WASP-76b is a Hot Jupiter exoplanet in the constellation Pisces. Discovered on October 21, 2013, it orbits an F-type main-sequence star BD+01 316 (WASP-76). Its mass is 0.92 times the mass of Jupiter.[4][5]

WASP-76 b (2020).png
Artistic image of WASP-76b (based on 2020 data)
Discovered byR.G. West et al. (SuperWASP)[1]
Discovery dateOctober 21, 2013
Transit (including secondary eclipses)
Orbital characteristics
0.033±0.0005 AU
1.809886±0.000001[2] d
Physical characteristics
Mean radius
1.83±0.06 RJ
Mass0.92±0.03 MJ
Temperature2500±200 K[3]
An artist's illustration showing WASP-76b during its night hours.

The planet's equilibrium temperature is 2,190 K (1,920 °C; 3,480 °F), and its measured day-side temperature is hotter at 2,500 ± 200 K (2,227 ± 200 °C; 4,040 ± 360 °F).[3]

Studies suggest that WASP-76b is the only planet in its star system.[6]

Data from the Hubble and Spitzer Space Telescopes indicates the presence of titanium oxide and traces of water in the planet's atmosphere.[7] Higher-resolution spectra have featured ionized Li, Na, Mg, Ca, Mn, K, and Fe, but no ionized Ti, Cr, Ni, or molecular oxides of Ti, V, or Zr were found.[8] The presence of calcium was confirmed in 2021.[9][10]

The atmosphere of WASP-76b is cloudy and primarily grey, with a significant amount of thermal incandescence.[11]

Iron rain speculationEdit

In March 2020, initial spectroscopic findings indicated the presence of neutral iron. Therefore, it was speculated that if the temperature on the planet could reach 2,400 °C (2,700 K; 4,400 °F) (hot enough to vaporize neutral iron) and cold enough to condense the vapor to 1,400 °C (1,700 K; 2,600 °F), the iron could rain down like a liquid.[12]

In May 2020, the Hubble Space Telescope discovered that the light from a stellar companion distorted the previous spectrum of WASP-76b. Using data from a current, up-to-date spectrum, we have an updated atmospheric model; cloudy hydrogen-helium envelope, non-detection of previously reported neutral iron (including "iron rain"[13]), and only upper limits on oxides of titanium and vanadium.[11] By 2021, the controversy was resolved by demonstrating that the tentative iron condensation signal may also appear due to the temperature asymmetry between leading and trailing limbs. However, existing data does not allow distinguishing between the two scenarios.[14]

Planetary atmospheric circulation models for WASP-76b suggest dense cloud layers formed of aluminum oxide, neutral iron, or magnesium orthosilicate, but no significant nightside condensation of iron.[15]

