HD 3167is a single,[4]orange-hued star in thezodiacconstellationofPiscesthat hosts asystemwith threeexoplanets.[8][9]The star is too faint to be seen with the naked eye, having anapparent visual magnitudeof 8.97.[2]The distance to HD 3167 can be determined from its annualparallax shiftof21.1363masas measured by theGaiaspace observatory,[1]yielding a range of 154light years.It has a relatively highproper motion,traversing thecelestial sphereat the rate of0.204″per year.[10]Since it was first photographed during thePalomar observatory sky surveyin 1953, it had moved over12.5″by 2017.[5]The star is moving away from the Earth with an average heliocentricradial velocityof +19.5 km/s.[4]
| Observation data EpochJ2000EquinoxJ2000 | |
|---|---|
| Constellation | Pisces |
| Right ascension | 00h34m57.524s[1] |
| Declination | +04° 22′ 53.28″[1] |
| Apparent magnitude(V) | 8.97[2] |
| Characteristics | |
| Evolutionary stage | Main sequence |
| Spectral type | K0 V[3] |
| B−Vcolor index | 0.827±0.021 |
| Variable type | Constant[2] |
| Astrometry | |
| Radial velocity(Rv) | +19.5±0.1[4]km/s |
| Proper motion(μ) | RA:+107.569mas/yr[1] Dec.:−173.334mas/yr[1] |
| Parallax(π) | 21.1363 ± 0.0187mas[1] |
| Distance | 154.3 ± 0.1ly (47.31 ± 0.04pc) |
| Absolute magnitude(MV) | 5.67[2] |
| Details[5][6] | |
| Mass | 0.837+0.053 −0.043M☉ |
| Radius | 0.880+0.012 −0.013R☉ |
| Luminosity | 0.56[2]L☉ |
| Surface gravity(logg) | 4.47±0.05cgs |
| Temperature | 5,261±60K |
| Metallicity[Fe/H] | 0.04±0.05dex |
| Rotational velocity(vsini) | 1.7±1.1km/s |
| Age | 7.8±4.3Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an ordinaryK-type main-sequence starwith astellar classificationof K0 V[3]and no significantvariability.[2]The star has 86% of themass of the Sunand 86% of theSun's radius.[5]It is achromospherically inactive[4]star and is radiating 56%[2]of theSun's luminosityfrom itsphotosphereat aneffective temperatureof 5,261 K. The spin of the star displays a relatively lowprojected rotational velocityof around 1.7 km/s. It has a near solarmetallicity– a term astronomers use for the proportion of elements other than hydrogen and helium in astellar atmosphere.[5]
In 2019, a group of astronomers first reported that the orbits of the detected exoplanets hosted by the star are oddly unusual: two planets (HD 3167 c; HD 3167 d) revolve around the star onpolar orbits,i.e. orbits that pass over thepolesof the star.[11]Later, in October 2021, the third planet (HD 3167 b) was found to orbit around theequatorof the star instead, while confirming the other planets' orbital inclinations from the 2019 study.[12][13]
Planetary system
editIn 2016, data collected during the extended K2 mission of theKepler space telescopewas used to identify twotransiting exoplanetcandidates orbiting this star, designated HD 3167 b and HD 3167 c. This made it one of the closest and brightest such multi-transiting stars known at the time. The lack of chromospheric activity makes it ideal for the preciseradial velocity(RV) measurements needed to estimate the masses of its planets.[4]Follow-up RV observations showed additionalperturbationsignals beyond the two planets already identified.[14]This led to the discovery in 2017 of a third, non-transiting planet, designated HD 3167 d.[5]
The close-orbiting body HD 3167 b has a mass of 5.02MEand radius 1.70R🜨.It most likely has had its atmosphere stripped away by the host star, leaving arocky planetwith about 15% iron by mass. HD 3167 b is orbiting HD 3167 with a period of 23.03 hours, anorbital inclinationof 83.4°, and an assumedorbital eccentricityof zero – a circular orbit. Thesemimajor axisof its orbit is0.01815AU,or just four times the star's radius.[5]
The second planet, HD 3167 c, has an orbital period of 29.8454 days and an eccentricity of less than 0.267. The semimajor axis is0.1795 AU.It has 9.80MEand 3.01R🜨,giving it a low bulk density of1.97+0.94
−0.59g/cm3.[5]This suggests either a mini-Neptune[14]with a gaseous envelope consisting mainly of hydrogen and helium, or a planet consisting of mostly water. In 2020,transmission spectroscopymeasurements of its atmosphere strongly favored a model with a high (>700 × Solar) metallicity atmosphere, due to discovered molecular absorption bands which cannot be attributed to hydrogen or helium.[15]The incidentfluxfrom the host star is around 16 times the amount the Earth receives from the Sun, and it is less susceptible toatmospheric strippingthan HD 3167 b.
