Black hole at center of Milky Way may be blasting out a jet

The supermassive black holes at the centers of many galaxies generate powerful jets, blasting particles thousands of light-years into space. This new image of the Milky Way’s black hole, known as Sagittarius A* (Sgr A*), suggests it may have one, too, but perhaps of a more modest nature.

The image—taken with polarized light—was released today by the Event Horizon Telescope (EHT), a worldwide array of radio telescopes that in 2019 produced the first ever image of a black hole. The new image shows light that is oriented in a particular direction, revealing magnetic field lines around the black hole. Although jets would not be visible in such a zoomed-in image, strong magnetic fields are thought to be essential in launching them.

Although no jet has previously been seen coming from Sgr A*, the new image bears a striking resemblance to an earlier polarized image from the EHT of the black hole at the center of the M87 galaxy, 53 million light-years away. That object is about 1600 times the mass of Sgr A* and fires a jet that extends 5000 light-years out into space, but the similarity suggests the Milky Way could have a jet, too. Researchers now hope future enhancements of the EHT will help them find it and if they do it could give astronomers a unique close-up view of how supermassive black holes whip up particles into such high-energy magnetic fountains, something that remains poorly understood.