Astronomy:HAT-P-11b

From HandWiki
Short description: Super Neptune orbiting HAT-P-11
HAT-P-11b / Kepler-3b
Exoplanet Comparison HAT-P-11 b.png
Size comparison of Neptune with HAT-P-11b (gray).
Discovery[1]
Discovered byBakos et al.
Discovery siteCambridge, Massachusetts
Discovery date2 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
Eccentricity0.218+0.034
−0.031
[2]
Orbital period4.887802443+0.000000034
−0.000000030
[3] d
Inclination89.05+0.15
−0.09
[3]
astron|astron|helion}}2454957.15+0.17
−0.20
[2]
19+14
−16
[2]
Semi-amplitude10.42+0.64
−0.66
[2]
StarHAT-P-11
Physical characteristics
Mean radius4.36±0.06[3] R
Mass23.4±1.5[2] M
Mean density1,440 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

References

  1. 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. Bibcode2010ApJ...710.1724B. 
  2. 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. Bibcode2018AJ....155..255Y. 
  3. 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. Bibcode2017A&A...597A.113H. https://www.aanda.org/articles/aa/full_html/2017/01/aa29699-16/aa29699-16.html. 
  4. 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. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  5. 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, Bibcode2012ApJ...757...18A 
  6. "Inclined Orbits Prevail in Exoplanetary Systems". 12 January 2011. http://www.subarutelescope.org/Pressrelease/2010/12/20/index.html. 
  7. 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. Bibcode2013AN....334..180S. 
  8. 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. 
  9. 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. Bibcode2016MNRAS.461.1222H. 
  10. 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. Bibcode2019RSPTA.37780398H. 
  11. 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 
  12. "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. 
  13. 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

Coordinates: Sky map 19h 50m 50.2469s, +48° 04′ 51.085″