Powerful bursts are occurring in the center of the Milky Way. They are linked to processes surrounding a supermassive black hole. Scientists hope that observing them will help us understand the global patterns of how our star system changes over time.
Observing the center of our galaxy, full of mysteries
Deep in the frozen heart of Antarctica, the South Pole Telescope observes one of the most extreme regions of our galaxy and has just recorded an extraordinary event. Astronomers have discovered powerful stellar flares erupting from stars near the supermassive black hole at the center of the Milky Way. These are not ordinary stellar flares, but releases of energy so intense that even the most dramatic flares of our Sun appear like flickering candles in comparison.
The center of the galaxy is a wild place. Twenty-six thousand light-years away, in the constellation Sagittarius, a black hole with a mass four million times that of the Sun wreaks havoc in space with its gravity, while stars race around it at breakneck speeds. Conditions there are cramped and turbulent, and it is still extremely difficult to conduct research in certain ranges of light.
This is where the South Pole Telescope comes in handy. Operating at millimeter wavelengths, which lie between infrared and radio waves in the electromagnetic spectrum, it can penetrate the dust that obscures our view of the galaxy’s core. The dry air of Antarctica and stable atmosphere make the South Pole an ideal location for this type of observation.
Amazing stellar flares
A research team led by scientists from the University of Illinois at Urbana-Champaign and the National Center for Supercomputing Applications observed the center of the galaxy over several seasons. They looked for temporary phenomena, such as flares that appear and disappear relatively quickly.
Scientists have discovered stellar flares — sudden, sharp bursts of brightness caused by magnetic reconnection in stellar atmospheres. When tangled magnetic field lines break and reconnect, they release enormous amounts of energy through radiation. On our Sun, such flares can disrupt the operation of satellites and power grids on Earth, but near the center of the galaxy, flares are much more energetic.
This discovery is important for several reasons. First, it demonstrates that observations in the millimeter wavelength range can capture these short-lived events, opening up new opportunities for studying stellar activity in dust-obscured regions. Secondly, it provides insight into the population of stars surviving in one of the most extreme environments in our galaxy.
Significance of flares for astronomy
Stars near supermassive black holes face intense tidal forces, harsh radiation conditions, and frequent close encounters with other stars. Understanding which stars can survive there and how they behave helps astronomers form an idea of the evolution of galactic centers and the exotic physics at work in these regions. Flares also serve as probes of the magnetic fields and atmospheric conditions of stars that we can barely observe by other means. Each flare is like a brief flash of a beacon, illuminating properties of stars that would otherwise remain hidden behind galactic dust.
Future observations using the South Pole Telescope and other facilities may reveal whether these flares follow certain patterns, how common they are among different types of stars, and what they tell us about magnetic activity in extreme gravitational environments. As we develop better tools for monitoring temporal events at different wavelengths, the center of our galaxy becomes less mysterious.
According to phys.org
