An article published in “The Astrophysical Journal Letters” reports a study on the exoplanet GJ 367 b, or Gliese 367 b, formally known by the name Tahay, which concludes that its core is composed almost entirely of iron for a density that is almost twice the Earth’s. The researchers also announced the discovery of two more planets in the system of the star GJ 367, formally known as Añañuca, which may be super-Earths.

Just over 30 light-years from Earth, Añañuca is a red dwarf with a mass and size just under half of the Sun’s. Observations began in 2019 with NASA’s TESS space telescope and in 2021 the data collected led to the exploration of the possibility that a planet orbited very close to this star, subsequently confirmed with other instruments. Tahay’s roughly 7.7-hour year is the shortest in the cosmic neighborhood, one reason for interest and worthy of its own name.

An article published in the journal “Astronomy & Astrophysics” reports the discovery of an object that could be a gas giant planet or a brown dwarf in the HIP 81208 system. A team of researchers analyzed data from the archive of the observations conducted with the SPHERE instrument mounted on the VLT in Chile discovering an object that was cataloged as HIP 81208 Cb orbiting the smaller of the two stars in this binary system. A brown dwarf was discovered around the more massive star together with the smaller and more distant star in an analysis also published some time ago in an article in “Astronomy & Astrophysics”. The new discovery makes HIP 81208 a so-called hierarchical quadruple system, the first of its kind discovered using a direct imaging system.

An article published in the “Astrophysical Journal Letters” reports the discovery of two exoplanets orbiting the star TOI-4600 of which the outermost is the one with the longest year discovered so far. A team of researchers used observations conducted with NASA’s TESS space telescope to find traces of these two gas exoplanets. Other ground-based observatories were used to confirm the existence of these two exoplanets and obtain more information about them. TOI-4600 b has a year of nearly 83 Earth days, a bit shorter than Mercury’s, while TOI-4600 c has a year of nearly 483 days, the longest of all known exoplanets. This is a useful discovery to understand what other planetary systems are like because exoplanets close to their stars are much easier to discover while we still know very little about the ones far from their stars.