Category Astronomy/Space

AR Scorpii

Astronomers studying the unique binary star system AR Scorpii have discovered the brightness of the system has changed over the past decade. The new evidence lends support to an existing theory of how the unusual star emits energy. AR Scorpii consists of a rapidly spinning, magnetized white dwarf star that mysteriously interacts with its companion star. The system was recently found to more than double in brightness on timescales of minutes and hours, but research recently published in The Astrophysical Journal Letters found variability on a timescale of decades.

Researchers at the University of Notre Dame analyzed data on the unique system from the Kepler Space Telescope’s K2 mission taken in 2014 before the star was known to be unusual...

Galaxies from the SAMI survey, imaged with Japan’s Subaru telescope. Credit: D. Taranu (University of Western Australia), C. Foster (University of Sydney), NAOJ (the National Astronomical Observatory of Japan)

For the first time astronomers have measured how a galaxy’s spin affects its shape. It sounds simple, but measuring a galaxy’s true 3D shape is a tricky problem that astronomers first tried to solve 90 years ago. “This is the first time we’ve been able to reliably measure how a galaxy’s shape depends on any of its other properties – in this case, its rotation speed,” said research team leader Dr Caroline Foster of the University of Sydney, who completed this research while working at the Australian Astronomical Observatory.

Galaxies can be shaped like a pancake, a sea urchin or a foo...

This is a ground-based telescopic view of NGC 6791. Credit: NASA, ESA, DSS, and L. Bedin (STScI)

By conducting an orbital analysis, a team of astronomers led by Luis Martinez-Medina of the National Autonomous University of Mexico has uncovered new details about the origin and evolution of the old, metal-rich open cluster NGC 6791. Located about 13,300 light years from the Earth in the Lyra constellation, NGC 6791 is one of the most studied open clusters. It is ~8 billion years and an iron to hydrogen abundance ratio more than twice that of our sun. This makes it one of the oldest and most metal-rich clusters in the Milky Way galaxy. With a mass of approximately 5,000 solar masses, it is also one of the most massive open clusters known to date.

“In this work, we explore possible locations f...