HD 162020
| Observation data EpochJ2000EquinoxJ2000 | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 17h50m38.35575s[1] |
| Declination | −40° 19′ 06.0723″[1] |
| Apparent magnitude(V) | 9.10[2] |
| Characteristics | |
| Spectral type | K3V[3] |
| B−Vcolor index | 0.964±0.066[2] |
| Astrometry | |
| Radial velocity(Rv) | −26.55±2.30[4]km/s |
| Proper motion(μ) | RA:+19.412mas/yr[1] Dec.:−25.799mas/yr[1] |
| Parallax(π) | 31.8624 ± 0.0622mas[1] |
| Distance | 102.4 ± 0.2ly (31.38 ± 0.06pc) |
| Absolute magnitude(MV) | 6.76[2] |
| Orbit[5] | |
| Period(P) | 8.4282388+0.0000014 −0.0000026d |
| Semi-major axis(a) | 0.0859±0.0010AU |
| Eccentricity(e) | 0.28126±0.00057 |
| Inclination(i) | 177.273+0.030 −0.027° |
| Longitude of the node(Ω) | 288.93+0.67 −0.73° |
| Periastronepoch(T) | 2457393.1874+0.0026 −0.0023 |
| Argument of periastron(ω) (secondary) | 28.70+0.13 −0.12° |
| Semi-amplitude(K1) (primary) | 1.8112+0.0013 −0.0016km/s |
| Details[5] | |
| Mass | 0.797±0.042M☉ |
| Radius | 0.770±0.017R☉ |
| Luminosity | 0.413+0.056 −0.050L☉ |
| Surface gravity(logg) | 4.567±0.028cgs |
| Temperature | 5,270+190 −180K |
| Metallicity[Fe/H] | −0.18+0.17 −0.19dex |
| Rotational velocity(vsini) | 1.9[6]km/s |
| Age | 5.7±4.7Gyr[7] 3.1±2.7[8]Gyr |
| HD 162020 b | |
| Mass | 0.39±0.02[9]M☉ |
| Mass | 410.8+5.8 −5.3MJup |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 162020is astarin the southernconstellationofScorpiuswith a likelyred dwarfcompanion. It has anapparent visual magnitudeof 9.10,[2]which is too faint to be visible to the naked eye. The distance to this system is 102light-years(31parsecs) based onstellar parallax.[1]It is drifting closer to theSunwith aradial velocityof −27 km/s,[4]and is predicted to come to within ~18 light-years in 1.1 million years.[11]
This is an ordinaryK-type main-sequence starwith astellar classificationof K3V.[3]The age estimate is poorly constrained but it appears to have an intermediate age of several billion years. However, theactivitylevel suggests a younger star; the rotation rate of the star may have been increased through synchronization with the companion, resulting in a higher than normal activity for its age.[6]X-ray emissionhas been detected from this star.[12]
HD 162020 has 74%[7]of themass of the Sunand 73%[4]of theSun's radius.The abundance of iron is roughly the same as the Sun, suggesting a similarmetallicity.It is radiating just 25.8% of theluminosity of the Sunfrom itsphotosphereat aneffective temperatureof 4,801 K.[4]The star is spinning with aprojected rotational velocityof 1.9 km/s.[6]
Companion
[edit]HD 162020 b is a companion, initially thought to be abrown dwarf,with aminimum massof15.0MJ.At the time of discovery, the actual mass was undetermined since theorbital inclinationwas not known. This object orbits very close to the star at adistanceof0.075AUwith aneccentricity(ovalness) of 0.277. The object's distance from the star ranges from 0.054 to 0.096 AU. It has an extremely high semi-amplitudeof 1,813 m/s. The discovery was announced on April 15, 2000 by theGeneva Extrasolar Planet Search Team.[13][6]
Despite the presence of this massive object in an eccentric orbit around the star, computer modelling done in 2017 (when the object was still thought to be a brown dwarf) showed it is still theoretically possible for an Earth-mass exoplanet to be occupying a dynamically-stable orbit in thehabitable zoneof this star.[14]
Anastrometricmeasurement of this object's true mass was published in 2022 as part ofGaia DR3,revealing it to be 0.39M☉and thus likely ared dwarfstar.[9]A full orbital solution was published in 2023.[5]
References
[edit]- ^abcdeVallenari, A.; et al. (Gaia collaboration) (2023)."GaiaData 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.S2CID244398875. Gaia DR3 record for this sourceatVizieR.
