HD 86226 is a star with a pair of orbiting exoplanet companions, found in the constellation of Hydra. With an apparent visual magnitude of 7.93,[2] it is too dim to be visible with the naked eye. The distance to this system has been determined by the parallax method, yielding a range of 149 light years. It is receding with a heliocentric radial velocity of +19.6 km/s.[4] A survey in 2015 has ruled out the existence of any stellar companions at projected distances above 12 astronomical units.[8]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Hydra |
| Right ascension | 09h 56m 29.844s[1] |
| Declination | –24° 05′ 57.80″[1] |
| Apparent magnitude (V) | 7.93[2] |
| Characteristics | |
| Spectral type | G2V[3] |
| Apparent magnitude (B) | 8.577[2] |
| Apparent magnitude (R) | 7.71[2] |
| Apparent magnitude (J) | 6.839±0.019[2] |
| Apparent magnitude (H) | 6.577±0.034[2] |
| Apparent magnitude (K) | 6.463±0.023[2] |
| B−V color index | 0.647±0.014[2] |
| V−R color index | 0.22[4] |
| Astrometry | |
| Radial velocity (Rv) | +19.56±0.19[4] km/s |
| Proper motion (μ) | RA: –177.127 mas/yr[1] Dec.: +47.099 mas/yr[1] |
| Parallax (π) | 21.9301 ± 0.0267 mas[1] |
| Distance | 148.7 ± 0.2 ly (45.60 ± 0.06 pc) |
| Absolute magnitude (MV) | 4.66[2] |
| Details[5] | |
| Mass | 1.019+0.061 −0.066 M☉ |
| Radius | 1.053+0.026 −0.026 R☉ |
| Luminosity | 1.180+0.036 −0.029 L☉ |
| Surface gravity (log g) | 4.400+0.029 −0.032 cgs |
| Temperature | 5863±88 K |
| Metallicity [Fe/H] | 0.018+0.057 −0.043 dex |
| Rotational velocity (v sin i) | 3.6[6] km/s |
| Age | 4.6+3.7 −2.7 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
This is an ordinary G-type main-sequence star with a stellar classification of G2V.[3] It is similar in size, mass, and composition to the Sun,[5] although it isn't considered a solar twin.[9] The age is about the same; roughly 4.6 billion years old. The star is radiating 18% greater luminosity (compared to the Sun) from its photosphere at an effective temperature of 5,863 K.[5] It is spinning with a projected rotational velocity of 3.6 km/s.[6]
As of 2014[update], Radio emission at a frequency of 150 MHz has been tentatively detected from the proximity of this system, although it is not clear whether the star or a satellite orbiting a rapidly rotating planet is the source.[10]
Planetary system
editDue to the periodic spectrum shifts when it had when placed under a Doppler test, 13 Magellan Doppler Velocity observations were made of an object found near the star. The object discovered in 2010 had a Keplerian orbit, was declared an exoplanet and dubbed HD 86226 b.[11] A hot Super-Earth planet called HD 86226 c was discovered in 2020.[5] It may be undergoing considerable atmospheric mass loss.[12]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| c | 7.25+1.19 −1.12 M🜨 |
0.049±0.001 | 3.98442±0.00018 | 0.075+0.065 −0.048 |
86.45+0.26 −0.16° |
2.16±0.08 R🜨 |
| b | 0.45+0.04 −0.05 MJ |
2.73±0.06 | 1628+22 −21 |
0.059+0.062 −0.039 |
— | — |
See also
edit- HD 129445
- HD 152079
- HD 164604
- HD 175167
- List of exoplanets discovered in 2010 - HD 86226 b
- List of exoplanets discovered in 2020 - HD 86226 c
References
edit- ^ a b c d Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data 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. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e f g h i 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; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H
- ^ a b c 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 e Teske, Johanna; et al. (2020). "TESS Reveals a Short-period Sub-Neptune Sibling (HD 86226c) to a Known Long-period Giant Planet". The Astronomical Journal. 160 (2): 96. arXiv:2007.13927. Bibcode:2020AJ....160...96T. doi:10.3847/1538-3881/ab9f95. S2CID 220830943.
- ^ a b Llorente de Andrés, F.; et al. (October 2021). "The evolution of lithium in FGK dwarf stars. The lithium-rotation connection and the Li desert". Astronomy and Astrophysics. 654: A137. arXiv:2108.05852. Bibcode:2021A&A...654A.137L. doi:10.1051/0004-6361/202141339. ISSN 0004-6361.
- ^ "HD 86226". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2010-02-10.
- ^ Mugrauer, M.; Ginski, C. (12 May 2015). "High-contrast imaging search for stellar and substellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society. 450 (3): 3127–3136. Bibcode:2015MNRAS.450.3127M. doi:10.1093/mnras/stv771. hdl:1887/49340. Retrieved 19 June 2020.
- ^ Datson, Juliet; et al. (February 2015). "Spectroscopic study of solar twins and analogues". Astronomy & Astrophysics. 574: 12. arXiv:1412.8168. Bibcode:2015A&A...574A.124D. doi:10.1051/0004-6361/201425000. S2CID 53708062. A124.
- ^ Sirothia, S. K.; et al. (February 2014). "Search for 150 MHz radio emission from extrasolar planets in the TIFR GMRT Sky Survey". Astronomy & Astrophysics. 562: 9. Bibcode:2014A&A...562A.108S. doi:10.1051/0004-6361/201321571. A108.
- ^ Arriagada, Pamela; et al. (2010). "Five Long-period Extrasolar Planets in Eccentric orbits from the Magellan Planet Search Program". The Astrophysical Journal. 711 (2): 1229–1235. arXiv:1001.4093. Bibcode:2010ApJ...711.1229A. doi:10.1088/0004-637X/711/2/1229. S2CID 118682009.
- ^ Gupta, Akash; Schlichting, Hilke E. (July 2021). "Caught in the act: core-powered mass-loss predictions for observing atmospheric escape". Monthly Notices of the Royal Astronomical Society. 504 (3): 4634–4648. arXiv:2103.08785. Bibcode:2021MNRAS.504.4634G. doi:10.1093/mnras/stab1128.
- ^ Marmier, M.; et al. (March 2013). "The CORALIE survey for southern extrasolar planets XVII. New and updated long period and massive planets". Astronomy and Astrophysics. 551: A90. arXiv:1211.6444. Bibcode:2013A&A...551A..90M. doi:10.1051/0004-6361/201219639. S2CID 59467665.
External links
edit- "HD 86226". SAO/NASA Astrophysics Data System (ADS) (Database query).