HAT-P-28 is the primary of a binary star system about 1320 light-years away. It is a G-type main-sequence star. The star's age is older than the Sun's at 6.1+2.6
−1.9 billion years.[2] HAT-P-28 is slightly enriched in heavy elements, having a 130% concentration of iron compared to the Sun. Since 2014, the binary star system is suspected to be surrounded by a debris disk with a 6.1″(2500 AU) radius.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 00h 52m 00.1876s[1] |
| Declination | +34° 43′ 42.205″[1] |
| Apparent magnitude (V) | 13.03[2] |
| Characteristics | |
| Evolutionary stage | main-sequence star |
| Spectral type | G |
| Astrometry | |
| Radial velocity (Rv) | 48.06[3] km/s |
| Proper motion (μ) | RA: 25.615(14) mas/yr[1] Dec.: 2.712(11) mas/yr[1] |
| Parallax (π) | 2.4728 ± 0.0156 mas[1] |
| Distance | 1,319 ± 8 ly (404 ± 3 pc) |
| Orbit[4] | |
| Primary | HAT-P-28 |
| Companion | HAT-P-28 B |
| Semi-major axis (a) | 0.994±0.002" (404 AU) |
| Details[5] | |
| Mass | 1.02±0.05 M☉ |
| Radius | 1.10+0.09 −0.07 R☉ |
| Luminosity | 1.13+0.23 −0.16[2] L☉ |
| Surface gravity (log g) | 4.36±0.06[2] cgs |
| Temperature | 5680±90[2] K |
| Metallicity [Fe/H] | 0.12±0.08[2] dex |
| Rotational velocity (v sin i) | 0.2+0.5 −0.2[2] km/s |
| Age | 6.1+2.6 −1.9[2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The red dwarf stellar companion was detected in 2015 at a projected separation of 0.972″[7] and confirmed in 2016 to be either bound or comoving.[4]
Planetary system
editIn 2011 a transiting hot Jupiter planet b was detected on a nearly circular orbit. The planetary equilibrium temperature is 1384±52 K.[2] No orbital decay was detected as in 2018, despite the close proximity of the planet to the host star.[5]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.626±0.037 MJ | 0.0434±0.0007 | 3.257215±0.000007 | 0.051±0.033 | 88.0±0.9° | 1.190+0.102 −0.075 RJ |
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 j Buchhave, L. A.; Bakos, G. Á.; Hartman, J. D.; Torres, G.; Latham, D. W.; Andersen, J.; Kovács, G.; Noyes, R. W.; Shporer, A.; Esquerdo, G. A.; Fischer, D. A.; Johnson, J. A.; Marcy, G. W.; Howard, A. W.; Béky, B.; Sasselov, D. D.; Fűrész, G.; Quinn, S. N.; Stefanik, R. P.; Szklenár, T.; Berlind, P.; Calkins, M. L.; Lázár, J.; Papp, I.; Sári, P. (2011), "HAT-P-28b AND HAT-P-29b: TWO SUB-JUPITER MASS TRANSITING PLANETS", The Astrophysical Journal, 733 (2): 116, arXiv:1103.1813, Bibcode:2011ApJ...733..116B, doi:10.1088/0004-637X/733/2/116, S2CID 119293967
- ^ a b "HAT-P-28". SIMBAD. Centre de données astronomiques de Strasbourg.
- ^ a b Ngo, Henry; Knutson, Heather A.; Hinkley, Sasha; Bryan, Marta; Crepp, Justin R.; Batygin, Konstantin; Crossfield, Ian; Hansen, Brad; Howard, Andrew W.; Johnson, John A.; Mawet, Dimitri; Morton, Timothy D.; Muirhead, Philip S.; Wang, Ji (2016), "FRIENDS OF HOT JUPITERS. IV. STELLAR COMPANIONS BEYOND 50 au MIGHT FACILITATE GIANT PLANET FORMATION, BUT MOST ARE UNLIKELY TO CAUSE KOZAI–LIDOV MIGRATION", The Astrophysical Journal, 827 (1): 8, arXiv:1606.07102, Bibcode:2016ApJ...827....8N, doi:10.3847/0004-637X/827/1/8, S2CID 41083068
- ^ a b c Penev, Kaloyan; Bouma, L. G.; Winn, Joshua N.; Hartman, Joel D. (2018), "Empirical Tidal Dissipation in Exoplanet Hosts from Tidal Spin-up", The Astronomical Journal, 155 (4): 165, arXiv:1802.05269, Bibcode:2018AJ....155..165P, doi:10.3847/1538-3881/aaaf71, PMC 6510550, PMID 31080254, S2CID 64370118
- ^ Merín, Bruno; Ardila, David R.; Ribas, Álvaro; Bouy, Hervé; Bryden, Geoffrey; Stapelfeldt, Karl; Padgett, Deborah (2014), "Herschel/PACS photometry of transiting-planet host stars with candidate warm debris disks", Astronomy & Astrophysics, 569: A89, arXiv:1409.0572, Bibcode:2014A&A...569A..89M, doi:10.1051/0004-6361/201322956, S2CID 10038821
- ^ Wöllert, Maria; Brandner, Wolfgang (2015), "A Lucky Imaging search for stellar sources near 74 transit hosts", Astronomy & Astrophysics, 579: A129, arXiv:1506.05456, Bibcode:2015A&A...579A.129W, doi:10.1051/0004-6361/201526525, S2CID 118903879
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