Quiet Sunday

13 Aug 2018

At https://phys.org/print452857190.html ... on a quiet Sunday two astronomers in Australia came across a supermassive black hole. It is so big it can chomp up a mass equivalent to our Sun every two days. They found a bright point in the sky, later defined as a high redshift quasar. How they got from that to the hungry monster is not clear from the press release but we may visualise a certain amount of assumption. 

At https://phys.org/print452844585.html ... we have the subject of Chorus Waves. These are electromagnetic waves that when converted to sound are said to resemble the chirping of the Dawn Chorus. They are also known from other cosmic bodies in our solar system. The power of the chorus is one million times more intense on Ganymede (a moon of Jupiter) and 100 times more intense on Europa (another moon of Jupiter) - courtesy of the Galileo spacecraft. Chorus waves are radio waves at low frequencies. Unlike the Earth, Ganymede and Europa orbit inside the gigantic magnetic field of Jupiter (which presumably powers the waves). If any of these waves to escape the vicinity of Ganymede they would be capable of accelerating particles to very high energies.

Meanwhile, at https://phys.org/print452772334.html ... another blow for Dark Matter is the headline. A study in Nature Astronomy (August 2018) has had a relook at mysterious emissions found by the Fermi Large Array Telescope. When first discovered it was thought they might mark the point of annihilation of dark matter particles - central to the theory. It seems it was probably not and it is suggested the emissions came  from thousands of rapidly spinning neutron stars - the so called millisecond pulsars.

Over at https://phys.org/print453108243.html ... students spot a mysterious x-ray source - changing brightness very quickly.