The orbital inclination of HD 3167 d is inclined at least 1.3° away from theorbital planesof the other two exoplanets. Its orbit is expected to remain stable for periods longer than 100 million years only if this inclination is less than 40°. It has an orbital period of8.509±0.045 d,placing it in between the other two orbits, and shows a minimum mass of 6.90ME.The true mass is most likely less than Neptune.[5]
A fourth planet, HD 3167 e, first suggested as a candidate in 2019,[11]was discovered in 2022 by the radial-velocity method.[16]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 4.97+0.24 −0.23M🜨 |
0.01796+0.00037 −0.00031 |
0.959641±0.000011 | 0 (fixed) | 83.4+4.6 −7.7° |
1.67+0.17 −0.10R🜨 |
| d | ≥4.33±0.45M🜨 | 0.0763±0.0015 | 8.4112±0.0052 | <0.12 | — | — |
| c | 11.13+0.78 −0.74M🜨 |
0.1776+0.0037 −0.0031 |
29.8454±0.0012 | <0.060 | 89.3+0.5 −1.0° |
3.00+0.45 −0.21R🜨 |
| e | ≥8.41±1.02M🜨 | 0.3885±0.0079 | 96.63±0.29 | <0.15 | — | — |
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.
- ^abcdefgAnderson, 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.
- ^abHouk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars",Michigan Spectral Survey,5,Bibcode:1999MSS...C05....0H.
- ^abcdeVanderburg, Andrew; et al. (September 2016), "Two Small Planets Transiting HD 3167",The Astrophysical Journal Letters,829(1): 6,arXiv:1607.05248,Bibcode:2016ApJ...829L...9V,doi:10.3847/2041-8205/829/1/L9,S2CID41001644,L9.
- ^abcdefghChristiansen, Jessie L.; Vanderburg, Andrew; et al. (September 2017), "Three's Company: An Additional Non-transiting Super-Earth in the Bright HD 3167 System, and Masses for All Three Planets",The Astronomical Journal,154(3): 17,arXiv:1706.01892,Bibcode:2017AJ....154..122C,doi:10.3847/1538-3881/aa832d,S2CID54196245,122.
- ^abBonomo, A. S.; Dumusque, X.; et al. (April 2023). "Cold Jupiters and improved masses in 38 Kepler and K2 small-planet systems from 3661 high-precision HARPS-N radial velocities. No excess of cold Jupiters in small-planet systems".Astronomy & Astrophysics.arXiv:2304.05773.doi:10.1051/0004-6361/202346211.S2CID261556620.
- ^"HD 3167".SIMBAD.Centre de données astronomiques de Strasbourg.RetrievedOctober 6,2018.
- ^Anderson, Natali (June 11, 2017),"HD 3167d: New Super-Earth Discovered around Nearby Star",Science News,Sci-News.com,retrievedOctober 7,2018.
- ^Nowakowski, Tomasz (July 20, 2016),"Two super-Earth-sized planets discovered orbiting a nearby star",Phys.org,Science X Network,retrievedOctober 7,2018.
- ^Lépine, Sébastien; Shara, Michael M. (March 2005), "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog) ",The Astronomical Journal,129(3): 1483–1522,arXiv:astro-ph/0412070,Bibcode:2005AJ....129.1483L,doi:10.1086/427854,S2CID2603568.
- ^abDalal, Shweta; et al. (2019), "Nearly polar orbit of the sub-Neptune HD 3167 c. Constraints on the dynamical history of a multi-planet system",Astronomy & Astrophysics,631(A28): 12,arXiv:1906.11013,Bibcode:2019A&A...631A..28D,doi:10.1051/0004-6361/201935944
- ^O'Callaghan, Jonathan (6 November 2021),"Star System With Right-Angled Planets Surprises Astronomers - Two planets orbit the poles while another revolves around the star's equator, suggesting a mysterious, undetected force",The New York Times,retrieved7 November2021.
- ^Bourrier, V.; et al. (27 October 2021), "The Rossiter–McLaughlin effect revolutions: an ultra-short period planet and a warm mini-Neptune on perpendicular orbits",Astronomy & Astrophysics,654(A152): A152,arXiv:2110.14214,Bibcode:2021A&A...654A.152B,doi:10.1051/0004-6361/202141527.
{{citation}}:CS1 maint: multiple names: authors list (link) - ^abGandolfi, Davide; et al. (September 2017), "The transiting multi-planet system HD3167: a 5.7MESuper-Earth and a 8.3MEmini-Neptune ",The Astronomical Journal,154(3): 15,arXiv:1706.02532,Bibcode:2017AJ....154..123G,doi:10.3847/1538-3881/aa832a,S2CID43466609,123.
- ^Mikal-Evans, Thomas; et al. (2020), "Transmission Spectroscopy for the Warm Sub-Neptune HD 3167c: Evidence for Molecular Absorption and a Possible High-metallicity Atmosphere",The Astronomical Journal,161(1): 18,arXiv:2011.03470,Bibcode:2021AJ....161...18M,doi:10.3847/1538-3881/abc874,S2CID226278240.
- ^Bourrier, V.; et al. (2022), "A CHEOPS-enhanced view of the HD 3167 system",Astronomy & Astrophysics,668:A31,arXiv:2209.06937,Bibcode:2022A&A...668A..31B,doi:10.1051/0004-6361/202243778,S2CID251861892