M87* is the name of the supermassive black hole at the center of the galaxy Messier 87.
M87* lies about 55 million light-years from Earth in the Virgo Cluster. Astronomers estimate its mass at roughly 6.5 billion times the mass of the Sun. Its enormous mass powers the famous relativistic jet extending thousands of light-years from the galaxy’s nucleus.
The Event Horizon Telescope collaboration released the first image of M87* in April 2019. The image showed a bright, uneven ring surrounding a dark central region, produced by the black hole’s gravity and glowing material near it.
The asterisk in “M87*” distinguishes the compact central object from the entire galaxy. Sagittarius A* is a different supermassive black hole, located at the center of the Milky Way.