Reading view

Scientists find closest star to the Milky Way's central black hole

19 August 2026 at 15:56

Sgr A* is the name we've given to the supermassive black hole that sits at the center of the Milky Way. We've known about its presence since the 1970s but only managed to image it within the past few years. In the intervening time, most of our understanding of the object was obtained by watching a group of stars that orbit the black hole, helping us get a good estimate of its mass and size. In essence, those stars acted as instruments that let us peer into an environment we couldn't study any other way.

In Wednesday's issue of Nature, researchers describe a recently discovered star that is on an extremely eccentric orbit that takes it closer to Sgr A* than anything we've previously identified. It gets so close that it may help us get our first measurements of the spin of the black hole.

Reading the spin

There's an entire population of stars that orbit relatively close to Sgr A*. We can estimate their mass based on their brightness and spectral features. Using their masses and a reconstruction of their orbits using several years of data, we can figure out just how supermassive Sgr A* is (nearly 10³⁷ kilograms).

Read full article

Comments

The world's biggest solar telescope caught vortexes on the Sun's surface

Ars Technica - All content

By: Jacek Krywko

7 August 2026 at 13:20

Wherever two fluids slide past each other at different speeds, the boundary between them buckles, then curls, then rolls up into vortexes. It’s called the Kelvin-Helmholtz instability, and the physics behind it was worked out in the late 1860s. We know this instability explains why wind causes ripples on the surface of water and clouds shear into a row of curves.

For decades scientists argued the same thing must be happening with plasma on the surface of the Sun, and yet nobody had been able to confirm it. Now, a team led by David Kuridze and Friedrich Wöger of the National Solar Observatory reports that Kelvin-Helmholtz instabilities are not just visible on the Sun, but they’re ubiquitous. Their new study proposes that this may change the way we think about how heat, mass, and magnetic energy move through the Sun's atmosphere.

Telescope’s test drive

The reason plasma whirlpools on the Sun stayed hidden for so long is rather trivial: They are very small. Their scale sits below what telescopes with mirrors smaller than 2 meters can resolve. For most of the history of solar physics, that has ruled out every telescope on Earth. This changed when the US National Science Foundation opened the Daniel K. Inouye Solar Telescope, a 4-meter instrument in Hawaii and the largest solar telescope in the world. The telescope entered its operational phase back in November 2021.

Read full article

Comments