A long time ago in a galaxy (not so) far, far away …
An international team of astronomers has discovered a rare new multi-planet system that closely resembles the home of Star Wars hero Luke Skywalker, Tatooine.
The system includes a new planet called BEBOP-1c, which comes from the name of the project that discovered it: Binaries Escorted By Orbiting Planets.
Here’s how they made the discovery and why it’s important.
What’s so special about this planet?
One of the most exciting things about BEBOP-1c is that it’s a circumbinary planet.
Unlike planets in our solar system, planets in circumbinary systems revolve around two stars instead of one.
In fact, there are only 12 known circumbinary systems.
Rosemary Mardling from Monash University School of Physics and Astronomy co-authored a study on the system, which was published in Nature Astronomy.
“BEBOP-1c is almost as close as it can be to the two stars,” Dr Mardling says.
“Any closer and it would be kicked out of the system by the binary’s strong gravitational field.”
How did they discover it?
In 2020, a circumbinary planet in the same system named TOI-1338b was discovered using data from NASA’s Transiting Exoplanet Survey Satellite (TESS) space telescope.
But researchers were unsuccessful in determining its most fundamental parameter — its mass.
So the team installed two telescopes in Chile’s Atacama Desert to try to measure this.
But instead, they discovered BEBOP-1c.
It was kept under watch using the Doppler method, also known as the wobble or the radial-velocity method, a technique dependent on measuring how fast stars move.
The telescopes tracking the planet’s journey around its two parent stars were shut down for six months during COVID-19, forcing researchers to wait until 2022 to observe the unrecorded section of its orbit.
Why is it an important discovery?
Even though they are rare, circumbinary planets are important for learning about how planets form, Dr Mardling says.
While only two planets are currently known to orbit the TOI-1338/BEBOP-1 binary system, future observations by the team may reveal more.
“If we are to unravel the mysteries of circumbinary Tatooine-like exo-atmospheres, the BEBOP-1 system may provide a new hope,” researchers wrote in the study.
While researchers have been successful in measuring the mass of BEBOP-1c, they will now try to measure its size.
