An article published in “The Astrophysical Journal” reports a study on the orbits of protoplanetary disks in binary systems, where different geometries were found. A team of astronomers led by Ian Czekala of the University of California at Berkeley used the ALMA radio telescope to study star systems in formation around two stars, which in jargon are called circumbinary disks. The conclusion is that the disks that orbit the more compact binary systems share almost the same plane while the disks that orbit the wider binary systems have significantly tilted orbital planes.

An article published in “The Astrophysical Journal” reports a study on the X-ray and ultraviolet (XUV) luminosity of TRAPPIST-1, the ultra-cool dwarf star that became famous after the confirmation that it has a system of 7 rocky planets. A team of researchers used a Markov Chain Monte Carlo method to calculate the radiation received over time by those planets concluding that the star had high levels of X-ray and ultraviolet emissions for several billion years causing its planets significant atmospheric erosion and loss of volatile compounds. The researchers also showed that the free / open source approxposterior software can replicate their analysis much faster than emcee, a software used for that type of calculation. This will help to study other red dwarfs to evaluate the habitability of the planets that are increasingly found orbiting red dwarfs.