April 2019

The black hole V404 Cygni swings like a spinning top

An article published in the journal “Nature” reports the observation of a jet of materials emitted by the black hole V404 Cygni which changed orientation in no more than a few hours. A team led by James Miller-Jones of the Curtin University node of the International Center for Radio Astronomy Research (ICRAR), Australia, used the Very Long Baseline Array radio telescopes to study the area around the black hole during one of its periodic bursts of considerable intensity. This made it possible to observe for the first time jets of materials changing orientation in a few hours or even minutes.

The position of quasars varies over time

An article published in the journal “Monthly Notices of the Royal Astronomical Society” reports evidence that the position of quasars is not fixed. A team of astrophysicists from the Moscow Institute of Physics and Technology combined global observations of 40 quasars between 1994 and 2016 for this study. Based on the fact that the apparent positions of quasars change according to the frequency of the radiation used to observe them, the researchers wanted to verify if that effect could vary over time. Quasars are used as cosmic reference points, knowing their exact location can increase their reliability.

The extent of the expansion of the universe is increasingly precise and stresses the discrepancy between the measurements

An article published in “The Astrophysical Journal” reports a new measurement of the expansion of the universe, which is approximately 9% faster than the estimates made by studying the early universe. A team of astronomers led by Nobel laureate Adam Riess combined observations made with the Hubble Space Telescope of 70 variable stars called Cepheid variables used for measurements with others conducted by the Araucaria project to obtain extremely precise measurements of their brightness. The discrepancy between the measurements of the expansion of the near universe and those of the early universe remains and it’s important to improve the measurements to obtain clues to the origin of the discrepancy.

A possible earthquake detected on Mars by the InSight lander

NASA has announced that its InSight lander detected what’s probably an earthquake on the planet Mars. What was nicknamed marsquake is a small earthquake that on Earth would be recorded with a magnitude of 2-2.5 and it’s only thanks to an instrument called SEIS designed for that purpose that it was detected on Mars on April 6, 2019. We’re at the beginning of Martian seismology therefore the data will be studied to confirm that it was indeed an earthquake and if that’s the case it will be the first one.

A measurement of the temperatures on the surface of comet 67P/Churyumov-Gerasimenko

An article published in the journal “Nature Astronomy” reports a series of measurements of the temperature of comet 67P/Churyumov-Gerasimenko’s nucleus obtained thanks to ESA’s Rosetta space probe’s VIRTIS instrument. A team of researchers led by Federico Tosi of the National Institute of Astrophysics’ Space Astrophysics and Planetology Institute in Rome, Italy, used the infrared images captured by VIRTIS to generate thermal maps from which they obtained the temperatures reconstructing the daily and seasonal variations but also the ones related to its morphological characteristics and the chemical-physical characteristics of the top surface layer.