January 2020

Artist's concept of Sub-Neptune planet (Image NASA/ESA/G. Bacon (STScI)/L. Kreidberg & J. Bean (U. Chicago)/H. Knutson (Caltech) )

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An article published in “The Astrophysical Journal Letters” offers an explanation of the abundance of sub-Neptune planets discovered compared to gas giants. A team of researchers led by Edwin Kite of the University of Chicago studied the characteristics of these planets offering as an explanation what they called fugacity crisis in reference to the term that measures how much more easily a gas dissolves into a mixture than it would be expected based on pressure. In the case of the sub-Neptune planets, the their atmosphere’s gas dissolve in the ocean of magma that probably covers the surface of their rocky core.

The galaxy AGC 203001 is the most visible thanks to the huge red ring

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An article published in the journal “Monthly Notices of the Royal Astronomical Society” reports the discovery of a giant neutral hydrogen ring surrounding a “quenched galaxy” cataloged as AGC 203001. A team of astronomers from the National Center for Radio Astrophysics (NCRA) in Pune, India, used the Giant Metrewave Radio Telescope (GMRT) to observe that ring, much larger than the galaxy itself with a diameter of about 380,000 light years, four tiems the Milky Way’s. The collaboration of French astronomers allowed a further study with the Canada-France-Hawaii-Telescope (CFHT) in Hawaii, USA, which found no signs of stars associated with the ring, an oddity considering that such a structure seems perfect as a nursery for new stars.

Artist's concept of a blazar (Image courtesy M. Weiss/CfA)

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An article published in the journal “Monthly Notices of the Royal Astronomical Society” reports a study on the blazar CTA 102. A team of researchers used data that cross the electromagnetic spectrum from radio waves to gamma rays detected by a series of space and ground-based telescopes. They allowed to monitor the variability of CTA 102 between 2013 and 2017 and events such as the significant activity of gamma ray emissions between November 2016 and February 2017, with outbursts on four occasions with a peak reached on December 28, 2016.