WASP-11b

---

title: "WASP-11b" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["exoplanets-discovered-by-wasp", "exoplanets-discovered-in-2008", "giant-planets", "hot-jupiters", "transiting-exoplanets", "aries-(constellation)", "exoplanets-discovered-by-hatnet"] description: "Extrasolar planet in the constellation Aries" topic_path: "general/exoplanets-discovered-by-wasp" source: "https://en.wikipedia.org/wiki/WASP-11b" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Extrasolar planet in the constellation Aries ::

::data[format=table title="Infobox planet"]

Field	Value
name	WASP-11b/HAT-P-10b
image	Exoplanet Comparison WASP-11-HAT-P-10 b.png
caption	Size comparison of WASP-11b/HAT-P-10b with Jupiter.
discoverer	West et al. (SuperWASP)
Bakos et al. (HATNet)
discovery_site	SAAO
discovered	April 1, 2008 (announced)
September 26, 2008 (preprints)
discovery_method	Transit
apsis	astron
semimajor	0.0439 AU
eccentricity	0
period	3.7224690 ± 0.0000067 d
inclination	88.5 ± 0.6
semi-amplitude	69.1 ± 3.5
star	WASP-11/HAT-P-10
mean_radius	1.045
mass	0.460 ± 0.028
density	498 ±
surface_grav	10.5 m/s2
single_temperature	1030
note	surpress
::

| name = WASP-11b/HAT-P-10b | image = Exoplanet Comparison WASP-11-HAT-P-10 b.png | caption = Size comparison of WASP-11b/HAT-P-10b with Jupiter. | discoverer = West et al. (SuperWASP) Bakos et al. (HATNet) | discovery_site = SAAO | discovered = April 1, 2008 (announced) September 26, 2008 (preprints) | discovery_method = Transit | apsis = astron | semimajor = 0.0439 AU | eccentricity = 0 | period = 3.7224690 ± 0.0000067 d | inclination = 88.5 ± 0.6 | semi-amplitude = 69.1 ± 3.5 | star = WASP-11/HAT-P-10 | mean_radius = 1.045 | mass = 0.460 ± 0.028 | density = 498 ± | surface_grav = 10.5 m/s2 | single_temperature = 1030 | note = surpress WASP-11b/HAT-P-10b or WASP-11Ab/HAT-P-10Ab 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. On 26 September 2008, the HATNet Project's paper describing the planet which they designated HAT-P-10b appeared on the arXiv preprint server. 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.

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. An alternative classification system for hot Jupiters is based on the equilibrium temperature and the planet's Safronov number.The Safronov number is defined as \textstyle \Theta = \frac{1}{2} \left(\frac{\mathrm{Planetary\ escape\ velocity}}{\mathrm{Orbital\ velocity}}\right)^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. In the case of WASP-11b/HAT-P-10b, the equilibrium temperature is 1030 KAssumes the planet has zero albedo. Its secondary transit of the planet behind its star has not yet been observed and so the temperature provided is a hypothetical "equilibrium temperature". 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.

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.

Notes

References

References

1. (2011). "The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets".
2. (5 December 2013). "WASP Planets".
3. Schneider, J.. "Notes for star WASP-11/HAT-P-10".
4. Fortney, J. J.. (2008). "A Unified Theory for the Atmospheres of the Hot and Very Hot Jupiters: Two Classes of Irradiated Atmospheres". [[The Astrophysical Journal]].
5. Hansen, B. M. S.. (2007). "Two Classes of Hot Jupiters". [[The Astrophysical Journal]].
6. [http://www.openexoplanetcatalogue.com/planet/WASP-11%20b/ Open Exoplanet Catalogue WASP-11 20b]
7. (2009). "HAT-P-10b: A Light and Moderately Hot Jupiter Transiting A K Dwarf". The Astrophysical Journal.

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