Astronomy / Astrophysics

Dry ice detected with its spectral data and indication of the area (Image Data: ESA/Rosetta/VIRTIS/INAF-IAPS/OBS DE PARIS-LESIA/DLR; Reprinted with permission from G. Filacchione et al., Science 10.1126/science.aag3161 (2016); context image: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0)

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Two articles published in the journal “Science” describe the discovery of dry ice, meaning frozen carbon dioxide, on the surface of the comet 67P/Churyumov-Gerasimenko. A team of researchers led by Gianrico Filacchione of the Italian National Institute for Astrophysics and another led by Sonia Fornasier the French LESIA-Observatoire de Paris and Université Paris Diderot used the observations conducted with the VIRTIS spectrometer aboard ESA’s Rosetta space probe to find for the first time dry ice on a comet’s nucleus.

The possible origin of Sputnik Planitia and Pluto's reorientation (Image courtesy James Keane)

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Two articles published in the journal “Nature” offer an explanation to the reorientation of the dwarf planet Pluto’s spin axis. The heart of the matter is in the great basin of Sputnik Planitia, formerly known as Sputnik Planum, and it’s appropriate to say it because it’s in the heart-shaped region. According to one of two studies the explanation provides additional clues about the presence of an underground ocean.

Illustration of OGLE-2015-BLG-1319: in grey the data from ground-based telescopes, in blue the data from Swift and in red the data from Spitzer (Image NASA/JPL-Caltech)

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An article published in “Astrophysical Journal” describes the study of a brown dwarf that orbits a K-type star that was possible thanks to a gravitational microlensing event. An international team of astronomers used NASA’s Swift and Spitzer space telescopes to take advantage of that event, cataloged as OGLE-2015-BLG-1319, at a distance from its star that at which few of those objects were found, hence the name brown dwarf desert.

The comet 67P/Churyumov-Gerasimenko with its two-lobed shape (Photo ESA/Rosetta/NAVCAM)

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Two articles to be published in the journal “Astronomy & Astrophysics” describe various aspects of a research on the age of the comet 67P/Churyumov-Gerasimenko. Martin Jutzi and Willy Benz of the University of Bern, Switzerland, together with several colleagues conducted a series of computer simulations to study its two-lobed structure concluding that the collision that gave it its present shape hardly occurred over a billion years ago.

The RX J1615 system (Image ESO, J. de Boer et al.)

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Three articles accepted for publication in the journal “Astronomy and Astrophysics” describe as many research on star systems in formation. The research were conducted by different teams of astronomers but have in common the use of the SPHERE instrument mounted on ESO’s VLT (Very Large Telescope), which revealed details never seen before of protoplanetary discs around the young stars RX J1615, HD 97048 and HD 135344B.