Category Astronomy/Space

A visualization of a supercomputer simulation of merging black holes sending out gravitational waves. Credit: NASA/C. Henze Read more at: https://phys.org/news/2017-05-uncover-gravitational-characteristics.html#jCp

Monash researchers have identified a new concept – ‘orphan memory’ – which changes the current thinking around gravitational waves. Einstein’s theory of general relativity predicts that cataclysmic cosmic explosions stretch the fabric of spacetime. The stretching of spacetime is called ‘gravitational waves.’ After such an event, spacetime does not return to its original state. It stays stretched out. This effect is called ‘memory.’ The term ‘orphan’ alludes to the fact that the parent wave is not directly detectable.

“These waves could open the way for studying physics currently...

A false-color image map of the gas density in the Musca star-forming filament (the highest densities are shown in red). New theoretical work on the structure of these long filaments proposes several kinds of star-forming zones along the length and successfully reproduces many of the features seen in filaments like this one in Musca. Kainulainen, 2016

Interstellar molecular clouds are often seen to be elongated and “filamentary” in shape, and come in a wide range of sizes. In molecular clouds, where stars form, the filamentary structure is thought to play an important role in star formation as the matter collapses to form protostars...

Artists’ impression of the gas and dust disk around the planet-like object OTS44. First radio observations indicate that OTS44 has formed in the same way as a young star. Credit: Johan Olofsson (U Valparaiso & MPIA)

First radio observations of the lonely, planet-like object OTS44 reveal a dusty protoplanetary disk that is very similar to disks around young stars. This is unexpected, given that models of star and planet formation predict that formation from a collapsing cloud, forming a central object with surrounding disk, should not be possible for such low-mass objects. Apparently, stars and planet-like objects are more similar than previously thought...

Oblique view of the reconnection region. Magnetic field direction is represented by the cyan lines. The color trail represents an electron moving in the field. Color of the particle trail represents a dimensionless speed of the particle, with blue for slow and red for fast. Credit: NASA’s Goddard Space Flight Center/Tom Bridgman

You can’t see them, but swarms of electrons are buzzing through the magnetosphere around Earth. The electrons spiral and dive around the planet in a complex dance dictated by the magnetic and electric fields. When they penetrate into the magnetosphere close enough to Earth, the high-energy electrons can damage satellites in orbit and trigger auroras...