Evidence in NGC 4261

The following figure shows a composite of ground-based optical and radio telescope images of the giant elliptical galaxy NGC 4261, and a high resolution Hubble Space Telescope image of the core of this galaxy.

NGC 4261 has enormous jets shooting from its core and very strong radio frequency emission. It is thought that the jets are powered by a gargantuan black hole of perhaps a half billion solar masses, and that the ring in the Hubble image is a dusty torus (doughnut) that surrounds the black hole. The black hole itself presumably lies inside the small bright spot at the center. Even a billion solar mass black hole would be too small to see in this image, for as we see in the following table, it would only be the size of the Solar System (which has a radius of about 6 billion kilometers).

Radius for Black Hole of a Given Mass
Object Mass Black Hole Radius
Earth 5.98 x 1027 g 0.9 cm
Sun 1.989 x 1033 g 2.9 km
5 Solar Mass Star 9.945 x 1033 g 15 km
Galactic Core 109 Solar Masses 3 x 109 km