TOI-1338 b

Not to be confused with its star system, TOI-1338.

TOI-1338 b is a gas giant circumbinary exoplanet in the constellation Pictor, orbiting around the binary star system TOI-1338. First identified by then-17-year-old Wolf Cukier, it was the first circumbinary planet discovered by the Transiting Exoplanet Survey Satellite (TESS).^[4] It was discovered on 31 July 2019, and announced 6 January 2020.^[5][6]

TOI-1338 b

Artist's impression of the TOI-1338 b exoplanet.
Discovery
Discovered by	Wolf Cukier
Discovery date	31 July 2019
Detection method	Transiting Exoplanet Survey Satellite
Orbital characteristics
Semi-major axis	0.4607+0.0084 −0.0088 AU[1]
Eccentricity	0.0331+0.0022 −0.0021
Orbital period (sidereal)	95.4001+0.0062 −0.0056 days
Inclination	90.494+0.013 −0.014 °
Star	TOI-1338
Physical characteristics
Mean radius	0.683 RJ[2]
Mass	11.3±2.1 M🜨[2]
Mean density	398 kg/m3[3]

Located 1,318 light years away from Earth, the exoplanet has a radius 6.9 times that of Earth, a mass roughly 12.3 times that of Earth, and a mean density of 0.4 g/cm³ (24.84 lb/ft³).^[3][7] This low density either makes it a super-puff planet, or could indicate that it has a ring system and its true radius is smaller.

Discovery and nomenclature

Wolf Cukier, a 17-year-old attending Scarsdale High School in New York at the time, joined the Goddard Space Flight Center in 2019 to work as a summer intern. While studying data that was flagged as an eclipsing binary (provided by volunteers of the Planet Hunters citizen science project), he found the planet on his third day of interning.^[8][9] Its discovery was announced on 6 January at the 235th American Astronomical Society meeting in Honolulu, Hawaii.^[10] He and 6 other volunteers later co-authored a publication about the planet.^[1] Cukier then attended Princeton University and graduated in 2024.

The acronym TOI stands for "TESS Objects of Interest." In February 2021, a petition was launched calling for the planet to be renamed SOPHIE in honor of late Scottish musician Sophie.^[11][12] The petition was supported by Charli XCX and Caroline Polachek.^[11] It was unsuccessful in officially renaming the planet, however the International Astronomical Union announced that the minor planet 1980 RE1 would be given the permanent name Sophiexeon in June 2021.^[13]

Notes