WASP-19b / Banksia
Size comparison of WASP-19b with Jupiter.
Discovery[1]
Discovered byHebb et al. (SuperWASP)
Discovery dateDecember 10, 2009
Transit
Designations
Banksia[2]
Orbital characteristics
0.01655 ± 0.00013 AU (2,476,000 ± 19,000 km)
Eccentricity0.0046+0.0044
−0.0028[3]
0.79 ± 0.0000003 d (18.9600000 ± 7.2×10−6 h; 68,256.000 ± 0.026 s)[1]
Inclination79.4±0.4[3]
StarWASP-19
Physical characteristics
Mean radius
1.386±0.032[3] RJ
Mass1.168±0.023[3] MJ
Mean density
680 kg/m3 (1,150 lb/cu yd)
Albedo<0.26 [4]
0.16±0.04[5]
Temperature2350+168
−314[6]
2240±40[5]

WASP-19b, formally named Banksia,[2] is an exoplanet, notable for possessing one of the shortest orbital periods of any known planetary body: 0.79 days or approximately 18.932 hours. It has a mass close to that of Jupiter (1.15 Jupiter masses), but by comparison has a much larger radius (1.31 times that of Jupiter, or 0.13 Solar radii); making it nearly the size of a low-mass star.[1] It orbits the star WASP-19 in the Vela constellation. At the time of discovery it was the shortest period hot Jupiter discovered as planets with shorter orbital periods had a rocky, or metallic composition.

A study in 2012, utilizing the Rossiter–McLaughlin effect, determined the planetary orbit is well aligned with the equatorial plane of the star, misalignment equal to -15±11°.[7]

In 2013, secondary eclipse and orbital phases were barely observed from the data gathered with ASTEP telescope, making it the first detection of such kind through ground-based observations. This was possible due to the large size of the planet and its small semi-major axis.[4]

In 2019 the planet was observed with TESS and the eclipse of the planet was measured. The broad variations caused by the changing aspect of the heated face of the planet were measured. The study deduced that the dayside has a temperature of 2240 ± 40 K (1967 ± 40 °C) and that the planet reflects 16 ± 4 percent of the light that falls on it. The last value is relatively high compared to other planets.[8][5]

Despite the short orbital period, orbital decay of WASP-19b was not detected as of 2019.[9]

Nomenclature

In August 2022, this planet and its host star were included among 20 systems to be named by the third NameExoWorlds project.[10] The approved names, proposed by a team from Brandon Park Primary School in Wheelers Hill (Melbourne, Australia), led by scientist Lance Kelly and teacher David Maierhofer [11] were announced in June 2023. WASP-19b is named Banksia and its host star is named Wattle, after the Banksia and wattle plants.[2]

Atmosphere

In December 2013, scientists working with the Hubble Space Telescope reported detecting water in the atmosphere of the exoplanet.[12][13]

In September 2017, astronomers using the Very Large Telescope at the European Southern Observatory reported the detection of titanium oxide (TiO) in WASP-19b's atmosphere.[6] This was the first time titanium oxide had been detected in an exoplanet atmosphere.[14] They also detected a strongly scattering haze in the atmosphere as well as the element sodium, and additionally confirmed the presence of water.[6] Strong haze and barely discernible titanium oxide signal were confirmed in 2021, while no sign of water or alkali metals can be found.[15]

A study using TESS data concluded that the atmosphere of WASP-19b is moderately efficient at transporting heat from the dayside to the nightside.[5]

Comparison of "hot Jupiter" exoplanets (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.

