Australian astrophysicists discover giant planet

The Toowoomba-based team from the University of Southern Queensland confirmed the discovery using five ­robotic telescopes.

Astrophysicists Brett Addison, left, and Jonty Horner. Picture: USQ

An international team led by Queensland researchers has discovered a giant planet orbiting a distant star in an Australian-first for astrophysics.

The gaseous “exoplanet” is about 250 light years away with a mass 40 times that of Earth.

Dubbed TOI-257b, it transits a bright white star every 18 days.

The Toowoomba-based team from the University of Southern Queensland confirmed the discovery using five ­robotic telescopes at its Mount Kent observatory near Greenmount, 32km south of Toowoomba.

USQ astrophysicist Brett Addi­son said the discovery marked the first Australia-led confirmation of a planet detected through NASA’s Transiting Exoplanet Survey Satellite. It is the 37th planet to be discovered under the program.

He said TOI-257b was an ­example of what astronomers called sub-Saturns, which are larger than Neptune and smaller than Saturn and absent from the solar system. “The universe is a quirky and diverse place, with broad classes of planet such as sub-Saturns, super-Earths and mini-­Neptunes that we don’t have here at home.”

His colleague, Jonty Horner, said while the team had confirmed existence of the planet, no one has yet seen a clear image of the distant world.

“We aren’t seeing the planet itself but as we detect how the star behaves and wobbles and winks, we know the planet is there,” Dr Horner said. “It’s a bit like you holding your hand up and knowing there are bones ­inside but you can’t see them ­because your skin is in the way.”