Astronomy:WASP-31b

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Short description: Hot Jupiter orbiting the star WASP-31
WASP-31b
HotJupiter-Exoplanet-WASP-31b.jpg
"Hot Jupiter" exoplanet WASP-31b (artist concept)
Discovery
Discovered byAnderson, D.R. et al.[1]
Discovery siteWASP[2]
Discovery date2010[2]
Primary transit[2]
Orbital characteristics
0.04657±0.00034 AU
Eccentricity0[2]
Orbital period3.40591[2] d
Inclination84.54±0.027[2]
StarWASP-31[2]
Physical characteristics
Mean radius1.537±0.06[2] |♃|J}}}}}}
Mass0.478±0.03[2] ||J}}}}}}


WASP-31b is a low-density (puffy) "hot Jupiter" extrasolar planet orbiting the metal-poor (63% of solar metallicity) dwarf star WASP-31.[1] The exoplanet was discovered in 2010 by the WASP project.[2][1] WASP-31b is in the constellation of Crater,[3] and is about 1305 light-years[4] (light travel distance) from Earth.[2]

Characteristics

WASP-31b is a low-density (puffy) "hot Jupiter" exoplanet with a mass about 0.48 times that of Jupiter and a radius about 1.55 times that of Jupiter.[2][1] The planetary atmosphere has indeed the largest scale height, equal to 1150km, among exoplanets with measurable atmospheres as at 2021.[5]

The exoplanet orbits WASP-31, its host star, every 3.4 days.[2]

Comparison of "hot Jupiter" exoplanets, including WASP-31b
(top row; 3rd from left) (artist concept)

From top left to lower right: WASP-12b, WASP-6b, WASP-31b, WASP-39b, HD 189733b, HAT-P-12b, WASP-17b, WASP-19b, HAT-P-1b and HD 209458b.

In 2012, it was found from the Rossiter–McLaughlin effect that WASP-31b is orbiting the parent star in a prograde direction, with the WASP-31 star rotational axis inclined to the planetary orbit by 2.8±3.1 degrees.[6] The spectroscopic study in 2014 revealed that WASP-31b has a dense cloud deck overlaid by a hazy atmosphere.[7] WASP-31b was also reported to have significant amounts of potassium in its upper atmosphere, but the detection of potassium was refuted in 2015.[8] The potassium detection discrepancy was resolved in 2020 with the improved cloud deck model,[9] with the best fit being a very small amount of water over clouds and no potassium at all.[10]

Reanalysis of planetary spectroscopic data in 2020 has revealed the presence of chromium monohydride besides water.[11]

See also

References

  1. 1.0 1.1 1.2 1.3 Anderson, D.R. (2011). "WASP-31b: a low-density planet transiting a metal-poor, late-F-type dwarf star". Astronomy & Astrophysics 531: A60. doi:10.1051/0004-6361/201016208. Bibcode2011A&A...531A..60A. https://www.aanda.org/articles/aa/pdf/2011/07/aa16208-10.pdf. 
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 Staff (2018). "Planet WASP-31 b". Extrasolar Planets Encyclopaedia. https://exoplanet.eu/catalog/wasp_31_b--707/. Retrieved 2 March 2018. 
  3. DJM (2018). "Finding the constellation which contains given sky coordinates". djm.cc. http://djm.cc/constellation.html. Retrieved 2 March 2018. 
  4. Kyle (2018). "Convert Parsecs to Light Years". KylesConverter.com. http://www.kylesconverter.com/length/parsecs-to-light-years. Retrieved 2 March 2018. 
  5. Baxter, Claire; Désert, Jean-Michel; Tsai, Shang-Min; Todorov, Kamen O.; Bean, Jacob L.; Deming, Drake; Parmentier, Vivien; Fortney, Jonathan J. et al. (2021), "Evidence for disequilibrium chemistry from vertical mixing in hot Jupiter atmospheres", Astronomy & Astrophysics 648: A127, doi:10.1051/0004-6361/202039708 
  6. Brown, D. J. A.; Cameron, A. Collier; Anderson, D. R.; Enoch, B.; Hellier, C.; Maxted, P. F. L.; Miller, G. R. M.; Pollacco, D. et al. (2012). "Rossiter-Mc Laughlin effect measurements for WASP-16, WASP-25 and WASP-31★". Monthly Notices of the Royal Astronomical Society 423 (2): 1503–1520. doi:10.1111/j.1365-2966.2012.20973.x. Bibcode2012MNRAS.423.1503B. 
  7. The atmosphere of hot-Jupiter exoplanet WASP-31b
  8. Gibson, Neale P.; De Mooij, Ernst J W.; Evans, Thomas M.; Merritt, Stephanie; Nikolov, Nikolay; Sing, David K.; Watson, Chris (2019). "Revisiting the potassium feature of WASP-31b at high resolution". Monthly Notices of the Royal Astronomical Society 482 (1): 606–615. doi:10.1093/mnras/sty2722. Bibcode2019MNRAS.482..606G. 
  9. J. Chouqar, M. L. Morales, A. Daassou, A. Jabiri, Z. Benkhaldoun, Bruce G. Elmegreen, L. Viktor Tóth, Manuel Güdel, "Modeling the Transmission Spectra of WASP-31b"
  10. McGruder, Chima D.; López-Morales, Mercedes; Espinoza, Néstor; Rackham, Benjamin V.; Apai, Dániel; Jordán, Andrés; Osip, David J.; Alam, Munazza K. et al. (2020), "ACCESS: Confirmation of No Potassium in the Atmosphere of WASP-31b", The Astronomical Journal 160 (5): 230, doi:10.3847/1538-3881/abb806, Bibcode2020AJ....160..230M 
  11. Braam, Marrick; Van Der Tak, Floris F. S.; Chubb, Katy L.; Min, Michiel (2021), "Evidence for chromium hydride in the atmosphere of hot Jupiter WASP-31b", Astronomy & Astrophysics 646: A17, doi:10.1051/0004-6361/202039509, Bibcode2021A&A...646A..17B 

External links

Coordinates: Sky map 11h 17m 45.0s, −19° 03′ 17″