November 2019

An investigation on multiple star systems shows that many of them host planets

An article published in the journal “Monthly Notices of the Royal Astronomical Society” reports an analysis of data collected by ESA’s Gaia space probe in search for exoplanets in multiple systems. Dr. Markus Mugrauer of the University of Jena, Germany, examined over 1,300 stars hosting exoplanets in a radius of about 1,600 light years from Earth to determine which of them had one or even more companions. The result is that over 200 of them are multiple systems, in one case even a quadruple one, in which the companions are above all red dwarfs but in eight cases there’s a white dwarf as a companion. This is the confirmation that multiple systems with exoplanets are not an exception and that exoplanets can survive the death of one of the stars.

Asteroid Ryugu (Photo courtesy JAXA, Chiba Institute of Technology, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Meiji University, University of Aizu, AIST)

The Japanese space agency JAXA has confirmed that its Hayabusa 2 space probe has left asteroid Ryugu, reached on June 27, 2018. Until November 19 it will keep on taking pictures of Ryugu, a limit due to the fact that subsequently a maneuver needed to use its ion engine will lead it to turn into a position from which it will no longer have the asteroid in its camera’s view. Until that day, it will be possible to send a farewell message to Ryugu via Twitter or even letters and postcards to JAXA. Hayabusa 2 is scheduled to return near the Earth with its samples near the end of 2020.

Oxygen spikes in Mars atmosphere are a new mystery

An article published in the “Journal of Geophysical Research: Planets” reports an analysis of the composition of the atmosphere of the planet Mars based on data collected by NASA’s Mars Rover Curiosity. A team of researchers led by Melissa Trainer of NASA’s Goddard Space Center confirmed the presence of various gases already known with seasonal variations due to carbon dioxide’s freezing and evaporation. A surprise came from the detection of a remarkable growth of oxygen in spring and its drop back to the previous levels in fall. This is a new mystery added to that of the presence of methane on the red planet.

60 Starlink satellites blasting off atop a Falcon 9 rocket (Image courtesy SpaceX)

A little while ago 60 satellites of the Starlink constellation were launched on a Falcon 9 rocket from Cape Canaveral. After about an hour they were successfully deployed into their orbit at an altitude of about 280 kilometers all together and then started slowly disperse. This is SpaceX’s second mission to put the Starlink constellation into orbit to provide a global Internet connection coverage.

The image of an ancient galaxy multiplied by a gravitational lens

An article published in the journal “Science” reports a study of a galaxy nicknamed Sunburst Arc observed through a gravitational lensing effect that leads to multiplying its image obtaining at least 12 distorted copies in four large arcs. The Hubble Space Telescope detected the light from that galaxy, about 11 billion light years from Earth, thanks to that effect, which also made it between 10 and 30 times brighter. Studying such an ancient galaxy allows to gather information on the early universe and on what’s called the epoch of reionization.