NASA’s alien-hunting space telescope TESS has found a planet orbiting a pair of stars more than 1,300 light years from Earth.
The planet is called TOI 1338b and is almost seven times larger than the Earth – somewhere between the size of Saturn and Neptune, according to experts.
The TOI 1338 system lies in the Pictor constellation and it’s lone planet orbits the pair of stars every 93 to 95 days, NASA scientists said.
It’s planet status was confirmed by teenage Wolf Cukier who was working as an intern for NASA after finishing his junior year at Scarsdale High School in New York.
NASA researchers have spotted a planet orbiting two stars for the first time, one a red dwarf and the other just 10 per cent larger than the Sun
The original data came from NASA’s Transiting Exoplanet Survey Satellite (TESS) mission and were flagged as a possible planetary system by members of the public.
TESS captures a new image of a single patch of sky every 30 minutes over a 27 day period – generating thousands of photographs. These are all uploaded to the TESS citizen science website where people can flag possible planet candidates.
Cukier had to manually go through pictures flagged by the public in the hope of spotting any fluctuations that could point to a planet.
It was the first task he was assigned as part of his internship with the space agency.
‘I was looking through the data for everything the volunteers had flagged as an eclipsing binary, a system where two stars circle around each other and from our view eclipse each other every orbit,’ he said.
‘Three days into my internship, I saw a signal. At first I thought it was a stellar eclipse, but the timing was wrong. It turned out to be a planet.’
The two stars in the system, which is about 1,300 light years from Earth, orbit one another every 15 days, NASA experts say.
TOI 1338b orbits in almost exactly the same plane as the stars, so it experiences regular stellar eclipses, according to the research team.
The original data came from NASA’s Transiting Exoplanet Survey Satellite (TESS) mission and were flagged as a possible planetary system by members of the public
Scientists use the observations from TESS to generate graphs of how the brightness of stars change over time, this can be used to detect a planet.
When a planet crosses in front of its star from our perspective – a transit – its passage causes a distinct dip in the star’s brightness, say NASA researchers.
‘Planets orbiting two stars are more difficult to detect than those orbiting one.’
TOI 1338b’s transits are irregular and vary in depth and duration thanks to the orbital motion of its stars, the team confirmed.
TESS is expected to observe hundreds of thousands of binary star systems with an obvious eclipse during its initial two-year mission, so many more of these planets should be waiting for discovery, say NASA researchers
TESS only sees the transits crossing the larger star as the transits of the smaller star are too faint to detect.
‘These are the types of signals that algorithms really struggle with,’ said lead author Veselin Kostov, a research scientist at the SETI Institute and Goddard.
‘The human eye is extremely good at finding patterns in data, especially non-periodic patterns like those we see in transits from these systems.’
This is why Cukier was tasked with manually searching through the images to try to identify any patterns in the light dips.
He initially assumed the transit was a result of the smaller star in the system passing in front of the larger ones as both cause similar dips in brightness when viewed from Earth, but the timing was wrong for it to be the stars alone.
The team from NASA’s Goddard Space Flight Centre used software called eleanor to verify the information in the images.
The software package is is named after Eleanor Arroway, the central character in Carl Sagan’s novel Contact.
TOI 1338b orbits in almost exactly the same plane as the stars, so it experiences regular stellar eclipses, according to the research team
This allowed them to confirm the transits were real and not a result of issues with the pictures or instruments used to capture the pictures.
‘Throughout all of its images, TESS is monitoring millions of stars,’ said co-author Adina Feinstein, a graduate student at the University of Chicago.
‘That’s why our team created eleanor. It’s an accessible way to download, analyze and visualize transit data.
‘We designed it with planets in mind, but other members of the community use it to study stars, asteroids and even galaxies.’
TOI 1338 had already been studied from the ground by radial velocity surveys, which measure motion along our line of sight.
Kostov’s team used this archival data to analyze the system and confirm the planet. Its orbit is stable for at least the next 10 million years.
In the Star Wars universe Tatooine orbits twin stars similar to the Sun. The planet is inhospitable and desert like and was home to Anakin and Luke Skywalker
The orbit’s angle to us, however, changes enough that the planet transit will cease after November 2023 and resume eight years later.
While this might be the first detected planet around two stars, worlds in binary star systems have been part of popular fiction for a long time.
A key planet in the Star Wars universe – Tatooine, the lawless desert world that was home to Luke Skywalker – featured twin stars similar to the Sun.
In Doctor Who, the Time Lord homeworld of Gallifrey orbits a Sun like star and a much smaller White Dwarf.
In the Star Trek universe there are dozens of binary star systems but one of the most famous it the one that plays host to the paradise planet of Risa.
TESS is expected to observe hundreds of thousands of binary star systems with an obvious eclipse during its initial two-year mission, so many more of these planets should be waiting for discovery, say NASA researchers.