HD 65216 is a triple[4] star system with two exoplanetary companions in the southern constellation of Carina. With an apparent visual magnitude of 7.97[2] it cannot be readily seen without technical aid, but with binoculars or telescope it should be visible. The system is located at a distance of 114.7 light-years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of 42.6 km/s.[1]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Carina |
| Right ascension | 07h 53m 41.3193s[1] |
| Declination | −63° 38′ 50.353″[1] |
| Apparent magnitude (V) | 7.97[2] |
| Characteristics | |
| Spectral type | G5V[3] + M7–8 + L2–3[4] |
| B−V color index | 0.672±0.012[2] |
| Astrometry | |
| Radial velocity (Rv) | 42.57±0.16[1] km/s |
| Proper motion (μ) | RA: −123.633±0.065 mas/yr[1] Dec.: 146.578±0.073 mas/yr[1] |
| Parallax (π) | 28.4445 ± 0.0317 mas[1] |
| Distance | 114.7 ± 0.1 ly (35.16 ± 0.04 pc) |
| Absolute magnitude (MV) | 5.22[2] |
| Details | |
| HD 65216 A | |
| Mass | 0.95±0.01[5] M☉ |
| Radius | 0.864±0.003[5] R☉ |
| Luminosity | 0.716±0.001[5] L☉ |
| Surface gravity (log g) | 4.53±0.01[5] cgs |
| Temperature | 5,718±8[5] K |
| Metallicity [Fe/H] | −0.17[6] dex |
| Rotational velocity (v sin i) | 1.308[6] km/s |
| Age | 1.7±0.5[5] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The primary, component A, is an ordinary G-type main-sequence star with a stellar classification of G5V.[3] It is nearly two billion years old[5] and is spinning with a projected rotational velocity of 1.3 km/s.[6] The star has 95% of the mass and 86% of the radius of the Sun. It is radiating 72% of the luminosity of the Sun from its photosphere at an effective temperature of 5,718 K.[5]
In 2008 a co-moving binary system of low mass companions were discovered at an angular separation of 7″ from the primary, which is equivalent to a projected separation of 253 AU at the distance of HD 65216. Component B is of class M7–8 (0.089 M☉) while component C is class L2–3 (0.078 M☉); both have a mass close to the sub-stellar limit. The pair have a projected separation of 6 AU from each other.[4]
Planetary system
editAn extrasolar planet (designated as HD 65216 b) was discovered orbiting the primary in 2003.[8] A second much more distant planet was suspected since 2013,[9] but was discovered on a completely different orbit in 2019.[10]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥1.295±0.062 MJ | 1.301±0.020 | 577.6±1.328 | 0.27±0.02 | — | — |
| c | ≥2.03±0.11 MJ | 5.75±0.09 | 5370±20 | 0.17±0.04 | — | — |
See also
editReferences
edit- ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data 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 source at VizieR.
- ^ a b c d Anderson, 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. S2CID 119257644.
- ^ a b Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 1. Ann Arbor, Michigan: Department of Astronomy, University of Michigan. Bibcode:1978mcts.book.....H.
- ^ a b c Mugrauer, M.; Seifahrt, A.; Neuhäuser, R. (July 2007). "The multiplicity of planet host stars - new low-mass companions to planet host stars". Monthly Notices of the Royal Astronomical Society. 378 (4): 1328–1334. arXiv:0704.1767. Bibcode:2007MNRAS.378.1328M. doi:10.1111/j.1365-2966.2007.11858.x. S2CID 14227351.
- ^ a b c d e f g h Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951.
- ^ a b c 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. arXiv:1912.08659. Bibcode:2020A&A...634A.136C. doi:10.1051/0004-6361/201936523. S2CID 209405391. A136.
- ^ "HD 65216". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-26.
- ^ Mayor, M.; et al. (2004). "The CORALIE survey for southern extra-solar planets XII. Orbital solutions for 16 extra-solar planets discovered with CORALIE". Astronomy and Astrophysics. 415 (1): 391–402. arXiv:astro-ph/0310316. Bibcode:2004A&A...415..391M. doi:10.1051/0004-6361:20034250.
- ^ Wittenmyer, Robert A.; et al. (2013). "Forever Alone? Testing Single Eccentric Planetary Systems for Multiple Companions". The Astrophysical Journal Supplement Series. 208 (1): 2. arXiv:1307.0894. Bibcode:2013ApJS..208....2W. doi:10.1088/0067-0049/208/1/2. S2CID 14109907.
- ^ a b Wittenmyer, Robert A.; et al. (2019). "Truly eccentric – I. Revisiting eight single-eccentric planetary systems". Monthly Notices of the Royal Astronomical Society. 484 (4): 5859–5867. arXiv:1901.08471. Bibcode:2019MNRAS.484.5859W. doi:10.1093/mnras/stz290.
External links
edit- "Notes for star HD 65216". Extrasolar Planets Encyclopaedia. Archived from the original on July 2, 2007. Retrieved 2008-08-22.