Five new 'hot Jupiters' discovered

London, Feb 18: Scientists have discovered five new Jupiter-like planets that are similar in characteristics to our solar system's biggest planet and orbit very close to their host stars.

Researchers from Keele University in UK used the Wide Angle Search for Planets-South (WASP-South) instrument — an array of eight cameras observing selected regions of the southern sky, to study five stars showing planet-like transits in their light curve.

The newly discovered planets were designated WASP-119 b, WASP-124 b, WASP-126 b, WASP-129 b and WASP-133 b, 'Phys.org' reported.

The orbital periods of the planets vary from 2.17 to 5.75 days, and their masses range from 0.3 to 1.2 the mass of Jupiter, with radii between one to 1.5 Jupiter radius, researchers said. WASP-119 b - which has a mass of 1.2 of the mass of Jupiter, and an orbital period of 2.5 days - is a typical hot Jupiter.

Its host star has a similar mass to the Sun's but appears to be much older based on its effective temperature and density.

WASP-124 b, less massive than Jupiter (0.6 Jupiter masses), has orbital period of 3.4 days and a much younger parent star. WASP-126 b is the lowest-mass world found by researchers. Its low surface gravity and a bright host star make the planet a good target for transmission spectroscopy.

"WASP-126b is the most interesting because it orbits the brightest star of the five. This means it can be a target for atmospheric characterisation, deducing the composition and nature of the atmosphere from detailed study, for example with the Hubble Space Telescope or the forthcoming James Webb Space Telescope," said Coel Hellier from Keele University.

WASP-129 b, similar in size to Jupiter, has the longest orbital period. Its surface gravity is also high compared to other known 'hot Jupiters', researchers said.

WASP-133 b has the shortest orbital period of the exoplanets detected by researchers. It is slightly bigger than the solar system's most massive planet (1.2 of Jupiter's mass and 1.2 of its radius). The findings were published in the arXiv journal.

PTI