mini-Neptunes tagged posts

An international team of astronomers has performed follow-up observations of a nearby alien world known as TOI-1685 b. Results of the observations, published May 21 on the pre-print server arXiv, indicate that TOI-1685 b is a hot and rocky alien world with an Earth-like density.

The so-called “super-Earths” are planets more massive than Earth but not exceeding the mass of Neptune...

Study shows super-Earths are not leftovers of mini-Neptunes, challenging our understanding of planetary formation. Mini-Neptunes and super-Earths up to four times the size of our own are the most common exoplanets orbiting stars beyond our solar system. Until now, super-Earths were thought to be the rocky cores of mini-Neptunes whose gassy atmospheres were blown away. In a new study published in The Astrophysical Journal, astronomers from McGill University show that some of these exoplanets never had gaseous atmospheres to begin with, shedding new light on their mysterious origins.

From observations, we know about 30 to 50 percent of host stars have one or the other, and the...

New research suggests that the low density of mini-Neptunes could be explained simply by the presence of a thick layer of water. Many exoplanets known today are ‘super-Earths’, with a radius 1.3 times that of Earth, and ‘mini-Neptunes’, with 2.4 Earth radii. Mini-Neptunes, which are less dense, were long thought to be gas planets, made up of hydrogen and helium.

Now, scientists at the Laboratoire d’Astrophysique de Marseille (CNRS/Aix-Marseille Université/Cnes)(1) have examined a new possibility, namely that the low density of mini-Neptunes could be explained simply by the presence of a thick layer of water that experiences an intense greenhouse effect caused by the irradiation from their host star.

These findings, recently published in The Astrophysical Journal Let...