Astronomy / Astrophysics

The sky around the double star V471 Tauri, visible in low luminosity in the middle of the image (Image ESO/Digitized Sky Survey 2)

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SPHERE (Spectro-Polarimetric High-contrast Exoplanet REsearch) is an instrument built especially to take direct pictures of exoplanets but the first scientific article based on its observations was about the binary system V471 Tauri. A group of astronomers led by Adam Hardy carried out this research, published in the journal “Astrophysical Journal Letters”, explaining why it led to a surprise.

The astronomers expected that there was a brown dwarf orbiting this double star but SPHERE didn’t find anything. It’s a surprising result because the presence of a brown dwarf was by far the most plausible explanation for the strange behavior of V471 Tauri.

Two pictures of Ceres taken by NASA's space probe Dawn (Image NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

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NASA’s Dawn spacecraft is approaching the dwarf planet Ceres. On February 12, 2015, when it was at a distance of about 83,000 kilometers (about 52,000 miles), it took some pictures that show us Ceres with a quality never seen before, allowing us to see its craters. The photos taken previously had puzzled scientists for the presence of some white spots but the new images don’t solve the mystery.

Photo of the comet 67P/Churyumov–Gerasimenko taken by the Rosetta space probe on February 9, 2015 during its approach (Image ESA/Rosetta/NAVCAM)

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Last Saturday, ESA’s Rosetta space probe made a flyby just 6 kilometers (about 4 miles) away from the comet 67P/Churyumov-Gerasimenko, which is becoming more and more active because the approach to the Sun is sublimating its water ice. This maneuver is an important moment in the Rosetta mission for the possible analyzes but also because it starts a new phase in which the probe will move away from the comet for its passage closest to the Sun in August 2015.

The Rosetta space probe’s flyby is the culmination of a series of maneuvers that started on February 4, 2015 when it abandoned the orbit in which he was flying, about 26 kilometers from the comet 67P/Churyumov-Gerasimenko. Initially, Rosetta moved away from the comet until it was 142 kilometers (about 88 miles) away then it moved close again and to reach the minimum distance on February 14.

A comparison of the map of Ligeia Mare on Titan before and after the application of despeckling (Image NASA/JPL-Caltech/ASI)

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Since July 2014, NASA’s space probe Cassini has been accomplishing its mission exploring Saturn and its moons, including Titan. Its SAR (Synthetic Aperture Radar) instrument allowed to map almost half of the surface of this satellite, allowing to know its geological features like never before. Now these surveys can offer even more details thanks to a new technique that improves their quality.

The images created thanks to the Cassini space probe’s SAR are “grainy”, like photographs of limited quality. Scientists must strive to interpret the smaller geological features or to identify changes in images of the same area taken at different times. The new technique called despeckling by its developers is improving the situation.

Map of the polarisation of the Cosmic Microwave Background Radiation (Image ESA and the Planck Collaboration)

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Nearly two years after presenting the best map ever made of the cosmic microwave background radiation, ESA revealed another map created using data collected by the Planck Surveyor space probe between 2009 and 2013. This new map shows the polarization of the cosmic microwave background radiation dating back to the early stages of the universe. It shows that the first stars started forming about 550 million years after the Big Bang, 100 million years later than previously thought.