HD 66428
| Observation data Epoch J2000.0 Equinox ICRS | |
|---|---|
| Constellation | Monoceros |
| Right ascension | 08h 03m 28.66767s |
| Declination | −01° 09′ 45.7581″ |
| Apparent magnitude (V) | 8.25 |
| Characteristics | |
| Evolutionary stage | subgiant |
| Spectral type | G8IV(+G) |
| Astrometry | |
| Radial velocity (Rv) | 44.26±0.13 km/s |
| Proper motion (μ) | RA: −65.766±0.029 mas/yr Dec.: −206.999±0.019 mas/yr |
| Parallax (π) | 18.7661±0.0312 mas |
| Distance | 173.8 ± 0.3 ly (53.29 ± 0.09 pc) |
| Absolute magnitude (MV) | +4.56 |
| Details | |
| Mass | 1.09±0.02 M☉ |
| Radius | 1.13±0.03 R☉ |
| Luminosity | 1.28±0.01 L☉ |
| Surface gravity (log g) | 4.37±0.03 cgs |
| Temperature | 5,773±55 K |
| Age | 4.1±1.4 Gyr |
| Other designations | |
| BD−00°1891, HIP 39417, LTT 3038, SAO 135426 | |
| Database references | |
| SIMBAD | data |
HD 66428 is a G-type subgiant star located approximately 174 light-years away in the constellation of Monoceros. This star is similar to the Sun with an apparent magnitude of 8.25, an effective temperature of 5,705±27 K and a solar luminosity 1.28. Its absolute magnitude is 11.1 while its U-V color index is 0.71. It is considered an inactive star and it is metal-rich ([Fe/H] = 0.310). This star has a precise mass of 1.14552 solar masses. This precision comes from the Corot mission that measured asteroseismology.
Planetary system
In July 2006, the discovery of the extrasolar planet HD 66428 b was published in the Astrophysical Journal. It was found from observations at the W. M. Keck Observatory using the radial velocity method. It has a minimum mass of more than 3 times that of Jupiter and orbits at a distance of 3.47 AU away from the star.
In 2015 a refined orbit was determined which led to the discovery of a linear trend in the radial velocities indicating a more distant companion of unknown character, which was determined to be a gas giant planet HD 66428 c or brown dwarf in 2021. In 2022, the inclination and true mass of both planets were measured via astrometry. The orbital period and mass of planet c were found to be significantly lower than the previous higher-error estimates, showing it to be planetary mass and not a brown dwarf.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| b | 10.946+2.442 −3.845 MJ |
3.395+0.141 −0.157 |
6.214+0.015 −0.016 |
0.471±0.012 | 16.639+10.121 −2.959 |
— |
| c | 1.764+3.404 −0.041 MJ |
9.408+1.945 −1.267 |
28.690+9.206 −5.348 |
0.207+0.097 −0.098 |
93.938+57.003 −55.476 |
— |
See also
References
- 1 2 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.
- 1 2 3 4 5 6 7 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.
- 1 2 3 Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv:astro-ph/0607493. Bibcode:2006ApJ...646..505B. doi:10.1086/504701. S2CID 119067572.
- ↑ Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars, Vol. 5". Michigan Spectral Survey. 5. Bibcode:1999MSS...C05....0H.
- 1 2 3 4 5 6 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. S2CID 54555839.
- ↑ Kashyap, V.L.; et al. (2008). "Extrasolar Giant Planets and X-Ray Activity". Astrophysical Journal. 687 (2): 1339–1356. arXiv:0807.1308. Bibcode:2008ApJ...687.1339K. doi:10.1086/591922. S2CID 17515630.
- ↑ Sousa, S.G.; et al. (2008). "Spectroscopic parameters for 451 stars in the HARPS GTO planet search program". Astronomy and Astrophysics. 487 (1): 373–381. arXiv:0805.4826. Bibcode:2008A&A...487..373S. doi:10.1051/0004-6361:200809698. S2CID 18173201.
- 1 2 Feng, Y. Katherina; et al. (2015). "The California Planet Survey IV: A Planet Orbiting the Giant Star HD 145934 and Updates to Seven Systems with Long-period Planets". The Astrophysical Journal. 800 (1). 22. arXiv:1501.00633. Bibcode:2015ApJ...800...22F. doi:10.1088/0004-637X/800/1/22. S2CID 56390823.
- ↑ Rosenthal, Lee J.; Fulton, Benjamin J.; Hirsch, Lea A.; Isaacson, Howard T.; Howard, Andrew W.; Dedrick, Cayla M.; Sherstyuk, Ilya A.; Blunt, Sarah C.; Petigura, Erik A.; Knutson, Heather A.; Behmard, Aida; Chontos, Ashley; Crepp, Justin R.; Crossfield, Ian J. M.; Dalba, Paul A.; Fischer, Debra A.; Henry, Gregory W.; Kane, Stephen R.; Kosiarek, Molly; Marcy, Geoffrey W.; Rubenzahl, Ryan A.; Weiss, Lauren M.; Wright, Jason T. (2021). "The California Legacy Survey. I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades". The Astrophysical Journal Supplement Series. 255 (1): 8. arXiv:2105.11583. Bibcode:2021ApJS..255....8R. doi:10.3847/1538-4365/abe23c. S2CID 235186973.
- 1 2 Feng, Fabo; Butler, R. Paul; et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series. 262 (21): 21. arXiv:2208.12720. Bibcode:2022ApJS..262...21F. doi:10.3847/1538-4365/ac7e57. S2CID 251864022.
External links
- "Notes for star HD 66428". Extrasolar Planets Encyclopaedia. Archived from the original on August 11, 2007. Retrieved 2008-08-20.
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