Astronomy:HAT-P-11b
 Size comparison of Neptune with HAT-P-11b (gray). | |
| Discovery[1] | |
|---|---|
| Discovered by | Bakos et al. |
| Discovery site | Cambridge, Massachusetts |
| Discovery date | 2 January 2009 |
| Transit (HATNet) | |
| Orbital characteristics | |
| astron|astron|helion}} | 0.0637+0.0020 −0.0019 AU |
| astron|astron|helion}} | 0.0413+0.0018 −0.0019 AU |
| 0.05254+0.00064 −0.00066 AU | |
| Eccentricity | 0.218+0.034 −0.031[2] |
| Orbital period | 4.887802443+0.000000034 −0.000000030[3] d |
| Inclination | 89.05+0.15 −0.09[3] |
| astron|astron|helion}} | 2454957.15+0.17 −0.20[2] |
| 19+14 −16[2] | |
| Semi-amplitude | 10.42+0.64 −0.66[2] |
| Star | HAT-P-11 |
| Physical characteristics | |
| Mean radius | 4.36±0.06[3] R⊕ |
| Mass | 23.4±1.5[2] M⊕ |
| Mean density | 1,440 kg/m3 (2,430 lb/cu yd) |
| 1.20 g | |
HAT-P-11b (or Kepler-3b) is an extrasolar planet orbiting the star HAT-P-11. It was discovered by the HATNet Project team in 2009 using the transit method, and submitted for publication on 2 January 2009.
This planet is located approximately 123 light-years (38 pc) distant from Earth.[4]
Discovery
The HATNet Project team initially detected the transits of HAT-P-11b from analysis of 11470 images, taken in 2004 and 2005, by the HAT-6 and HAT-9 telescopes. The planet was confirmed using 50 radial velocity measurements taken with the HIRES radial velocity spectrometer at W. M. Keck Observatory.[1]
At the time of its discovery HAT-P-11b was the smallest radius transiting extrasolar planet discovered by a ground based transit search and was also one of three previously known transiting planets within the initial field of view of the Kepler spacecraft.[1]
There was a linear trend in the radial velocities indicating the possibility of another planet in the system.[1] This planet, HAT-P-11c, was confirmed in 2018.[2]
Characteristics
This planet orbits about the same distance from the star as 51 Pegasi b is from 51 Pegasi, typical of transiting planets. However, the orbit of this planet is eccentric, at around 0.198, unusually high for hot Neptunes. HAT-P-11b's orbit is also highly inclined, with a tilt of 103+26−10°.[5] degrees relative to its star's rotation.[6][7] The planet is probably composed primarily of heavy elements with only 10% hydrogen and helium by mass, like Gliese 436 b.[1]
On 24 September 2014, NASA reported that HAT-P-11b is the first Neptune-sized exoplanet known to have a relatively cloud-free atmosphere and, as well, the first time molecules, namely water vapor, of any kind have been found on such a relatively small exoplanet.[8]
In 2009 French astronomers observed what was thought to be a weak unpolarized radio signal coming from the exoplanet, but it was not observed in a repeat observation in 2010.[9] If the signal was real, then it was probably due to intense lightning storms with similar properties as ones on Saturn.[10]
In December 2021 evidence of a magnetosphere was discovered in HAT-P-11b that could be the first ever in any exoplanet.[11][12][13]
See also
- Gliese 436 b
- HATNet Project
- HAT-P-7b
- Kepler Mission
- Tau Boötis b another extra solar planet with evidence of magnetic fields
- YZ Ceti another extra solar planet with evidence of magnetic fields
- HD 209458 b another extra solar planet with evidence of magnetic fields
References
- ↑ 1.0 1.1 1.2 1.3 1.4 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. doi:10.1088/0004-637X/710/2/1724. Bibcode: 2010ApJ...710.1724B.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 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. doi:10.3847/1538-3881/aabfec. Bibcode: 2018AJ....155..255Y.
- ↑ 3.0 3.1 3.2 Huber, K. F.; Czesla, S.; Schmitt, J. H. M. M. (2017). "Discovery of the secondary eclipse of HAT-P-11 b". Astronomy and Astrophysics 597: A113. doi:10.1051/0004-6361/201629699. Bibcode: 2017A&A...597A.113H. https://www.aanda.org/articles/aa/full_html/2017/01/aa29699-16/aa29699-16.html.
- ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ Albrecht, Simon; Winn, Joshua N.; Johnson, John A.; Howard, Andrew W.; Marcy, Geoffrey W.; Butler, R. Paul; Arriagada, Pamela; Crane, Jeffrey D. et al. (2012), "Obliquities of Hot Jupiter host stars: Evidence for tidal interactions and primordial misalignments", The Astrophysical Journal 757 (1): 18, doi:10.1088/0004-637X/757/1/18, Bibcode: 2012ApJ...757...18A
- ↑ "Inclined Orbits Prevail in Exoplanetary Systems". 12 January 2011. http://www.subarutelescope.org/Pressrelease/2010/12/20/index.html.
- ↑ Roberto Sanchis-Ojeda; Josh N. Winn; Daniel C. Fabrycky (2012). "Starspots and spin-orbit alignment for Kepler cool host stars". Astronomische Nachrichten 334 (1–2): 180–183. doi:10.1002/asna.201211765. Bibcode: 2013AN....334..180S.
- ↑ Clavin, Whitney; Chou, Felicia; Weaver, Donna; Villard; Johnson, Michele (24 September 2014). "NASA Telescopes Find Clear Skies and Water Vapor on Exoplanet". NASA. http://www.jpl.nasa.gov/news/news.php?release=2014-322&1. Retrieved 24 September 2014.
- ↑ Hodosán, G.; Rimmer, P. B.; Helling, Ch. (2016). "Lightning as a possible source of the radio emission on HAT-P-11b". Monthly Notices of the Royal Astronomical Society (ADS) 461 (2): 1222–1226. doi:10.1093/mnras/stw977. Bibcode: 2016MNRAS.461.1222H.
- ↑ Helling, Christiane; Rimmer, Paul B. (23 September 2019). "Lightning and charge processes in brown dwarf and exoplanet atmospheres". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 377 (2154): 20180398. doi:10.1098/rsta.2018.0398. PMID 31378171. Bibcode: 2019RSPTA.37780398H.
- ↑ Ben-Jaffel, Lotfi; Ballester, Gilda (2021) (in en), Signatures of Strong Magnetization and Metal-poor Atmosphere for a Neptune-Size Exoplanet, Institut d'astrophysique de Paris-CNRS, doi:10.48392/lbj-001, http://data.iap.fr/doi/bjaffel/20210727/, retrieved 2021-12-23
- ↑ "Astronomers Detect Signature of Magnetic Field on an Exoplanet" (in en). 2021-12-20. https://news.arizona.edu/story/astronomers-detect-signature-magnetic-field-exoplanet.
- ↑ O'Callaghan, Jonathan (2023-08-07). "Exoplanets Could Help Us Learn How Planets Make Magnetism" (in en). https://www.quantamagazine.org/exoplanets-could-help-us-learn-how-planets-make-magnetism-20230807/.
External links
- "HAT-P-11 b". Exoplanets. http://media4.obspm.fr/exoplanets/base/planete.php?etoile=HAT-P-11&planete=b.
Coordinates: 
19h 50m 50.2469s, +48° 04′ 51.085″
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