Astronomy:Sigma Serpentis
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| 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[1] mas/yr Dec.: +50.612[1] mas/yr |
| Parallax (π) | 35.5388 ± 0.1366[1] mas |
| Distance | 91.8 ± 0.4 ly (28.1 ± 0.1 pc) |
| Absolute magnitude (MV) | +2.63[6] |
| Details | |
| Mass | 1.54[7] M☉ |
| Radius | 1.81[7] R☉ |
| Luminosity | 7.2[7] L☉ |
| Surface gravity (log g) | 4.11[7] cgs |
| Temperature | 7,009[7] K |
| Metallicity [Fe/H] | −0.01[8] dex |
| Rotational velocity (v sin i) | 77.7[6] km/s |
| Age | 1.15±0.10[8] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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 astronomical unit|AU.[10] Gaia DR3 astrometry confirms a similar parallax and proper motion.[11]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 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.
- ↑ Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics 537: A120, doi:10.1051/0004-6361/201117691, Bibcode: 2012A&A...537A.120Z.
- ↑ 4.0 4.1 Barry, Don C. (January 1970), "Spectral Classification of a and F Stars", Astrophysical Journal Supplement 19: 281, doi:10.1086/190209, Bibcode: 1970ApJS...19..281B.
- ↑ 5.0 5.1 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, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D.
- ↑ 6.0 6.1 6.2 Paunzen, E. et al. (July 2014), "Investigating the possible connection between λ Bootis stars and intermediate Population II type stars", Astronomy & Astrophysics 567: 8, doi:10.1051/0004-6361/201423817, A67, Bibcode: 2014A&A...567A..67P.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 Stassun, Keivan G. et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S.
- ↑ 8.0 8.1 8.2 Pace, G. (March 2013), "Chromospheric activity as age indicator. An L-shaped chromospheric-activity versus age diagram", Astronomy & Astrophysics 551: 4, doi:10.1051/0004-6361/201220364, L8, Bibcode: 2013A&A...551L...8P.
- ↑ "sig Ser". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=sig+Ser.
- ↑ Luhman, Kevin L. 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. doi:10.1088/0004-637X/760/2/152. Bibcode: 2012ApJ...760..152L.
- ↑ "sig Ser B". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=sig+Ser+B.
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