WASP-1b

WASP-1b is an extrasolar planet orbiting the star WASP-1 located 1,300 light-years away in the constellation Andromeda.

WASP-1b

Size comparison of WASP-1b with Jupiter
Discovery
Discovered by	Cameron et al. (SuperWASP and SOPHIE)  South Africa and  France
Discovery site	SAAO
Discovery date	September 25, 2006
Detection method	Transit
Orbital characteristics
Semi-major axis	0.0382 (± 0.0013) AU
Eccentricity	0
Orbital period (sidereal)	2.5199464 (± 8e-07) d
Inclination	88.65 (± 0.55)
Star	WASP-1
Physical characteristics
Mean radius	1.484 +0.06 −0.09 RJ
Mass	0.86 ± 0.07 MJ
Mean density	0.476 g/cm3[citation needed]
Surface gravity	12.5 m/s2 (41 ft/s2) 1.27 g
Temperature	1,800 K

Orbit and mass

The radial velocity trend of WASP-1, caused by the presence of WASP-1 b

The planet's mass and radius indicate that it is a gas giant with a similar bulk composition to Jupiter. Unlike Jupiter, but similar to many other planets detected around other stars, WASP-1b is located very close to its star, and belongs to the class of planets known as hot Jupiters.

WASP-1 b was discovered via the transit method by SuperWASP, for which the star and planet are named. Follow-up radial velocity measurements confirmed the presence of an unseen companion, and allowed for the mass of WASP-1 b to be determined.^[1]

In 2018, it was discovered via observations of the Rossiter-McLaughlin effect that the orbit of WASP-1b is strongly misaligned with rotational axis of the star by 79.0^+4.3
_−4.5 degrees, making it a nearly "polar" orbit.^[2]

See also

• HD 209458 b
• WASP-2b