Chandra X-ray Images of NGC 4649
NGC 4649 is a giant elliptical galaxy about 51 million light years from Earth in the constellation Virgo. By applying a new technique, scientists used Chandra data to measure the black hole at the galaxy's center to be about 3.4 billion times more massive than the Sun. The value from this X-ray technique is consistent with a more traditional method observing the motions of stars near the black hole in optical light. NGC 4649 is now one of only a handful of galaxies for which the mass of a supermassive black hole has been measured with two different methods.
Scale: Cropped image (left) is 26 arcsec across.
(Credit: NASA/CXC/Univ. of California Irvine/P.Humphrey et al.)

Hubble Optical Images of NGC 4649
This image from the Hubble Space Telescope shows the giant elliptical galaxy, NGC 4649, located about 51 million light years from Earth. Although NGC 4649 contains one of the biggest black holes in the local Universe, there are no overt signs of its presence because the black hole is in a dormant state. The lack of a bright central point in either the X-ray (#1 above) or optical images shows that the supermassive black hole does not appear to be rapidly pulling in material towards its event horizon, nor generating copious amounts of light as it grows.
Scale: Cropped image (left) is 26 arcsec across.
(Credit: NASA/STScI)