The dwarf galaxy ESO 495-21 (Image ESA/Hubble, NASA)

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An image captured by the Hubble space telescope shows the dwarf galaxy ESO 495-21, really small having an estimated total mass of around 10 billion solar masses, about 3% of the Milky Way. The astronomers’ interest in ESO 495-21 is due to the fact that, despite its small size, it’s of the starburst type, which means that it has a fast rate of star formation, and has at its center a supermassive black hole with a mass estimated at at least one million solar masses. It’s a case that could be similar to the first galaxies of the universe and supports the hypothesis that the dwarf galaxy formed around a black hole that already existed before.

Saturn rings sculpted by nearby moons

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An article published in the journal “Science” reports new details on Saturn rings and the moons that orbit embedded in them, in particular Daphnis, in the space inside the Ring A called Keeler Division. A team of researchers used data collected by the Cassini space probe during the last months of its mission to better understand their composition and how the nearby moons sculpt them generating a greater complexity than expected. A second article written by Shigeru Ida comments on this new study.

A solution to the mystery of the formation of the exoplanet CI Tauri b

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An article to be published in “Astrophysical Journal Letters” offers a solution to the mystery of the formation of the exoplanet CI Tauri b, a very young hot Jupiter that contradicts the models that predict that a gas giant is supposed to take at least 10 million years to form. A team of researchers used the IGRINS spectrograph to observe that exoplanet and the data collected suggest that it formed with the mechanism called hot start in jargon in which a gravitational instability is a key element in the quick formation of gas giant planets. Astronomers Christopher Johns-Krull of Rice University and Lisa Prato of the Lowell Observatory, among the authors of the research, presented these conclusions at the 234th meeting of the American Astronomical Society.

The presence of toxic gases could limit the habitability of rocky exoplanets

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An article published in the journal “The Astrophysical Journal” offers a new definition of the habitable zone of ​​a star system where a planet that can accommodate life forms similar to the Earth’s can orbit. A team of researchers coordinated by the University of California – Riverside examined the available data on the atmospheres of exoplanets with orbits in what until now has been considered the habitable zone discovering that in most cases there’s an amount of carbon dioxide and carbon monoxide toxic for complex life forms as we know them. In essence, the new definition significantly reduces the habitable zone.

The NEAR instrument (Photo ESO/ NEAR Collaboration)

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The NEAR (Near Earths in the AlphaCen Region) instrument mounted on the ESO VTL in Chile saw the so-called first light, which means that it made its first observation after being activated. This instrument is designed to detect exoplanets in the Alpha Centauri system, made up of two stars which, together with their farther and smaller companion Proxima, are the closest to the Sun at a distance of about 4.3 light years. ESO collaborated in this project with the Breakthrough Watch program.