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HAT-P-11

Coordinates: Sky map 19h 50m 50.2469s, +48° 04′ 51.085″
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(Redirected from HAT-P-11c)
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]
Distance123.42 ± 0.05 ly
(37.84 ± 0.02 pc)
Absolute magnitude (MV)6.57±0.09[3]
Details
Mass0.81+0.03
−0.02
[3] M
Radius0.683±0.009[6] R
Luminosity0.26±0.02[3] L
Surface gravity (log g)4.59±0.03[3] cgs
Temperature4780±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
Age6.5+5.9
−4.1
[3] Gyr
Other designations
HAT-P-11, BD+47°2936, HIP 97657, NLTT 48335, Kepler-3, KOI-3, KIC 10748390, TOI-1144, TIC 28230919, TYC 3561-2092-1, GSC 03561-02092[4]
Database references
SIMBADdata
KICdata

HAT-P-11, also designated GSC 03561-02092 and Kepler-3, is a metal-rich orange dwarf star with a planetary system, 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 spots are similar in distribution to those on the Sun, but HAT-P-11 is a more active star and has a starspot coverage approximately 100 times greater than the Sun.[8] The star appears to have an unusually small radius, which can be explained by the anomalously high helium fraction.[9]

Planetary system

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Artist Illustration of planet HAT-P-11b.[10]

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.[11]

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.[12] 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.[13]

Multiple 2024 studies present conflicting results about HAT-P-11c. One 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.[11] Another study instead claims further confirmation of the previously proposed planet.[14] A third paper, published in response to the first, also corroborates the planetary nature of HAT-P-11c based on additional radial velocity data.[15]

The HAT-P-11 planetary system[11][14]
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 3.06±0.42 MJ 4.19±0.07 3473.53+69.40
−62.09
0.560±0.036 143.6+4.7
−6.2
°

See also

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References

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  1. ^ 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
  2. ^ 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.
  3. ^ 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.
  4. ^ a b "BD+47 2936". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2009-04-22.
  5. ^ 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
  6. ^ 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.
  7. ^ 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.
  8. ^ Morris, Brett M.; Hebb, Leslie; et al. (September 2017). "The Starspots of HAT-P-11: Evidence for a Solar-like Dynamo". The Astrophysical Journal. 846 (2): 99. arXiv:1708.02583. Bibcode:2017ApJ...846...99M. doi:10.3847/1538-4357/aa8555.
  9. ^ 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
  10. ^ "Clear skies on exo-Neptune". www.spacetelescope.org. ESA/Hubble. Retrieved 25 September 2014.
  11. ^ a b c Basilicata, M.; Giacobbe, P.; et al. (June 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. 686: A127. arXiv:2403.01527. Bibcode:2024A&A...686A.127B. doi:10.1051/0004-6361/202347659.
  12. ^ 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.
  13. ^ 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
  14. ^ a b An, Qier; Lu, Tiger; et al. (May 2024). "Significant mutual inclinations between the stellar spin and the orbits of both planets in the HAT-P-11 system". arXiv:2405.19510 [astro-ph.EP].
  15. ^ Yee, Samuel W.; Petigura, Erik A.; et al. (July 2024). "Additional Doppler Monitoring Corroborates HAT-P-11 c as a Planet". Research Notes of the American Astronomical Society. 8 (7): 187. arXiv:2407.11109. Bibcode:2024RNAAS...8..187Y. doi:10.3847/2515-5172/ad675e.
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