Location of λ Serpentis (circled) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Serpens |
| Right ascension | 15 46 26.61423 |
| Declination | +07° 21′ 11.0475″ |
| Apparent magnitude (V) | 4.43 |
| Characteristics | |
| Spectral type | G0 V |
| U−B color index | +0.11 |
| B−V color index | +0.60 |
| Variable type | Suspected |
| Astrometry | |
| Radial velocity (Rv) | −66.4 km/s |
| Proper motion (μ) | RA: −224.0±0.2 mas/yr Dec.: −69.8±0.3 mas/yr |
| Parallax (π) | 83.92 ± 0.15 mas |
| Distance | 38.87 ± 0.07 ly (11.92 ± 0.02 pc) |
| Absolute magnitude (MV) | 4.01 |
| Details | |
| Mass | 1.09±0.04 M☉ |
| Radius | 1.363±0.031 R☉ |
| Luminosity | 1.98±0.023 L☉ |
| Surface gravity (log g) | 4.09 cgs |
| Temperature | 5,901±78 K |
| Metallicity | −0.03 dex |
| Rotation | 24.3+3.7 −4.9 d |
| Rotational velocity (v sin i) | 3 km/s |
| Age | 5.4±0.7 Gyr |
| Other designations | |
| λ Ser, 27 Serpentis, NSV 7246, BD+7°3023, HD 141004, HIP 77257, HR 5868, SAO 121186, 2MASS J15462661+0721109 | |
| 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, 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. Lambda Serpentis is moving toward the Solar System with a radial velocity of 66.4 km s. 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.
This star is 36% larger and 9% more massive than the Sun, although it has a similar stellar classification. 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 5,901 K. A periodicity of 1837 days (5.03 years) was suspected by Morbey & Griffith (1987), but it is probably bound to stellar activity. However, McDonald Observatory team has set limits to the presence of one or more exoplanets 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 MJ (13.6 ME) and an orbital period of 15 days, this would most likely be a hot Neptune. The discovery of planet was confirmed in 2021.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 0.0428 −0.0045 MJ |
0.1238±0.002 | 15.5083 −0.0018 |
0.16 −0.10 |
— | — |
References
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ 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. Bibcode:1953ApJ...117..313J. doi:10.1086/145697. S2CID 18072563.
- ^ "lam Ser -- Spectroscopic binary". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-12-15.
- ^ 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, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID 118577511.
- ^ Metcalfe, Travis S.; Buzasi, Derek; Huber, Daniel; Pinsonneault, Marc H.; van Saders, Jennifer L.; Ayres, Thomas R.; Basu, Sarbani; Drake, Jeremy J.; Egeland, Ricky; Kochukhov, Oleg; Petit, Pascal; Saar, Steven H.; See, Victor; Stassun, Keivan G.; Li, Yaguang (2023-09-21). "Asteroseismology and Spectropolarimetry of the Exoplanet Host Star λ Serpentis". The Astronomical Journal. 166 (4): 167. arXiv:2308.09808. Bibcode:2023AJ....166..167M. doi:10.3847/1538-3881/acf1f7. ISSN 0004-6256.
- ^ Fuhrmann, Klaus (October 1998). "Nearby stars of the Galactic disk and halo". Astronomy and Astrophysics. 338: 161–183. Bibcode:1998A&A...338..161F.
- 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.
- 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, Bibcode:2006A&A...449.1233D, doi:10.1051/0004-6361:20054284
- ^ Morbey, C. L.; Griffith, R. F. (1987). "On the reality of certain spectroscopic orbits". Astrophysical Journal. 317 (1): 343–352. Bibcode:1987ApJ...317..343M. doi:10.1086/165281.
- 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, arXiv:2012.09190, Bibcode:2021AJ....161..134H, doi:10.3847/1538-3881/abd639, S2CID 229297873.
- ^ Rosenthal, Lee J.; Fulton, Benjamin J.; Hirsch, Lea A.; Isaacson, Howard T.; Howard, Andrew W.; Dedrick, Cayla M.; Sherstyuk, Ilya A.; Blunt, Sarah C.; Petigura, Erik A.; Knutson, Heather A.; Behmard, Aida; Chontos, Ashley; Crepp, Justin R.; Crossfield, Ian J. M.; Dalba, Paul A.; Fischer, Debra A.; Henry, Gregory W.; Kane, Stephen R.; Kosiarek, Molly; Marcy, Geoffrey W.; Rubenzahl, Ryan A.; Weiss, Lauren M.; Wright, Jason T. (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, arXiv:2105.11583, Bibcode:2021ApJS..255....8R, doi:10.3847/1538-4365/abe23c, S2CID 235186973
Further reading
- Wittenmeyer, R. A.; et al. (2006). "Detection Limits from the McDonald Observatory Planet Search Program". Astronomical Journal. 132 (1): 177–188. arXiv:astro-ph/0604171. Bibcode:2006AJ....132..177W. doi:10.1086/504942. S2CID 16755455.
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