| 👁 Image Artist's impression of exoplanet WASP-107b.[1] | |
| Discovery | |
|---|---|
| Discovered by | D. R. Anderson et al. |
| Discovery date | 2017 |
| WASP-South | |
| Orbital characteristics | |
| 0.0566 ± 0.0017 AU (8,470,000 ± 250,000 km)[2] | |
| Eccentricity | 0.09 ± 0.02[3] |
| 5.721487 d [3] | |
| Star | WASP-107 |
| Physical characteristics | |
| 0.96±0.03 RJ[2] | |
| Mass | 0.096±0.005 MJ[2] |
| Temperature | 750 K (477 °C)[4] |
| Atmosphere | |
| Composition by volume | water vapor, helium, sulfur dioxide, ammonia, hydrogen sulfide, carbon monoxide, silicate cloud [5][6] |
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WASP-107b is a super-Neptune exoplanet that orbits the K-type star WASP-107 which is located around 200 light-years away from Earth in the constellation of Virgo.[7]
Its discovery was announced in 2017 by a team led by D. R. Anderson via the WASP-South.[8]
Planetary orbit
[edit]It orbits around WASP-107 at a distance of around 0.05 AU with a eccentricity of 0.09 taking around 5.7 days to complete an orbit around the star. This makes it is about eight times nearer to its star than Mercury is to the Sun.[7] It is in a retrograde orbit, strongly misaligned with the equatorial plane of the parent star. The misalignment angle is equal to 118°+38
−19.[9] WASP-107c follows a highly eccentric and inclined orbit with a period of 1088+15
−16 days.[2]
WASP-107b could not have formed in its current orbit. It likely migrated inward from its birth orbit beyond 1 AU due to interaction with the heavier planet WASP-107c.[2]
Physical characteristics
[edit]WASP-107b is a super-Neptunian ice giant exoplanet that is roughly the size of Jupiter but less than one-tenth of Jupiter's mass, making it one of known lowest density-exoplanets.[2] This is unusual provided that the mean temperature of its upper atmosphere is only 500 °C (932 °F), much lower than that of similarly inflated exoplanets.[4]
Its highly extended and low density atmosphere coupled with transiting a moderately bright orange dwarf star makes it an attractive target for atmospheric characterization via transmission spectroscopy.[10]
Atmosphere
[edit]Helium was discovered in the planet's atmosphere in 2018, making it the first time helium was discovered on an exoplanet.[11] A follow-up observation with Keck in 2020 showed that the helium absorption extends beyond transit-egress.[5] Extreme ultraviolet radiation from the host star is gradually whittling down the planet's atmosphere, forming a comet-like tail 7 times as long as the radius of the planet.[12][13] In November 2023, scientists discovered that its atmosphere contains water (H2O) vapour and sulfur dioxide (SO2). The clouds on this planet are made up of silicates.[14][6] The data, along with the unexpectedly low abundance of methane (CH4), suggests a hotter interior and a more massive core than previously estimated. Tidal heating, caused by the planet's slightly elliptical orbit, is believed to be the source of the extra internal heat.[15]
In September 2024 it was revealed that there is an east-west asymmetry in the atmospheric properties (e.g, climate, cloud structure) of WASP-107b, which previously had not been expected for planet of its type.[4]
See also
[edit]References
[edit]- ^ heic1809 (2 May 2018). "Hubble detects helium in the atmosphere of an exoplanet for the first time". www.spacetelescope.org. Retrieved 4 May 2018.
{{cite web}}: CS1 maint: numeric names: authors list (link) - ^ a b c d e f Piaulet, Caroline; Benneke, Björn; et al. (2021-01-18). "WASP-107b's Density Is Even Lower: A Case Study for the Physics of Planetary Gas Envelope Accretion and Orbital Migration". The Astronomical Journal. 161 (2): 70. arXiv:2011.13444. Bibcode:2021AJ....161...70P. doi:10.3847/1538-3881/abcd3c. ISSN 1538-3881. S2CID 227208673.
- ^ a b Wu, Yunke; Zhang, Zixin; Ma, Xinyue; Chen, Zhangliang; Wang, Wenqin; Liu, Shang-Fei; Yu, Cong; Chen, Dichang; Ma, Bo (2026). "Evidence for a Nonzero Eccentricity Superpuff Exoplanet WASP-107 b Using JWST Occultation Observation". The Astrophysical Journal Letters. 996 (2): L28. arXiv:2601.00640. doi:10.3847/2041-8213/ae2ac8.
