Stars

A solution to the mystery of the origin of long gamma-ray bursts

An article published in the journal “Nature Communications” offers a solution to the problem of the origin of photons that make up a long duration gamma-ray burst. A team of researchers coordinated by the Riken Cluster for Pioneering Research in Japan created a series of simulations based on the Yonetoku relation, an equation devised by Daisuke Yonetoku, one of the authors of the research, which links the peaks of energy and brightness in gamma-ray bursts concluding that their photons originate in the photosphere, the area of ​​a star in which normal light is emitted.

A giant molecular cloud in which massive stars are forming studied with the SOFIA flying telescope

The SOFIA flying telescope was used to study a giant molecular cloud that is a star-forming area cataloged as W51 in order to analyze the newly formed or still forming stars within it. The researchers combined the observations made with SOFIA with those made over time with NASA’s Spitzer and Herschel space telescopes to obtain more complete information on those stars. There was a particular interest in the massive stars and one of them seems really huge, with a mass estimated at about 100 times the Sun’s. If that estimate is confirmed by follow-up observations it’s one of the most massive stars in formation in the Milky Way.

The galaxy MACS0416_Y1 seen by ALMA and Hubble (Image ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope, Tamura, et al.)

An article published in “The Astrophysical Journal” describes a study on the galaxy MACS0416_Y1. A team of researchers led by Professor Yoichi Tamura of the Japanese University of Nagoya used the ALMA radio telescope to observe a galaxy we see as it was about 13.2 billion years ago. The surprising discovery is the considerable amount of interstellar dust present within it, explained by two intense periods of star formation that took place around 300 million and 600 million years after the Big Bang with a quiet phase between them.

A binary system formed by high mass newborn stars

An article published in the journal “Nature Astronomy” describes the first observation of a binary system formed by high mass newborn stars. A team of researchers used the ALMA radio telescope to study a star-forming region cataloged as IRAS07299-1651 where a cloud of gas and dust is collapsing adding materials to two protostars that have similar masses for a total of at least 18 solar masses and must still reach a state of stability. The observations indicate that this pair was born from the division of a single disk of gas and dust and now each of the two protostars is surrounded by its own disk.

Artist's concept of Kepler-62f, an exoplanet orbiting a K-class star (Image NASA Ames/JPL-Caltech/Tim Pyle)

An article published in the “Astrophysical Journal Letters” offers considerations on the possible advantages in the search for biosignatures such as the presence of oxygen and methane on exoplanets orbiting a K-class star, a bit smaller than the Sun. Giada Arney of NASA’s Goddard Space Flight Center tried to find out what those biosignatures and therefore the signs of the presence of life forms on an exoplanet in that kind of system could look like creating a series of computer simulations to understand where to look for traces of oxygen and methane.