HAT-P-8
HAT-P-8 is a magnitude 10 star located 750 light-years away in Pegasus.[2] It is a F-type star about 28% more massive than the Sun.[3] Two red dwarf companions have been detected around HAT-P-8. The first has a spectral type of M5V and has a mass of 0.22 M☉. The second is even less massive, at 0.18 M☉, and its spectral type is M6V.[5]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 22h 52m 09.8629s[1] |
| Declination | +35° 26′ 49.605″[1] |
| Apparent magnitude (V) | 10.17[2] |
| Characteristics | |
| Spectral type | F[3] |
| Apparent magnitude (B) | 10.77 ± 0.04[2] |
| Apparent magnitude (V) | 10.36 ± 0.03[2] |
| Apparent magnitude (J) | 9.214 ± 0.022[2] |
| Apparent magnitude (H) | 9.004 ± 0.018[2] |
| Apparent magnitude (K) | 8.953 ± 0.013[2] |
| Astrometry | |
| Proper motion (μ) | RA: 75.235±1.044[1] mas/yr Dec.: 15.160±0.552[1] mas/yr |
| Parallax (π) | 4.56 ± 0.42[1] mas |
| Distance | 720 ± 70 ly (220 ± 20 pc) |
| Details | |
| Mass | 1.28 ± 0.04[3] M☉ |
| Radius | 1.58+0.08 −0.06[3] R☉ |
| Surface gravity (log g) | 4.19 ± 0.03[4] cgs |
| Temperature | 6223 ± 67[4] K |
| Metallicity [Fe/H] | -0.04 ± 0.08[4] dex |
| Rotational velocity (v sin i) | 12.6 ± 1.0[4] km/s |
| Age | 3.4 ± 1 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Extrasolar Planets Encyclopaedia | data |
Planetary system
In 2008 the HATNet Project announced the discovery of extrasolar planet HAT-P-8b around this star. This planet is a hot Jupiter gas giant planet.[3]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 1.354±0.035 MJ | 0.04496+0.00046 −0.00045 |
3.0763458±0.0000024 | <0.0060 | — | — |
See also
- HATNet Project
- List of extrasolar planets
References
- Brown, A. G. A; et al. (2016). "Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties". Astronomy and Astrophysics. 595. A2. arXiv:1609.04172. Bibcode:2016A&A...595A...2G. doi:10.1051/0004-6361/201629512. S2CID 1828208.Gaia Data Release 1 catalog entry
- "HAT-P-8". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2009-04-24.
- Latham, David W.; et al. (2009). "Discovery of a Transiting Planet and Eight Eclipsing Binaries in HATNet Field G205". The Astrophysical Journal. 704 (2): 1107–1119. arXiv:0812.1161. Bibcode:2009ApJ...704.1107L. doi:10.1088/0004-637X/704/2/1107.
- Torres, Guillermo; et al. (2012). "Improved Spectroscopic Parameters for Transiting Planet Hosts". The Astrophysical Journal. 757 (2). 161. arXiv:1208.1268. Bibcode:2012ApJ...757..161T. doi:10.1088/0004-637X/757/2/161. S2CID 16580774.
- Bechter, Eric B.; et al. (2014). "WASP-12b and HAT-P-8b are Members of Triple Star Systems". The Astrophysical Journal. 788 (1). 2. arXiv:1307.6857. Bibcode:2014ApJ...788....2B. doi:10.1088/0004-637X/788/1/2. S2CID 36306243.
- Mancini, L.; et al. (2013). "A lower radius and mass for the transiting extrasolar planet HAT-P-8 b". Astronomy and Astrophysics. 551. A11. arXiv:1212.3701. Bibcode:2013A&A...551A..11M. doi:10.1051/0004-6361/201220291. S2CID 118498705.
- Bonomo, A. S.; et al. (2017). "The GAPS Programme with HARPS-N at TNG . XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets". Astronomy and Astrophysics. 602. A107. arXiv:1704.00373. Bibcode:2017A&A...602A.107B. doi:10.1051/0004-6361/201629882. S2CID 118923163.
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