References

  1. ^ a b c Hebb, L.; et al. (2010). "WASP-19b: The Shortest Period Transiting Exoplanet Yet Discovered". The Astrophysical Journal. 708 (1): 224–231. arXiv:1001.0403. Bibcode:2010ApJ...708..224H. doi:10.1088/0004-637X/708/1/224. S2CID 119189785.
  2. ^ a b c "2022 Approved Names". nameexoworlds.iau.org. IAU. Retrieved 7 June 2023.
  3. ^ a b c d "Notes for planet WASP-19b". Extrasolar Planets Encyclopaedia. Retrieved 2009-12-10.
  4. ^ a b Abe, L.; Gonçalves, I.; Agabi, A.; Alapini, A.; Guillot, T.; Mékarnia, D.; Rivet, J.-P.; Schmider, F.-X.; Crouzet, N.; Fortney, J.; Pont, F.; Barbieri, M.; Daban, J.-B.; Fanteï-Caujolle, Y.; Gouvret, C.; Bresson, Y.; Roussel, A.; Bonhomme, S.; Robini, A.; Dugué, M.; Bondoux, E.; Péron, S.; Petit, P.-Y.; Szulágyi, J.; Fruth, T.; Erikson, A.; Rauer, H.; Fressin, F.; Valbousquet, F.; et al. (2013). "The secondary eclipses of WASP-19b as seen by the ASTEP 400 telescope from Antarctica". Astronomy & Astrophysics. 553: A49. arXiv:1303.0973. Bibcode:2013A&A...553A..49A. doi:10.1051/0004-6361/201220351. S2CID 119227468.
  5. ^ a b c d Wong, Ian; Benneke, Björn; Shporer, Avi; Fetherolf, Tara; Kane, Stephen R.; Ricker, George R.; Vanderspek, Roland; Seager, Sara; Winn, Joshua N.; Collins, Karen A.; Mireles, Ismael; Morris, Robert; Tenenbaum, Peter; Ting, Eric B.; Rinehart, Stephen; Villaseñor, Jesus Noel (2020). "TESS Phase Curve of the Hot Jupiter WASP-19b". The Astronomical Journal. 159 (3): 104. arXiv:1912.06773. Bibcode:2020AJ....159..104W. doi:10.3847/1538-3881/ab6d6e. S2CID 209376464.
  6. ^ a b c Sedaghati, Elyar; et al. (2017). "Detection of titanium oxide in the atmosphere of a hot Jupiter". Nature. 549 (7671): 238–241. arXiv:1709.04118. Bibcode:2017Natur.549..238S. doi:10.1038/nature23651. PMID 28905896. S2CID 205259502.
  7. ^ Albrecht, Simon; Winn, Joshua N.; Johnson, John A.; Howard, Andrew W.; Marcy, Geoffrey W.; Butler, R. Paul; Arriagada, Pamela; Crane, Jeffrey D.; Shectman, Stephen A.; Thompson, Ian B.; Hirano, Teruyuki; Bakos, Gaspar; Hartman, Joel D. (2012), "Obliquities of Hot Jupiter Host Stars: Evidence for Tidal Interactions and Primordial Misalignments", The Astrophysical Journal, 757 (1): 18, arXiv:1206.6105, Bibcode:2012ApJ...757...18A, doi:10.1088/0004-637X/757/1/18, S2CID 17174530
  8. ^ waspplanets (2019-12-19). "TESS phase curve of WASP-19b". WASP Planets. Retrieved 2020-01-01.
  9. ^ Petrucci, R.; Jofré, E.; Gómez Maqueo Chew, Y.; Hinse, T. C.; Mašek, M.; Tan, T-G; Gómez, M. (2019), "Discarding orbital decay in WASP-19b after one decade of transit observations★†", Monthly Notices of the Royal Astronomical Society, arXiv:1910.11930, doi:10.1093/mnras/stz3034
  10. ^ "List of ExoWorlds 2022". nameexoworlds.iau.org. IAU. 8 August 2022. Retrieved 27 August 2022.
  11. ^ https://www.facebook.com/pages/DrBradTucker/100063510852713
  12. ^ Staff (3 December 2013). "Hubble Traces Subtle Signals of Water on Hazy Worlds". NASA. Retrieved 4 December 2013.
  13. ^ Mandell, Avi M.; et al. (2013). "Exoplanet Transit Spectroscopy Using WFC3: WASP-12 b, WASP-17 b, and WASP-19 b". Astrophysical Journal. 779 (2). 128. arXiv:1310.2949. Bibcode:2013ApJ...779..128M. doi:10.1088/0004-637X/779/2/128. S2CID 52997396.
  14. ^ "Inferno World with Titanium Skies" (Press release). European Southern Observatory. September 13, 2017. Retrieved December 24, 2017.
  15. ^ Sedaghati, Elyar; MacDonald, Ryan J.; Casasayas-Barris, Núria; Hoeijmakers, H Jens; Boffin, Henri M J.; Rodler, Florian; Brahm, Rafael; Jones, Matías; Sánchez-López, Alejandro; Carleo, Ilaria; Figueira, Pedro; Mehner, Andrea; López-Puertas, Manuel (2021), "A spectral survey of WASP-19b with ESPRESSO", Monthly Notices of the Royal Astronomical Society, 505: 435–458, arXiv:2103.12858, doi:10.1093/mnras/stab1164

External links

Media related to WASP-19b at Wikimedia Commons

Constellation of Vela
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