- ^ a b c Lea, Robert (2024-09-25). "James Webb Space Telescope finds 'puffball' exoplanet is uniquely lopsided". Space.com. Retrieved 2024-09-28.
- ^ a b Kirk, James; Alam, Munazza K.; Lopez-Morales, Mercedes; Zeng, Li (2020-01-21). "Confirmation of WASP-107b's extended Helium atmosphere with Keck II/NIRSPEC". The Astronomical Journal. 159 (3): 115. arXiv:2001.07667. Bibcode:2020AJ....159..115K. doi:10.3847/1538-3881/ab6e66. S2CID 210838904.
- ^ a b Dyrek, Achrène; Min, Michiel; Decin, Leen; Bouwman, Jeroen; Crouzet, Nicolas; Mollière, Paul; Lagage, Pierre-Olivier; Konings, Thomas; Tremblin, Pascal; Güdel, Manuel; Pye, John; Waters, Rens; Henning, Thomas; Vandenbussche, Bart; Ardevol Martinez, Francisco (2023-11-15). "SO2, silicate clouds, but no CH4 detected in a warm Neptune". Nature. 625 (7993): 51–54. arXiv:2311.12515. doi:10.1038/s41586-023-06849-0. ISSN 0028-0836. PMID 37967578. S2CID 265219725.
- ^ a b Reed, Nola (2 May 2018). "An Exoplanet First! Helium Spotted on Bizarre Comet-Like World". Space.com.
- ^ Anderson, D.R.; Cameron, A. Collier; et al. (August 2017). "The discoveries of WASP-91b, WASP-105b and WASP-107b: Two warm Jupiters and a planet in the transition region between ice giants and gas giants" (PDF). Astronomy & Astrophysics. 604 (A110): A110. arXiv:1701.03776. Bibcode:2017A&A...604A.110A. doi:10.1051/0004-6361/201730439. S2CID 58910823.
- ^ Rubenzahl, Ryan A.; Dai, Fei; Howard, Andrew W.; Chontos, Ashley; Giacalone, Steven; Lubin, Jack; Rosenthal, Lee J.; Isaacson, Howard; Batalha, Natalie M.; Crossfield, Ian J. M.; Dressing, Courtney; Fulton, Benjamin; Huber, Daniel; Kane, Stephen R.; Petigura, Erik A.; Robertson, Paul; Roy, Arpita; Weiss, Lauren M.; Beard, Corey; Hill, Michelle L.; Mayo, Andrew; Mocnik, Teo; Murphy, Joseph M. Akana; Scarsdale, Nicholas (2021), "The TESS–Keck Survey. IV. A Retrograde, Polar Orbit for the Ultra-low-density, Hot Super-Neptune WASP-107b", The Astronomical Journal, 161 (3): 119, arXiv:2101.09371, Bibcode:2021AJ....161..119R, doi:10.3847/1538-3881/abd177, S2CID 231698426
- ^ "First results on the atmosphere of WASP-107b". Wide Angle Search for Planets. September 27, 2017.
- ^ Witze, Alexandra (2 May 2018). "Astronomers spot helium on exoplanet for first time". Nature. doi:10.1038/d41586-018-05052-w.
- ^ waspplanets (2020-01-22). "Helium reveals the extended atmosphere of WASP-107b". WASP Planets. Retrieved 2020-01-22.
- ^ Spake, J. J.; Oklopčić, A.; Hillenbrand, L. A. (2021), "The Posttransit Tail of WASP-107b Observed at 10830 Å", The Astronomical Journal, 162 (6): 284, arXiv:2107.08999, Bibcode:2021AJ....162..284S, doi:10.3847/1538-3881/ac178a, S2CID 236087427
- ^ Greenfieldboyce, Nell (15 November 2023). "Clouds made of sand make for a strange kind of rain on this hot planet". NPR News. Retrieved 16 November 2023.
- ^ "Webb Cracks Case of Inflated Exoplanet - NASA Science". science.nasa.gov. 20 May 2024. Retrieved 2024-05-21.
