📄 Showing the "Simple" version — "Advanced" is not ready yet. Add it to favorites to help prioritize it. Ask for the full read

Radio telescopes listen to the sky like sensitive ears: they catch the whispers of distant explosions, the hum of galaxies, the crackle of pulsars. But sometimes they pick up a sound that isn't in the catalogs. In 2003, such a sound emerged in the constellation Aquila — a spot in the sky that had been quiet until it suddenly began to speak.

The source was named VT J1906+0849. It lies nearly in the plane of the Milky Way, amid dense clouds of gas and dust. At first, it brightened: by 2014, its radio brightness had tripled compared to the first measurement. Then it began to fade. The story seemed over. But in late 2025, it flared again, like a campfire fed with fresh kindling.

So what is it? Given its distance (at least 15,000 light-years from us) the source is extremely powerful. To shine this brightly in radio, matter must be continuously falling onto a compact object, either a black hole or a neutron star. But here's the puzzle: the Swift X-ray telescope saw no bright X-ray emission, which usually accompanies such "feeding." And the radio waves vary in ways unlike typical black hole binary systems.

The radio spectrum suggests the emission arises in a dense clump where electrons spiral along magnetic field lines. Yet the clump itself barely expands — over five years of observations, its size remained constant, even as brightness and color changed. This happens when a jet is squeezed on all sides, like a stream of water clenched in a fist.

None of this fits the usual patterns. The closest behavioral relative is the famous microquasar SS 433, which ejects narrow jets at a quarter of the speed of light. But VT J1906+0849 is younger and fainter in X-rays. Perhaps its jet hasn't yet punched through a dense cocoon of gas that slows it down and prevents expansion. The jet crashes against the cocoon's walls like water against rock, generating radio waves — while the same dense material quenches X-ray emission.

This scenario explains the flares, the "frozen" size, and the strange wind. If correct, we are witnessing a rare moment: the birth of a microquasar, when a black hole is just beginning to carve its path through matter that has fallen onto it from a companion star.