Galaxy

Nowadays, the Milky Way is a pretty quiet galaxy – but just a few million years ago its central black hole sent off huge flares of radiation.

Astronomers have spotted an event that was thought to happen over millennia play out in a matter of months, as a usually-quiet galaxy suddenly fired up into an energetic quasar – and not just once, but in six different cases.

Given their name, black holes aren’t the kind of places you’d expect to see much light. But sometimes flashes of light are seen as the black holes snack on gas and dust. Earlier this year though the supermassive black hole at the center of our galaxy flared up in an unprecedented light show, and astronomers don’t really know why.

In NGC 6946, better known as the Fireworks galaxy, an extremely bright flare of X-rays was seen to appear and disappear within a matter of weeks.

It looks like a Jackson Pollock painting, but this colorful mess is a new map of the Milky Way, showing strange star structures.

Though it seems empty, the intergalactic medium (IGM) actually contains more matter than galaxies do. Now, astronomers have used simulations to reveal new details about the structure of this matter, showing that “intergalactic pancakes” spanning millions of light-years collapse into a cosmic fog.

A galaxy seems like a hard thing to miss – let alone 39 of them – but that’s exactly what a team of astronomers has just discovered. So where have these countless stars been hiding? About 11.5 billion light-years away, in a part of the light spectrum that’s invisible to many telescopes.

Our home galaxy is right on the border of a void so vast it’s hard to picture. To get a better idea of its shape and size, a team of astronomers has mapped out the edges of this extragalactic emptiness, and calculated just how much gravitational influence it has on the Milky Way.

Physicists at Stanford and the SLAC National Accelerator Laboratory have narrowed down the search for dark matter. Using observations of galaxies orbiting the Milky Way, the team found that dark matter is likely lighter than previously thought – and interacts even less with normal matter.

Hubble has discovered a structure around a black hole thought to be impossible. A small, “malnourished” black hole has a disk of material circling it – a feature thought unique to supermassive black holes. This disc is also so close to the black hole that it’s distorting and stretching the light.

Fast radio bursts (FRBs) are one of the most intriguing mysteries of modern astronomy, so the more of them we can locate, the closer we get to figuring what causes them. Now astronomers have managed to trace an FRB back to its home galaxy, many billions of light-years away.

Scientists have been unable to figure out what fast radio bursts are or where they’re even coming from. Now, a team of astronomers has finally managed to trace one of the signals back to its home galaxy billions of light-years away, meaning we’re closing in on the culprit.