The discovery, co-authored by Dr Rosemary Mardling, is rare because “BEBOP-1c” is one of two planets in a single system orbiting two suns, a phenomenon known as a circumbinary system.

“We are aware of 12 circumbinary systems so far, and this is only the second one that has more than one planet,” said Dr David Martin, a co-author of the paper who is a former student of Dr Mardling’s.

The first planet in the system, TOI-1338b, was discovered in 2020 as it passed in front of the larger of the two stars several times, and the team tried to measure its mass by installing cutting-edge equipment on two telescopes in Chile.

“The orbital period of BEBOP-1c is 215 days, and its mass is 65 times that of Earth, which is about five times less than Jupiter’s mass,” said Monash University.

“This was a challenging system to confirm because telescopes in Chile were closed for six months because of the COVID pandemic during a crucial part of the planet’s journey around its two parent stars. This particular section of the orbit could only be observed again last year, enabling the research team to confirm their discovery.

“While only two planets are currently known to orbit the TOI-1338/BEBOP-1 binary system, future observations by the team may reveal more. Even though they are rare, circumbinary planets are important for learning about how planets form.”