004-6361/201423817, S2CID 56332289, A67.
  7. ^ a b c d e f 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.
  8. ^ a b c Pace, G. (March 2013), "Chromospheric activity as age indicator. An L-shaped chromospheric-activity versus age diagram", Astronomy & Astrophysics, 551: 4, arXiv:1301.5651, Bibcode:2013A&A...551L...8P, doi:10.1051/0004-6361/201220364, S2CID 56420519, L8.
  9. ^ "sig Ser", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-10-20.
  10. ^ Luhman, Kevin L.; Loutrel, Nicholas P.; et al. (December 2012). "New M, L, and T Dwarf Companions to Nearby Stars from the Wide-field Infrared Survey Explorer". The Astrophysical Journal. 760 (2): 152. arXiv:1211.3977. Bibcode:2012ApJ...760..152L. doi:10.1088/0004-637X/760/2/152.
  11. ^ "sig Ser B". SIMBAD. Centre de données astronomiques de Strasbourg.