Astronomers discover a super-Neptune with the lowest density ever found

There are many planets in the universe, each with different compositions and shapes. This is the case for TOI-1883 b, a super-Neptune discovered in 2024 by some astronomers. Located about 383 light-years from Earth, this exoplanet orbits a red dwarf named TOI-1883 every 4.5 days. However, uncertainties remained regarding its mass.

As a result, a team led by Izuru Fukuda of the University of Tokyo in Japan has decided to observe and study this exoplanet using the Infrared Doppler (IRD) instrument on the Subaru Telescope. As a reminder, this telescope is located in Hawaii and it has seven instruments that can observe the universe across different wavelengths.

Thus, the mass of TOI-1883 b is estimated to be about 13.7 times that of Earth, and its radius is about 5.7 times larger than that of our planet. Therefore, its density is estimated to be only 0.4 g/cm³, which is one of the lowest ever discovered. 

In addition, it could be a puffy exoplanet located extremely close to its star. Indeed, according to astronomers, this celestial object may have migrated toward its star in the past and lost a significant amount of mass due to the ultraviolet radiation.

However, many mysteries still surround the origin of TOI-1883 b. Therefore, further observations and studies will be necessary to better understand this world.