Water-World Super-Earth Found in Nearby Binary System
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Water-World Super-Earth Found in Nearby Binary System
Astronomers using NASA’s Transiting Exoplanet Survey Satellite (TESS) and the SPIRou spectropolarimeter on the 3.6-m Canada-France-Hawaii telescope have discovered a temperate super-Earth exoplanet orbiting a red dwarf in the binary system TOI-1452.
An artistic rendition of the super-Earth TOI-1452b. Image credit: Benoit Gougeon, Université de Montréal.
The TOI-1452 binary system resides about 100 light-years away in the constellation of Draco.
Also known as TIC 420112589 or 2MASS J19204172+7311434, it consists of two M-dwarf (red dwarf) stars.
The two stars orbit each other once every 1,400 years and are
separated by a small distance — 97 AU (astronomical units), or about 2.5
times the distance between the Sun and Pluto.
The newfound planet circles the primary member of the TOI-1452 system in a temperate orbit that takes 11.1 days.
Named TOI-1452b, the alien world is about 1.7 times larger and 4.8 times more massive than Earth.
“The planet is located at a distance from its star where its
temperature would be neither too hot nor too cold for liquid water to
exist on its surface,” said Université de Montréal Ph.D. student Charles
Cadieux and colleagues.
TOI-1452b is probably rocky like Earth, but its radius, mass, and density suggest a world very different from our own.
“TOI-1452b is one of the best candidates for an ocean planet that we have found to date,” Cadieux said.
“Its radius and mass suggest a much lower density than what one would
expect for a planet that is basically made up of metal and rock, like
Earth.”
According to the astronomers, water may make up 22% of TOI-1452b’s
mass, a proportion similar to that of Jupiter’s moons Ganymede and
Callisto and Saturn’s moons Titan and Enceladus.
“The water world candidate TOI-1452b is a prime target for future
atmospheric characterization with the NASA/ESA/CSA James Webb Space
Telescope, featuring a transmission spectroscopy metric similar to other
well-known temperate small planets such as LHS 1140b and K2-18b,” they said.
“The system is located near Webb’s northern continuous viewing zone,
implying that is can be followed at almost any moment of the year.”
The discovery of TOI-1452b is reported in a paper in the Astronomical Journal.
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Charles Cadieux et al. 2022. TOI-1452b: SPIRou and TESS Reveal a Super-Earth in a Temperate Orbit Transiting an M4 Dwarf. AJ 164, 96; doi: 10.3847/1538-3881/ac7cea