"Marshmallow" planet found near a cold star. She shouldn't be there

A gas giant exoplanet with the density of a marshmallow has been found in orbit around a cool red dwarf.

Astronomers used a set of instrumentsincluding the NEID radial velocity instrument on the 3.5-meter WIYN telescope at Kitt Peak National Observatory in the United States. The planet was named TOI-3757 b and is the fluffiest gas giant ever found around stars of this type.

An unusual planet similar to Jupiter rotatesin orbit around a cool red dwarf star. It is located approximately 580 light years from Earth in the constellation Auriga. It has the lowest density, resembling marshmallow.

Red dwarfs are the smallest and faintestrepresentatives of main sequence stars. They convert hydrogen into helium in their nuclei at a constant rate. Even though red dwarfs are “cool” compared to stars like our Sun, they are very active and emit powerful flares that can strip a planet of its atmosphere. Such star systems were thought to be inhospitable places for such a thin, “marshmallow” planet to form.

Scientists have suggested that ultra-low densityTOI-3757 b was the result of two factors. Perhaps it's in her core. The star TOI-3757 has a low content of heavy elements compared to other M-dwarfs, and this influenced the formation of a rocky core, which affected the overall density of the planet.

Astronomers also suggested that to the formationThe “marshmallow” planet was driven by its orbit, which is tentatively believed to be slightly elliptical. Due to its periodic approach, it can heat up and its atmosphere inflate.