2020

Illustration of photon subrings around a black hole

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An article published in the journal “Science Advances” reports a study on the possibility of obtaining sharp images of the subrings that form the photon ring around a black hole. A team of researchers led by Michael Johnson of of the Center for Astrophysics – Harvard and Smithsonian (CfA) worked on the feat announced almost a year ago with the publication of the photo of the area around the supermassive black hole at the center of the galaxy M87. The researchers think that adding a space telescope to the ones used by the Event Horizon Telescope (EHT) collaboration would allow to obtain the sharpness needed to distinguish one of the subrings, whose characteristics would allow to obtain more precise measurements of the mass of the black hole and more.

Eros Vanzella indicates the Lyman-Alpha emission region measured with the MUSE instrument (Photo courtesy Eros Vanzella / INAF. All rights reserved)

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An article published in the journal “Monthly Notices of the Royal Astronomical Society” reports the discovery of primordial stars that could belong to the so-called Population III, the first generation of stars in the universe. A team of astrophysicists led by Eros Vanzella and Massimo Meneghetti of the Italian National Institute of Astrophysics, Bologna, used data collected with the MUSE instrument mounted on ESO’s VLT and a powerful gravitational lens generated by the galaxy cluster MACS J0416.1-2403, or simply MACS J0416, to obtain magnified images of stars that seem free of metals and composed only of hydrogen, helium and traces of lithium.

Artist's concept of TRAPPIST-1 and its planets (Image NASA/JPL-Caltech)

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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.

Position and distance diagram of the trans-neptunian objects detected

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An article published in “The Astrophysical Journal” presents a catalog of 316 trans-neptunian objects detected by the Dark Energy Survey (DES) during the first four years of operations. A team led by Pedro Bernardinelli analyzed the data collected with a patient work to eliminate the fixed objects and then focused on the transient ones until they obtained the identification of 245 objects already known and 139 that were hitherto unknown. They’re at distances between 30 and more than 90 times the Earth’s from the Sun. Their detection will help to understand their origin and in general the Kuiper belt, where someone thinks that there may be another planet.

Moreux Crater on Mars

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ESA has released new photos of Moreux Crater on the planet Mars taken by the Mars Express space probe’s High Resolution Stereo Camera (HRSC). It’s an impact crater, but shows characteristics that are out of normal, considered the result of erosion caused by glacial processes. Glaciations probably occurred in different periods since the geological traces present in the area suggest that they occurred even in the last millions of years. Another reason for interest in this crater is the presence of dunes inside it, which provide information on the winds blowing in the area.