The discovery was made by a team using a technique called apsidal precession, which detects subtle wobbles in binary star systems as they orbit and eclipse each other. Analyzing data from NASA's Transiting Exoplanet Survey Satellite (TESS), researchers examined 1,590 eclipsing binaries and identified 36 systems where the behavior suggested a third body. For 27 of those, the third object could be planet mass.
"If we monitor the exact timing of these eclipses... that can tell us that there's something else going on in the system," said lead author Margo Thornton, a PhD candidate at the University of New South Wales.
There are many things in astronomy that aren't very tangible. But thanks to the famous Tatooine sunset scene in the first Star Wars film, everyone has a picture of what a circumbinary planet looks like and what would it mean to stand on a planet with two suns.
The candidate planets lie between 650 and 18,000 light-years from Earth and range in size from Neptune-like to about ten times Jupiter's mass. More than half of stars in the universe exist in binary systems, yet most known planets orbit single stars. Further observations of their spectra are needed to confirm that they are indeed planets rather than brown dwarfs or small stars.
"There are many things in astronomy that aren't very tangible. But thanks to the famous Tatooine sunset scene in the first Star Wars film, everyone has a picture of what a circumbinary planet looks like," said senior author Ben Montet, also at UNSW.
We're missing lots of systems, potentially.
The exact masses and orbital parameters of the candidates remain uncertain, and astronomers do not yet know how many will ultimately be confirmed. Montet added, "We're missing lots of systems, potentially."
Planets are hard to find. It's like trying to see a candle right next to a big street light.
If we monitor the exact timing of these eclipses... that can tell us that there's something else going on in the system.
For 27 of those objects, it is possible that they are planet mass. It's just a matter of: what is the mass of it? Is it a planet? Is it a brown dwarf? Is it a star?