Category Astronomy/Space

Sun-like stars rotate differentially, with the equator rotating faster than the higher latitudes. The blue arrows in the figure represent rotation speed. Differential rotation is thought to be an essential ingredient for generating magnetic activity and starspots. Credit: MPI for Solar System Research/MarkGarlick.com

Equators of Sun-like stars rotate up to two and a half times as fast as higher latitudes. Scientists have measured the differential rotation on Sun-like stars for the first time, and their findings challenge current science on how stars rotate. Until now, little was known about the precise rotational patterns of Sun-like stars, only that the equator spins faster than at higher latitudes, similar to the Sun.

Scientists at the NYU Abu Dhabi Center for Space Science used observat...

Artist’s impression of a perturbation in the velocities of stars in our Galaxy, the Milky Way, that was revealed by ESA’s star mapping mission, Gaia. Credit: ESA, CC BY-SA 3.0 IGO

ESA’s star mapping mission, Gaia, has shown our Milky Way galaxy is still enduring the effects of a near collision that set millions of stars moving like ripples on a pond. The close encounter likely took place sometime in the past 300-900 million years. It was discovered because of the pattern of movement it has given to stars in the Milky Way disc – one of the major components of our Galaxy.

The pattern was revealed because Gaia not only accurately measures the positions of more than a billion stars but also precisely measures their velocities on the plane of the sky...

This is the characteristic disc structure from the simulation of a misaligned disc around a spinning black hole. Credit: K. Pounds et al. / University of Leicester

Astronomers report the first detection of matter falling into a black hole at 30% of the speed of light, located in the center of the billion-light year distant galaxy PG211+143. The team used data from the European Space Agency’s X-ray observatory XMM-Newton to observe the black hole.

A UK team of astronomers report the first detection of matter falling into a black hole at 30% of the speed of light, located in the centre of the billion-light year distant galaxy PG211+143...

Image from the DCBH simulation shows density (left) and temperature (right) of an early galaxy. Supernovae shock waves can be seen expanding from the center, disrupting and heating the galaxy.
Credit: Georgia Tech

A simulation has suggested what astronomers should look for if they search the skies for a direct collapse black hole in its early stages. Black holes form when stars die, allowing the matter in them to collapse into an extremely dense object from which not even light can escape. Astronomers theorize that massive black holes could also form at the birth of a galaxy, but so far nobody has been able to look far enough back in time to observe the conditions creating these direct collapse black holes (DCBH).

The James Webb Space Telescope, scheduled for launch in 2021, might be able l...