Astronomy:Lambda Serpentis
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Serpens |
| Right ascension | 15h 46m 26.61423s[1] |
| Declination | +07° 21′ 11.0475″[1] |
| Apparent magnitude (V) | 4.43[2] |
| Characteristics | |
| Spectral type | G0 V[3] |
| U−B color index | +0.11[2] |
| B−V color index | +0.60[2] |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | −66.4[4] km/s |
| Proper motion (μ) | RA: −224.0±0.2[1] mas/yr Dec.: −69.8±0.3[1] mas/yr |
| Parallax (π) | 83.92 ± 0.15[1] mas |
| Distance | 38.87 ± 0.07 ly (11.92 ± 0.02 pc) |
| Absolute magnitude (MV) | 4.01[5] |
| Details | |
| Mass | 1.14[6] M☉ |
| Radius | 1.060±0.152[7] R☉ |
| Luminosity | 1.94[6] L☉ |
| Surface gravity (log g) | 4.09[8] cgs |
| Temperature | 5,884±4.4[9] K |
| Metallicity [Fe/H] | −0.03[8] dex |
| Rotational velocity (v sin i) | 3[10] km/s |
| Age | 3.8–6.7[11] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Lambda Serpentis, Latinized from λ Serpentis, is a star in the constellation Serpens, in its head (Serpens Caput). It has an apparent visual magnitude of 4.43,[2] making it visible to the naked eye. Based upon parallax measurements, this star lies at a distance of about 38.9 light-years (11.9 parsecs) from Earth.[1] Lambda Serpentis is moving toward the Solar System with a radial velocity of 66.4 km s−1.[4] In about 166,000 years, this system will make its closest approach of the Sun at a distance of 7.371 ± 0.258 light-years (2.260 ± 0.079 parsecs), before moving away thereafter.[12]
This star is 6% larger and 14% more massive than the Sun, although it has a similar stellar classification.[1] It is shining with nearly double the Sun's luminosity and this energy is being radiated from the star's outer atmosphere at an effective temperature of 5,884 K.[9] A periodicity of 1837 days (5.03 years) was suspected by Morbey & Griffith (1987),[13] but it is probably bound to stellar activity. However, McDonald Observatory team has set limits to the presence of one or more exoplanets[13] around Lambda Serpentis with masses between 0.16 and 2 Jupiter masses and average separations spanning between 0.05 and 5.2 Astronomical Units.
Planetary system
In 2020, a candidate planet was detected orbiting Lambda Serpentis (HD 141004). With a minimum mass of 0.043 |♃|J}}}}}} (13.6 M⊕) and an orbital period of 15 days, this would most likely be a hot Neptune.[14] The discovery of planet was confirmed in 2021.[15]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 0.0428+0.0047−0.0045 MJ | 0.1238±0.002 | 15.5083+0.0016−0.0018 | 0.16+0.11−0.10 | — | — |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 Johnson, H. L.; Morgan, W. W. (1953). "Fundamental stellar photometry for standards of spectral type on the revised system of the Yerkes spectral atlas". Astrophysical Journal 117: 313–352. doi:10.1086/145697. Bibcode: 1953ApJ...117..313J.
- ↑ 3.0 3.1 "lam Ser -- Spectroscopic binary". SIMBAD. Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Lambda+Serpentis.
- ↑ 4.0 4.1 Wilson, Ralph Elmer (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication (Washington: Carnegie Institution of Washington). Bibcode: 1953GCRV..C......0W.
- ↑ Holmberg, J. et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics 501 (3): 941–947, doi:10.1051/0004-6361/200811191, Bibcode: 2009A&A...501..941H.
- ↑ 6.0 6.1 Valenti, J. A.; Fishcer, D. A. (2005). "Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K Dwarfs from Keck, Lick, and AAT Planet Search Programs". Astrophysical Journal Supplement Series 159 (1): 141–166. doi:10.1086/430500. Bibcode: 2005ApJS..159..141V.
- ↑ van Belle, Gerard T.; von Braun, Kaspar (2009). "Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars". The Astrophysical Journal 694 (2): 1085–1098. doi:10.1088/0004-637X/694/2/1085. Bibcode: 2009ApJ...694.1085V.
- ↑ 8.0 8.1 Fuhrmann, Klaus (October 1998). "Nearby stars of the Galactic disk and halo". Astronomy and Astrophysics 338: 161–183. Bibcode: 1998A&A...338..161F.
- ↑ 9.0 9.1 Kovtyukh; Soubiran, C.; Belik, S. I.; Gorlova, N. I. (2003). "High precision effective temperatures for 181 F-K dwarfs from line-depth ratios". Astronomy and Astrophysics 411 (3): 559–564. doi:10.1051/0004-6361:20031378. Bibcode: 2003A&A...411..559K.
- ↑ Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". Contributi Osservatorio Astronomico di Padova in Asiago 239 (1): 1. Bibcode: 1970CoAsi.239....1B.
- ↑ Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008). "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics". The Astrophysical Journal 687 (2): 1264–1293. doi:10.1086/591785. Bibcode: 2008ApJ...687.1264M.
- ↑ Dybczyński, P. A. (April 2006), "Simulating observable comets. III. Real stellar perturbers of the Oort cloud and their output", Astronomy and Astrophysics 449 (3): 1233–1242, doi:10.1051/0004-6361:20054284, Bibcode: 2006A&A...449.1233D
- ↑ 13.0 13.1 Morbey, C. L.; Griffith, R. F. (1987). "On the reality of certain spectroscopic orbits". Astrophysical Journal 317 (1): 343–352. doi:10.1086/165281. Bibcode: 1987ApJ...317..343M.
- ↑ Hirsch, Lea A. et al. (2021), "Understanding the Impacts of Stellar Companions on Planet Formation and Evolution: A Survey of Stellar and Planetary Companions within 25 pc", The Astronomical Journal 161 (3): 134, doi:10.3847/1538-3881/abd639, Bibcode: 2021AJ....161..134H.
- ↑ 15.0 15.1 Rosenthal, Lee J.; Fulton, Benjamin J.; Hirsch, Lea A.; Isaacson, Howard T.; Howard, Andrew W.; Dedrick, Cayla M.; Sherstyuk, Ilya A.; Blunt, Sarah C. et al. (2021), "The California Legacy Survey. I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades", The Astrophysical Journal Supplement Series 255 (1): 8, doi:10.3847/1538-4365/abe23c, Bibcode: 2021ApJS..255....8R
Further reading
- Wittenmeyer, R. A. (2006). "Detection Limits from the McDonald Observatory Planet Search Program". Astronomical Journal 132 (1): 177–188. doi:10.1086/504942. Bibcode: 2006AJ....132..177W.
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