See alsoEdit


  1. ^ West, R. G.; Hellier, C.; et al. (January 8, 2016). "Three irradiated and bloated hot Jupiters". Astronomy & Astrophysics. 585: A126. arXiv:1310.5607. doi:10.1051/0004-6361/201527276. S2CID 54746373.
  2. ^ "Planet WASP-76 b". exoplanet.eu. March 7, 2022. Archived from the original on April 30, 2022. Retrieved May 24, 2022.
  3. ^ a b Zhou, G.; Bayliss, D. D. R.; et al. (December 11, 2015) [October 16, 2015]. "Secondary eclipse observations for seven hot-Jupiters from the Anglo-Australian Telescope". Monthly Notices of the Royal Astronomical Society. 454 (3): 3002–3019. arXiv:1509.04147. Bibcode:2015MNRAS.454.3002Z. doi:10.1093/mnras/stv2138. S2CID 84835437. Retrieved March 21, 2022.
  4. ^ "WASP-76 b". Exoplanet Exploration: Planets Beyond our Solar System. NASA. n.d. Retrieved March 21, 2022.{{cite web}}: CS1 maint: url-status (link)
  5. ^ Ehrenreich, David; et al. (March 11, 2020). "ESO Telescope Observes Exoplanet Where It Rains Iron". European Southern Observatory. Retrieved March 21, 2022.{{cite web}}: CS1 maint: url-status (link)
  6. ^ Reuters (March 11, 2020). "On a faraway planet, it's cloudy with a chance of liquid iron rain". NBC News. Retrieved May 3, 2020.
  7. ^ Fu, Guangwei; Deming, Drake; et al. (August 17, 2021). "The Hubble PanCET Program: Transit and Eclipse Spectroscopy of the Strongly Irradiated Giant Exoplanet WASP-76b". The Astronomical Journal. 162 (3): 108. arXiv:2005.02568. doi:10.3847/1538-3881/ac1200. ISSN 0004-6256. Retrieved May 24, 2022.{{cite journal}}: CS1 maint: url-status (link)
  8. ^ Tabernero, H. M.; Osorio, M. R. Zapatero; et al. (February 19, 2021). "ESPRESSO high resolution transmission spectroscopy of WASP-76b". Astronomy & Astrophysics. 646. 17. arXiv:2011.12197. doi:10.1051/0004-6361/202039511. ISSN 0004-6361. Retrieved May 24, 2022.{{cite journal}}: CS1 maint: url-status (link)
  9. ^ Casasayas-Barris, N.; Orell-Miquel, J.; et al. (October 27, 2021). "CARMENES detection of the Ca II infrared triplet and possible evidence of He I in the atmosphere of WASP-76b". Astronomy & Astrophysics. 654. 20. arXiv:2109.00059. doi:10.1051/0004-6361/202141669. ISSN 0004-6361. Retrieved May 24, 2022.{{cite journal}}: CS1 maint: url-status (link)
  10. ^ Deibert, Emily K.; de Mooij, Ernst J. W.; et al. (September 28, 2021). "Detection of Ionized Calcium in the Atmosphere of the Ultra-hot Jupiter WASP-76b". The Astrophysical Journal Letters. 919 (2). arXiv:2109.04373. doi:10.3847/2041-8213/ac2513. ISSN 2041-8205. Retrieved May 24, 2022.{{cite journal}}: CS1 maint: url-status (link)
  11. ^ a b Edwards, Billy; Changeat, Quentin; et al. (June 9, 2020). "ARES I: WASP-76 b, A Tale of Two HST Spectra*". The Astronomical Journal. 160 (1): 8. arXiv:2005.02374. Bibcode:2020AJ....160....8E. doi:10.3847/1538-3881/ab9225. S2CID 218502668.
  12. ^ Amos, Jonathan (March 11, 2020). "Wasp-76b: The exotic inferno planet where it 'rains iron'". BBC News. Retrieved May 3, 2020.{{cite news}}: CS1 maint: url-status (link)
  13. ^ Lothringer, Joshua D.; Fu, Guangwei; et al. (July 21, 2020). "UV Exoplanet Transmission Spectral Features as Probes of Metals and Rainout". The Astrophysical Journal. 898 (1): L14. arXiv:2005.02528. Bibcode:2020ApJ...898L..14L. doi:10.3847/2041-8213/aba265. S2CID 218516764. Retrieved May 24, 2022.{{cite journal}}: CS1 maint: url-status (link)
  14. ^ Wardenier, Joost P; Parmentier, Vivien; et al. (June 26, 2021). "Decomposing the iron cross-correlation signal of the ultra-hot Jupiter WASP-76b in transmission using 3D Monte Carlo radiative transfer". Monthly Notices of the Royal Astronomical Society. 506 (1): 1258–1283. arXiv:2105.11034. doi:10.1093/mnras/stab1797. ISSN 0035-8711. Retrieved May 24, 2022.{{cite journal}}: CS1 maint: url-status (link)
  15. ^ Savel, Arjun B.; Kempton, Eliza M.-R.; et al. (February 15, 2022). "No Umbrella Needed: Confronting the Hypothesis of Iron Rain on WASP-76b with Post-processed General Circulation Models". The Astrophysical Journal. 926 (1): 85. arXiv:2109.00163. doi:10.3847/1538-4357/ac423f. ISSN 0004-637X. Retrieved May 24, 2022.{{cite journal}}: CS1 maint: url-status (link)