Seyfert galaxies resemble quasars, with extremely luminous cores thought to harbour supermassive black holes. But unlike quasars, which shine with a brilliance that masks details of the host galaxy, Seyfert galaxies are clearly visible, closer and less luminous than their more energetic cousins. The prototypical example is Messier 77. NGC 1566, pictured here, is another stunning example, the second brightest Seyfert galaxy yet discovered. Located some 40 million light years from Earth in the constellation Dorado, NGC 1566 is the brightest member of the Dorado Group of galaxies and is classified as an intermediate spiral galaxy, one that does not have a well-defined “bar” in its central region. This image was captured in 2014 by the Hubble Space Telescope’s Wide Field Camera 3.
The placid appearance of NGC 4889 can fool the unsuspecting observer. But the elliptical galaxy, pictured here in front of hundreds of background galaxies, and deeply embedded within the Coma galaxy cluster in this new image from the NASA/ESA Hubble Space Telescope, harbours a dark secret. At its heart lurks one of the most massive black holes ever discovered.