NASA announces the discovery by TESS of a new planet housed in a two-star system. A first for the satellite.
During the 235th meeting of the American Astronomical Union, held a few days ago, NASA presented new discoveries signed by the TESS satellite. The new exoplanet hunter, active since April, has already discovered dozens of new worlds. Until now, however, all have been moving around a star, like the Earth with the Sun.
Then Wolf Cukier, of Scarsdale High School, in the United States, was hired. A NASA intern this summer, his job was to examine variations in the brightness of stars captured by the satellite, uploaded to the citizen science project Planet Hunters TESS.
“I was looking through the data for anything that had been flagged as an eclipse binary. In these systems, two stars rotate around each other, eclipsing each orbit from our point of view, explains the young researcher. About three days after the start of my internship, I spotted a signal from a system called TOI 1338. At first I thought it was a stellar eclipse. But it turned out that it was a planet. “
A world of two stars
This planet evolving around two stars (like Tatooine), since baptized TOI 1338 b, is approximately 6.9 times larger than Earth. The system is located at around 1,300 light years in the Painter’s Constellation.
We also learn that the two stars rotate around each other every 15 days. One is about 10% more massive than the Sun, while the other is only a third of its mass.
The two stars are not on the same orbital plane, the transits of TOI 1338 b are also irregular (between 93 and 95 days) and vary in depth.
In addition, it should be noted that TESS only spotted the passages of the planet in front of the largest star. The transits operated in front of the smallest were indeed too weak to be detected.
In other words, without the young intern, this two-star planet could not have been detected. “Algorithms are really struggling with this type of signal, “says Veselin Kostov, researcher at the SETI Institute. The human eye is extremely good at detecting non-periodic patterns like the ones we see in the transits of these systems.”
This new discovery brings to 13 the number of such systems discovered by NASA. The other 12 are credited to the Kepler telescope, now retired. But TESS should still operate for at least two years. So he has not said his last word.