An article accepted for publication in “The Astrophysical Journal” reports a study on the star R136a1, perhaps the most massive known. A team of researchers pushed the Zorro instrument mounted on the Gemini South telescope to its limits to observe R136a1, or RMC 136a1. The results suggest that it’s less massive than previously estimated, as it was thought to be even more than 300 times the Sun’s mass. It remains a colossus given that the new estimate peaks in probability at 196 times the Sun’s mass. Two “siblings” may also be less massive than previously estimated, as this study estimates the mass of the star R136a2 to be about 151 times the Sun’s and the mass of the star R136a3 to about 155 times the Sun’s. Understanding these huge stars better helps to better predict their end and the chemical elements that will be created at that stage.

An article accepted for publication in “The Astrophysical Journal” reports an analysis of the situation of the star Betelgeuse examining its recovery after what was called the Great Dimming. A team of researchers used a number of instruments including the Hubble Space Telescope and other ground-based and space observatories to reconstruct the history of that event and to examine its consequences. Betelgeuse is returning to what it was a few years ago but not exactly because the colossal coronal mass ejection, confirmed once again by this study, which caused the Great Dimming has also altered stellar cycles that had existed for at least two centuries.

An article accepted for publication in “The Astrophysical Journal Letters” reports the results of the analysis of the detections of the short gamma-ray burst cataloged as GRB 211106A conducted thanks to the ALMA radio telescope. A team of researchers examined the afterglow generated by the interaction with the surrounding gas of the jets that accompany the gamma-ray burst and move at a speed close to the speed of light. This is the first case in which ALMA has been used to examine such an event and other observations were conducted with the VLA and various space telescopes. The resulting dataset covers the various electromagnetic bands and allowed the researchers to conclude that this gamma-ray burst was generated by the merger of two neutron stars.