An Etymological Dictionary of Astronomy and Astrophysics

A strong radio source at the center of our Galaxy. It is a complex object with three components: Sgr A West is a thermal radio source made of several dust and gas clouds, which orbit → Sgr A* and fall onto it at velocities as high as 1000 km per second.

Sgr A East is a → non-thermal source, about 25 → light-years across, that appears to be a → supernova remnant.

Sgr A* is the most plausible candidate for the location of a Galactic → supermassive black hole with a mass of about 4 million → solar masses.

See also: → Sagittarius.