The planet WASP-52b is 1.27 times the radius of Jupiter, the largest planet in our Solar System. It is thus much bigger than Earth.
WASP-52b is about half the mass of Jupiter, which means that WASP-52b is much less dense. It is bloated planet, puffed up because it is hotter inside.
The star WASP-52 is smaller than the Sun, at 0.79 times the Sun’s radius. Its spectral type is K2, so it is cooler than the Sun, which is a G2 star.
WASP-52b orbits at a distance of 4.07 million km, taking 1.75 days to go round its orbit.
WASP-52 lies in the constellation of Pegasus. Its coordinates are right ascension 23:13:59.0 and declination +08:45:41. The system is at a distance of 175 parsecs from us.
The brightest stars in the plot have magnitude 1 and the faintest have magnitude 6. WASP-52 has a visual magnitude of 12.0, and so is much fainter than these stars. You would need a telescope to see it.
WASP-52b has been observed with NASA’s Hubble Space Telescope. This observation showed that the planet’s atmosphere is mostly cloudy, though it did also detect the metal sodium.
The host star, WASP-52 has star-spots, just as our sun (left) has sunspots. These are magnetic storms generated by the fierce heat of the Sun bubbling to the surface.
We know that WASP-52 is spotted because, when the planet transits, we sometimes see little bumps in the transit profiles (right). Since star spots are darker, a planet passing over a spot blocks out less light, so we see an upward bump.
The discovery of WASP-52 was announced in a paper led by Guillaume Hébrard of the Institut d’astrophysique de Paris.
For more information visit http://exoplanet.eu/catalog/wasp-52_b/.