- ^abcdAnderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation".Astronomy Letters.38(5): 331.arXiv:1108.4971.Bibcode:2012AstL...38..331A.doi:10.1134/S1063773712050015.S2CID119257644.
- ^abTorres, C. A. O.; et al. (December 2006). "Search for associations containing young stars (SACY). I. Sample and searching method".Astronomy and Astrophysics.460(3): 695–708.arXiv:astro-ph/0609258.Bibcode:2006A&A...460..695T.doi:10.1051/0004-6361:20065602.S2CID16080025.
- ^abcdBrown, A. G. A.;et al. (Gaia collaboration) (August 2018)."GaiaData Release 2: Summary of the contents and survey properties ".Astronomy & Astrophysics.616.A1.arXiv:1804.09365.Bibcode:2018A&A...616A...1G.doi:10.1051/0004-6361/201833051.Gaia DR2 record for this sourceatVizieR.
- ^abcUnger, N.; Ségransan, D.; et al. (December 2023). "Exploring the brown dwarf desert with precision radial velocities and Gaia DR3 astrometric orbits".Astronomy & Astrophysics.680:A16.arXiv:2310.02758.Bibcode:2023A&A...680A..16U.doi:10.1051/0004-6361/202347578.
- ^abcdUdry, M.; et al. (2002)."The CORALIE survey for southern extra-solar planets VIII. The very low-mass companions of HD 141937, HD 162020, HD 168443, HD 202206: Brown dwarfs or" superplanets "?".Astronomy and Astrophysics.390(1): 267–279.arXiv:astro-ph/0202458.Bibcode:2002A&A...390..267U.doi:10.1051/0004-6361:20020685.S2CID9389274.
- ^abDelgado Mena, E.; et al. (April 2019). "Abundance to age ratios in the HARPS-GTO sample with Gaia DR2. Chemical clocks for a range of [Fe/H]".Astronomy & Astrophysics.624:24.arXiv:1902.02127.Bibcode:2019A&A...624A..78D.doi:10.1051/0004-6361/201834783.S2CID90259810.A78.
- ^Bonfanti, A.; Ortolani, S.; Nascimbeni, V. (2016). "Age consistency between exoplanet hosts and field stars".Astronomy & Astrophysics.585:A5, 14 pp.arXiv:1511.01744.Bibcode:2016A&A...585A...5B.doi:10.1051/0004-6361/201527297.S2CID53971692.
- ^abGaia Collaboration; et al. (June 2023). "Gaia Data Release 3: Stellar multiplicity, a teaser for the hidden treasure".Astronomy & Astrophysics.674:A34.arXiv:2206.05595.Bibcode:2023A&A...674A..34G.doi:10.1051/0004-6361/202243782.
- ^"HD 162020".SIMBAD.Centre de données astronomiques de Strasbourg.Retrieved2018-04-02.
- ^Bailer-Jones, C.A.L.; et al. (2018). "New stellar encounters discovered in the second Gaia data release".Astronomy & Astrophysics.616:A37.arXiv:1805.07581.Bibcode:2018A&A...616A..37B.doi:10.1051/0004-6361/201833456.S2CID56269929.
- ^Poppenhaeger, K.; Schmitt, J. H. M. M. (July 2011). "A Correlation Between Host Star Activity and Planet Mass for Close-in Extrasolar Planets?".The Astrophysical Journal.735(1): 5.arXiv:1106.0189.Bibcode:2011ApJ...735...59P.doi:10.1088/0004-637X/735/1/59.S2CID11359940.59.
- ^"Exoplanets Galore!"(Press release). Garching, Germany:European Southern Observatory.April 15, 2000.RetrievedDecember 30,2012.
- ^Agnew, Matthew T.; Maddison, Sarah T.; Thilliez, Elodie; Horner, Jonathan (2017)."Stable habitable zones of single Jovian planet systems".Monthly Notices of the Royal Astronomical Society.471(4): 4494–4507.arXiv:1706.05805.Bibcode:2017MNRAS.471.4494A.doi:10.1093/mnras/stx1449.S2CID119227856.
External links
[edit]- "Notes for star HD 162020".Extrasolar Planets Encyclopaedia.Archived fromthe originalon July 2, 2007.RetrievedDecember 21,2007.
- "Notes for planet HD 162020 b".Extrasolar Planets Encyclopaedia.RetrievedDecember 21,2007.
