HD 86226

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Wikipedia

HD 86226
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Hydra[1]
Right ascension 09h 56m 29.844s[2]
Declination −24° 05′ 57.80″[2]
Apparent magnitude (V) 7.93[1]
Characteristics
Evolutionary stage main sequence[2]
Spectral type G2V[3]
Apparent magnitude (B) 8.577[1]
Apparent magnitude (R) 7.71[1]
Apparent magnitude (J) 6.839±0.019[1]
Apparent magnitude (H) 6.577±0.034[1]
Apparent magnitude (K) 6.463±0.023[1]
B−V color index 0.647±0.014[1]
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[2]
Dec.: +47.099 mas/yr[2]
Parallax (π)21.9301±0.0267 mas[2]
Distance148.7 ± 0.2 ly
(45.60 ± 0.06 pc)
Absolute magnitude (MV)4.66[1]
Details[5]
Mass1.08±0.05 M☉
Radius1.03±0.02 R☉
Luminosity1.24+0.09
−0.07 L☉
Surface gravity (log g)4.41±0.02 cgs
Temperature6,007+75
−71 K
Metallicity [Fe/H]−0.015±0.041 dex
Rotation22.8±3.0 days
Rotational velocity (v sin i)3.6[6] km/s
Age3.8±1.8 Gyr
Other designations
CD−23°8866, HD 86226, HIP 48739, SAO 178205, PPM 256971[7]
Database references
SIMBADdata
Exoplanet Archivedata

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,[1] 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]

Description

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,[9] although it is not considered a solar twin.[10] The age is about 3.8 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.[9] It is spinning with a projected rotational velocity of 3.6 km/s.[6]

As of 2014, 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.[11]

Planetary system

Due 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.[12] A hot Super-Earth planet called HD 86226 c was discovered in 2020.[9] It may be undergoing considerable atmospheric mass loss.[13]

The HD 86226 planetary system
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
c 7.25+1.19
−1.12[9] M🜨		 0.049±0.001[9] 3.984436±0.000217[5] 0.06±0.08[5] 86.45+0.26
−0.16[9]°		 2.16±0.08[9] R🜨
b 0.46±0.04[5] MJ 2.73±0.06[14] 1,609.5±19.4[5] 0.04±0.07[5] — —

See also

References

  1. 1 2 3 4 5 6 7 8 9 10 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. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 6 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.
  3. 1 2 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.
  4. 1 2 3 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.
  5. 1 2 3 4 5 6 Delisle, J.-B.; Faria, J. P.; Ségransan, D.; Fontanet, E.; Ceva, W.; Barbato, D.; Sousa, S. G.; Unger, N.; Leleu, A. (2025-09-30). "Architecture of planetary systems with and without outer giant planets I. Inner planet detections around HD 23079, HD 196067, and HD 86226". arXiv:2509.26232 [astro-ph.EP].
  6. 1 2 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.
  7. ↑ "HD 86226". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2010-02-10.
  8. ↑ 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.
  9. 1 2 3 4 5 6 7 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.
  10. ↑ 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.
  11. ↑ 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.
  12. ↑ 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.
  13. ↑ 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.
  14. ↑ 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.