Astronomers at the University of Pennsylvania have discovered an exoplanet TOI-3757 b, slightly larger than Jupiter, but three times less massive.
And arXiv.org indicates that scientists discovered this planet by the “transit” method, which involves searching for stars whose brightness curve decreases due to the passage of a large object in their background. The planetary nature of the signal detected in the star TOI-3757, which belongs to a red dwarf of the spectral type M, was confirmed by subsequent follow-up.
The radius of TOI-3757 b is 1.09 times greater than that of Jupiter, and its mass is about 0.268 that of Jupiter. That is, its density is 0.27 grams per cubic centimeter. This makes it the least dense planet orbiting a spectral type M star. The planet orbits its parent star once every 3.44 days at a distance of about 0.038 AU. The planet’s equilibrium temperature is estimated at 759 K.
The parent star TOI-3757, in which the planet orbits, is located about 578 light-years from Earth, has an estimated age of 7.1 billion years and an effective temperature of 3,913 Kelvin. It is 37 percent lighter than the Sun, and contains the lowest metallic content (elements heavier than hydrogen) of all known red dwarfs with gas giants.