Astronomers have pinpointed 27 promising candidates for circumbinary planets, which are celestial bodies that could potentially orbit two stars, reminiscent of the fictional Tatooine from the Star Wars saga.
These candidates were identified through variations in the timing of eclipses within binary star systems, a process facilitated by NASA’s Transiting Exoplanet Survey Satellite (TESS). However, additional observations are required to ascertain whether these candidates are indeed planets. To date, approximately 18 circumbinary planets have been discovered, alongside over 6,000 planets that orbit single stars.
In a recent publication coinciding with Star Wars Day on May 4th, researchers announced the discovery of around 30 additional candidate planets, located between 650 and 18,000 light years from Earth.
“Astronomy often involves concepts that are not easily visualized… People often envision what a circumbinary planet might look like and the experience of standing on a world with two suns,” stated Ben Monet, an associate professor at the University of New South Wales, in an interview with The Guardian.
It is estimated that more than half of the stars in the universe are part of multiple or binary systems. Astronomers detect circumbinary planets through transits, which occur when a planet moves in front of a star, causing a temporary decrease in the star’s brightness. “This shadow on the star allows us to infer the presence of an orbiting body,” explained Montet.
This phenomenon occurs when the alignment between the planet and its stars is optimal from Earth’s perspective. “There may be many systems we have yet to discover,” he added.
“Finding planets is quite challenging; it’s akin to spotting a candle positioned right next to a bright streetlight,” Montet remarked.
The researchers utilized a technique known as “apsidal precession” to observe the movement between stars that orbit and eclipse one another.
Margo Thornton, the study’s lead author and a PhD candidate at UNSW, noted, “By carefully tracking the timing of these eclipses, we can deduce that additional factors may be influencing the system.”
After ruling out factors such as the stars’ rotation and gravitational forces, the team identified 36 star systems out of 1,590 whose dynamics could only be accounted for by the presence of a third object.
For 27 of these systems, there is a possibility that they are planet-sized. Further investigation into their emitted spectra is necessary to officially classify them as circumbinary planets. “The key question is: what is its mass? Is it a planet, a brown dwarf, or a star?” Thornton explained.
The potential planets identified by the team may range in size from that of Neptune to objects up to ten times the mass of Jupiter, utilizing data from NASA’s TESS, a space telescope dedicated to discovering exoplanets since its launch in 2018.
Dr. Sara Webb, an astrophysicist at Swinburne University of Technology who did not participate in the research, commented that the team’s advanced techniques could be instrumental in uncovering more planet candidates in the future.
According to Dr. Webb, circumbinary planets are likely to exhibit extreme environments that differ significantly from those found in our solar system. She proposed that a Tatooine-like planet could theoretically reside in a habitable zone between two stars, where temperatures are balanced and not extreme. She also noted that when the original Star Wars films were released, the existence of exoplanets had not yet been confirmed, highlighting how concepts initially explored in art and science fiction often later resonate with real scientific findings about the cosmos.
This research was published in the Monthly Notices of the Royal Astronomical Society.
(This article was edited by Seekriti Saha, an intern with The Indian Express.)
