HAT-P-11
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus[1] |
| Right ascension | 19h 50m 50.2473s[2] |
| Declination | +48° 04′ 51.101″[2] |
| Apparent magnitude (V) | 9.59[3] |
| Characteristics | |
| Spectral type | K4V[3] |
| Apparent magnitude (B) | 10.66±0.05[4] |
| Apparent magnitude (J) | 7.608±0.029[5] |
| Apparent magnitude (H) | 7.131±0.021[5] |
| Apparent magnitude (K) | 7.009±0.020[5] |
| Variable type | planetary transit[3] |
| Astrometry | |
| Radial velocity (Rv) | −63.46±0.13[2] km/s |
| Proper motion (μ) | RA: 126.095(13) mas/yr[2] Dec.: 232.726(13) mas/yr[2] |
| Parallax (π) | 26.4274 ± 0.0108 mas[2] |
| Distance | 123.42 ± 0.05 ly (37.84 ± 0.02 pc) |
| Absolute magnitude (MV) | 6.57±0.09[3] |
| Details | |
| Mass | 0.81+0.03 −0.02[3] M☉ |
| Radius | 0.683±0.009[6] R☉ |
| Luminosity | 0.26±0.02[3] L☉ |
| Surface gravity (log g) | 4.59±0.03[3] cgs |
| Temperature | 4780±50[3] K |
| Metallicity [Fe/H] | 0.31±0.05[3] dex |
| Rotation | ~29.2 days[3] |
| Rotational velocity (v sin i) | 1.5±1.5[3] km/s |
| Age | 6.5+5.9 −4.1[3] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| KIC | data |
HAT-P-11, also designated GSC 03561-02092 and Kepler-3, is an orange dwarf metal rich star 123 light-years (38 parsecs) away in the constellation Cygnus. This star is notable for its relatively large rate of proper motion. The apparent magnitude of this star is about 9.6, which means it is not visible to the naked eye but can be seen with a medium-sized amateur telescope on a clear dark night. The age of this star is about 6.5 billion years.[3]
The star has active latitudes that generate starspots.[7] The star appears to have an unusually small radius, which can be explained by the anomalously high helium fraction.[8]
Planetary system[edit]
An exoplanet, designated HAT-P-11b, was discovered by the HATNet Project using the transit method, believed to be a little larger than the planet Neptune.[3]
The planet orbits out of alignment from the star's spin axis, with an obliquity of about 100°.[7] This star system was within the field of view of the Kepler Mission planet-hunter spacecraft.[3] Water vapor and ammonia have been detected in the atmosphere of HAT-P-11b.[10]
A trend in the radial velocity measurements taken to confirm the planet indicated a possible additional body in the system.[3] This was confirmed in 2018 when a second planet, HAT-P-11c, was detected on an approximately nine-year orbit.[11] In 2020, an astrometric detection of HAT-P-11c was published, along with Pi Mensae b, allowing its inclination and true mass to be determined.[12]
However, a 2024 study suggests that the radial velocity variations attributed to HAT-P-11c may actually be caused by a magnetic activity cycle of the star. If this is the case, an outer planet may still exist given the evidence for one from astrometry, but farther from the star and with a different mass than previously thought.[10]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 25.0±1.5 M🜨 | 0.0532±0.0010 | 4.887802443(34) | 0.2577+0.0033 −0.0025 |
89.027±0.068° | 4.901±0.065 R🜨 |
| c (disputed) | 2.3+0.7 −0.5 MJ |
4.13+0.29 −0.16 |
3397+71 −64 |
0.604±0.03 | 135.7+12.1 −21.4° |
— |
See also[edit]
References[edit]
- ^ Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific. 99 (617): 695–699. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Vizier query form
- ^ a b c d e 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 k l m n o p Bakos, G. Á.; et al. (2010). "HAT-P-11b: A Super-Neptune Planet Transiting a Bright K Star in the Kepler Field". The Astrophysical Journal. 710 (2): 1724–1745. arXiv:0901.0282. Bibcode:2010ApJ...710.1724B. doi:10.1088/0004-637X/710/2/1724.
- ^ a b "BD+47 2936". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2009-04-22.
- ^ a b c Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W.; Chester, Thomas; Elias, Jonathan H.; Huchra, John P.; Liebert, James W.; Lonsdale, Carol J.; Monet, David G.; Price, Stephan; Seitzer, Patrick; Jarrett, Thomas H.; Kirkpatrick, J. Davy; Gizis, John E.; Howard, Elizabeth V.; Evans, Tracey E.; Fowler, John W.; Fullmer, Linda; Hurt, Robert L.; Light, Robert M.; Kopan, Eugene L.; Marsh, Kenneth A.; McCallon, Howard L.; Tam, Robert; Van Dyk, Schuyler D.; Wheelock, Sherry L. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163–1183. Bibcode:2006AJ....131.1163S. doi:10.1086/498708. ISSN 0004-6256. S2CID 18913331. Vizier catalog entry
- ^ Deming, Drake; et al. (2011). "Kepler and Ground-based Transits of the Exo-Neptune HAT-P-11b". The Astrophysical Journal. 740 (1). 33. arXiv:1107.2977. Bibcode:2011ApJ...740...33D. doi:10.1088/0004-637X/740/1/33.
- ^ a b Sanchis-Ojeda, R.; Winn, J. N.; Fabrycky, D. C. (2012). "Starspots and spin-orbit alignment for Kepler cool host stars". Astronomische Nachrichten. 334 (1–2): 180–183. arXiv:1211.2002. Bibcode:2013AN....334..180S. doi:10.1002/asna.201211765. S2CID 38743202.
- ^ Maxted, P. F. L.; Serenelli, A. M.; Southworth, J. (2015), "Comparison of gyrochronological and isochronal age estimates for transiting exoplanet host stars", Astronomy & Astrophysics, 577: A90, arXiv:1503.09111, Bibcode:2015A&A...577A..90M, doi:10.1051/0004-6361/201525774, S2CID 53324330
- ^ "Clear skies on exo-Neptune". www.spacetelescope.org. ESA/Hubble. Retrieved 25 September 2014.
- ^ a b c Basilicata, M.; Giacobbe, P.; et al. (March 2024). "The GAPS Programme at TNG LV. Multiple molecular species in the atmosphere of HAT-P-11 b and review of the HAT-P-11 planetary system". Astronomy & Astrophysics. arXiv:2403.01527. doi:10.1051/0004-6361/202347659.
- ^ a b Yee, Samuel W.; et al. (2018). "HAT-P-11: Discovery of a Second Planet and a Clue to Understanding Exoplanet Obliquities". The Astronomical Journal. 155 (6). 255. arXiv:1805.09352. Bibcode:2018AJ....155..255Y. doi:10.3847/1538-3881/aabfec.
- ^ a b Xuan, Jerry W.; Wyatt, Mark C. (2020), "Evidence for a high mutual inclination between the cold Jupiter and transiting super Earth orbiting π Men", Monthly Notices of the Royal Astronomical Society, 497 (2): 2096–2118, arXiv:2007.01871, Bibcode:2020MNRAS.497.2096X, doi:10.1093/mnras/staa2033
External links[edit]
- "Planet HAT-P-11 b". Extrasolar Planets Encyclopaedia. Retrieved 2018-09-30.