Scientists detect towering balloon-like structure near Milky Way’s center
Deborah Byrd in SPACE | September 11, 2019

It’s a huge bipolar gas structure, hundreds of light-years across, centered on our galaxy’s center and near the galaxy’s central supermassive black hole. Astronomers found it with the new, supersensitive MeerKAT telescope in South Africa.

The complex radio emission from the galactic center, as imaged by the South African MeerKAT radio telescope. The newly-discovered giant radio bubbles are the structures running top to bottom in this image. Image via SARAO/Oxford.
Our Milky Way is considered to be a relatively quiescent galaxy, and yet – at its heart – it’s known to have a 4-million-solar-mass black hole: the source of many fascinating and dynamic processes. Yesterday – September 11, 2019 – astronomers announced the discovery in that region of what they’re calling “one of the largest features ever observed” in the center of the Milky Way. This feature is a pair of enormous radio-emitting bubbles, towering above and below the central region of our galaxy. Scientists described it as hourglass-shaped. The entire structure stretches some 1,400 light-years, or about 5% of the distance between our sun and the galaxy’s center.

This new discovery was announced today in the journal Nature, which also published the initial study of the feature. They said in a statement that it:

… dwarfs all other radio structures in the galactic center [and] is likely the result of a phenomenally energetic burst that erupted near the Milky Way’s supermassive black hole a few million years ago.

In other words, said these scientists, they believe features have formed from a violent eruption, presumably emanating from the vicinity of the galactic center and its supermassive black hole, which – over a short period of time – punched through the interstellar medium in opposite directions. As explained in Nature:

The bubbles are gas structures that can be observed because electrons stirring inside them produce radio waves as they are accelerated by magnetic fields.