Xavier Bonfils

Seven hours: that's how long a year lasts on TOI-4552b. It whips around its star faster than some moons orbit Earth. The star is a dim red dwarf, four times smaller than the Sun, but the planet is so close that it receives hundreds of times more heat than we do.

When a planet slips behind the edge of its star, the star backlights the planet's atmosphere, just as a setting sun illuminates clouds on the horizon. This brief moment, lasting only minutes, carries the imprint of the gases through which the starlight has passed.