The newly-discovered planets orbit TOI-216, a star about 87% the Sun’s mass and 84% its diameter.

Also known as TIC 55652896 or GAIA DR2 4664811297844004352, the star is about 583 light-years away.

One of the new planets, named TOI-216b, is approximately 8.2 times Earth’s size and 26 times its mass.

It circles its parent star every 17 days at a distance of only 0.13 AU (one-third the distance between the Sun and Mercury).

This means the planet is heated intensely by the star, and has a surface temperature around 675 degrees Fahrenheit (357 degrees Celsius).

The second planet, TOI-216c, is 190 times more massive than the Earth and 11.3 times larger.

It is almost two times farther from the star (0.2 AU) than TOI-216b and has a surface temperature around 435 degrees Fahrenheit (224 degrees Celsius). A year on this planet is 34.6 days long.

The discovery was made using data from NASA’s newest planet hunter, TESS, which was launched in April 2018 to search for transiting planets as small as Earth around the nearest and brightest stars.

“The TOI-216 planetary system displays some close similarities to the Kepler-9 system, but is 1.6 magnitudes brighter,” said lead author Dr. David Kipping of Columbia University and colleagues.

“In both cases, one finds low-density gas giants in a 2:1 mean motion resonance orbiting a Sun-like star at similar periods (20 and 40 days). To a lesser degree, the system also resembles KOI-872.”

A paper reporting this discovery will be published in the Monthly Notices of the Royal Astronomical Society.

Source: Sci News