Another 'Hot Jupiter' found – a giant 'inflated' planet orbiting a star bigger than our Sun

Astronomers have discovered an alien world habited by one of the most inflated giant planet which is orbiting a star, 2.4 times larger than our Sun. A giant exoworld that expands in size when its parent star is at the end of its life is called "inflated.” The exoplanet designated KELT-12b was spotted by a team of researchers led by Daniel Stevens of the Ohio State University in the US.

The newly found alien world is orbiting a mildly evolved, 2 billion-year-old star KELT-12 that is about 2.4 times larger than our Sun and has a mass of about 1.59 solar masses.

The planet orbits in just five days and is less massive than Jupiter, having about 0.95 the mass of the solar system's gas giant, 'Phys.org' reported.

However, its radius is much larger than astronomers have expected - about 1.79 Jupiter radii. This relatively large radius, combined with an extremely low density at a level of just 0.21 grammes per cubic centimetre indicates that KELT-12b is an inflated exoplanet.

This inflation process is very often seen in the so-called "hot Jupiters" - gas giant planets similar in characteristics to the solar system's biggest planet, with orbital periods of less than 10 days.