Astronomy:HD 204313
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Capricornus |
| Right ascension | 21h 28m 12.20609s[1] |
| Declination | −21° 43′ 34.5182″[1] |
| Apparent magnitude (V) | 7.99[2] |
| Characteristics | |
| Spectral type | G5V[3] |
| Apparent magnitude (B) | 8.687[2] |
| Apparent magnitude (J) | 6.812±0.024[2] |
| Apparent magnitude (H) | 6.539±0.040[2] |
| Apparent magnitude (K) | 6.459±0.018[2] |
| B−V color index | 0.697±0.022[2] |
| Astrometry | |
| Radial velocity (Rv) | −9.79±0.12[1] km/s |
| Proper motion (μ) | RA: 42.751[1] mas/yr Dec.: −270.443[1] mas/yr |
| Parallax (π) | 20.7705 ± 0.0343[1] mas |
| Distance | 157.0 ± 0.3 ly (48.15 ± 0.08 pc) |
| Absolute magnitude (MV) | 4.61[2] |
| Details | |
| Mass | 1.06±0.03[4] M☉ |
| Radius | 1.08±0.03[4] R☉ |
| Luminosity | 1.18±0.03[4] L☉ |
| Surface gravity (log g) | 4.39±0.04[4] cgs |
| Temperature | 5,783±48[4] K |
| Metallicity [Fe/H] | 0.18[5] dex |
| Rotational velocity (v sin i) | 0.846[5] km/s |
| Age | 4.3±1.8[4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| Extrasolar Planets Encyclopaedia | data |
HD 204313 is a star with two and possibly three exoplanetary companions in the southern constellation of Capricornus. With an apparent magnitude of 7.99,[2] it is an eighth magnitude star that is too faint to be readily visible to the naked eye. The star is located at a distance of 157 light years from the Sun based on parallax measurements, but it is drifting closer with a radial velocity of −10 km/s.[1]
This is an ordinary G-type main-sequence star with a stellar classification of G5V,[3] which indicates it is generating energy through hydrogen fusion at its core. It is an estimated four billion years old, chromospherically extremely quiet,[7] and is spinning with a projected rotational velocity of just 0.8 km/s.[5] The star has a slightly larger mass and radius compared to the Sun. It is radiating 118% of the luminosity of the Sun from its photosphere at an effective temperature of 5,783 K.[4]
Planetary system
This star was in observation by the CORALIE radial velocity planet-search program since the year 2000. In August 2009, a superjovian planetary companion was announced.[8] Two years later, a hot Neptune HD 204313 c on a 35-day orbit was announced,[9] followed by a third Jupiter-like planet candidate HD 204313 d on a 2800-day orbit, which was announced in 2012.[10] Assuming that planet d exists, planets b & d are apparently orbiting close to a 7:5 mean motion resonance, which may be stabilizing their periods.[11]
A 2015 study independently confirmed the first two discoveries, but did not detect any significant signal at the claimed period of planet d.[12] Another study in 2022 agreed with these results, in addition to finding a new planet or brown dwarf, designated HD 204313 e to differentiate it from the dubious candidate. The inclination and true mass of planets b & e were measured via astrometry.[13]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| c | ≥17.6±1.7 M⊕ | 0.2099±0.0071 | 34.905±0.012 | 0.059+0.051 −0.041 |
— | — |
| b | 4.615+1.290 −0.306 MJ |
3.185+0.130 −0.143 |
2041.1+1.7 −1.9 |
0.100±0.003 | 72.917+31.372 −21.476° |
— |
| e | 15.317+4.890 −5.183 MJ |
7.457+0.399 −0.427 |
7325.6+399.9 −369.1 |
0.253+0.071 −0.065 |
176.092+0.963 −2.122° |
— |
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 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 2.4 2.5 2.6 2.7 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1988mcts.book.....H
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Bonfanti, A.; Ortolani, S.; Nascimbeni, V. (2016). "Age consistency between exoplanet hosts and field stars". Astronomy & Astrophysics 585: 14. doi:10.1051/0004-6361/201527297. A5. Bibcode: 2016A&A...585A...5B.
- ↑ 5.0 5.1 5.2 Costa Silva, A. R. et al. (February 2020). "Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur". Astronomy & Astrophysics 634: 10. doi:10.1051/0004-6361/201936523. A136. Bibcode: 2020A&A...634A.136C.
- ↑ "HD 204313". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+204313.
- ↑ Robertson, Paul et al. (July 2012), "A Second Giant Planet in 3:2 Mean-motion Resonance in the HD 204313 System", The Astrophysical Journal 754 (1): 9, doi:10.1088/0004-637X/754/1/50, 50, Bibcode: 2012ApJ...754...50R.
- ↑ Ségransan, D. et al. (2010). "The CORALIE survey for southern extrasolar planets. XVI. Discovery of a planetary system around HD 147018 and of two long period and massive planets orbiting HD 171238 and HD 204313". Astronomy and Astrophysics 511: A45. doi:10.1051/0004-6361/200912136. Bibcode: 2010A&A...511A..45S. http://www.aanda.org/index.php?option=com_article&access=standard&Itemid=129&url=/articles/aa/full_html/2010/03/aa12136-09/aa12136-09.html.
- ↑ Mayor, M. et al. (September 2011), "The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets", eprint, Bibcode: 2011arXiv1109.2497M
- ↑ Robertson, Paul et al. (2012). "A Second Giant Planet in 3:2 Mean-motion Resonance in the HD 204313 System". The Astrophysical Journal 754 (1): 50. doi:10.1088/0004-637X/754/1/50. Bibcode: 2012ApJ...754...50R.
- ↑ Petit, A. C. et al. (November 2017), "AMD-stability in the presence of first-order mean motion resonances", Astronomy & Astrophysics 607: 17, doi:10.1051/0004-6361/201731196, A35, Bibcode: 2017A&A...607A..35P.
- ↑ 12.0 12.1 Díaz, R. F. et al. (2016). "The HARPS search for southern extra-solar planets. XXXVIII. Bayesian re-analysis of three systems. New super-Earths, unconfirmed signals, and magnetic cycles". Astronomy and Astrophysics 585: A134. doi:10.1051/0004-6361/201526729. Bibcode: 2016A&A...585A.134D. https://www.aanda.org/articles/aa/full_html/2016/01/aa26729-15/aa26729-15.html.
- ↑ 13.0 13.1 Feng, Fabo et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series 262 (21): 21. doi:10.3847/1538-4365/ac7e57. Bibcode: 2022ApJS..262...21F.
Coordinates: 
21h 28m 12.2063s, −21° 43′ 34.517″
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