WASP-11b/HAT-P-10b or WASP-11Ab/HAT-P-10Ab^[3] is an extrasolar planet discovered in 2008. The discovery was announced (under the designation WASP-11b) by press release by the SuperWASP project in April 2008 along with planets WASP-6b through to WASP-15b, however at this stage more data was needed to confirm the parameters of the planets and the coordinates were not given.^[4] On 26 September 2008, the HATNet Project's paper describing the planet which they designated HAT-P-10b appeared on the arXiv preprint server.^[1] The SuperWASP team's paper appeared as a preprint on the Extrasolar Planets Encyclopaedia on the same day, confirming that the two objects (WASP-11b and HAT-P-10b) were in fact the same, and the teams agreed to use the combined designation.^[2]

The planet had the third lowest insolation of the known transiting planets at the time of the discovery (prior to this, Gliese 436 b and HD 17156 b were known to have lower insolation). The temperature implies it falls into the pL class of hot Jupiters: planets which lack significant quantities of titanium(II) oxide and vanadium(II) oxide in their atmospheres and do not have temperature inversions.^[5] An alternative classification system for hot Jupiters is based on the equilibrium temperature and the planet's Safronov number.^{[note 2]} In this scheme, for a given temperature, class I planets have high Safronov numbers and tend to be in orbit around cooler host stars, while class II planets have lower Safronov numbers.^[6] In the case of WASP-11b/HAT-P-10b, the equilibrium temperature is 1030 K^{[note 1]} and the Safronov number is 0.047±0.003, which means it is located close to the dividing line between the class I and class II planets.^[1]

The planet is in a binary star system, the second star is WASP-11 B, with a mass 0.34 ± 0.05 of the Sun and a temperature of 3483 ± 43 K.^[7]

• OGLE-TR-111b