I have recently become aware of a group of galaxies that are very close to us, but that are virtually hidden from view. So hidden are they that most were only discovered in my own lifetime.
This group, the Maffei group, is a community of galaxies that lie directly behind the plane of our galaxy and are thus hidden by all of the intervening gas, dust and stars.
Two of these galaxies are named Maffei I and Maffei II and were named for the astronomer who discovered them, Paolo Maffei, in 1968. He suggested that the dim objects were galaxies.
These two objects had, in fact,, been previously catalogued as emission nebulae. Stewart Sharpless listed them as objects 191 and 197 in his Catalogue of H II Regions published in 1959.
Between 1971 and 1973, two groups lead by Hyron Spinrad confirmed that Maffei I and II were galaxies.
A third major galaxy was discovered in 194, using the Dwingeloo 25m radio telescope in the Netherlands and so was named Dwingeloo 1. A small companion galaxy - Dwingeloo 2 - was discovered shortly afterwards.
One galaxy in this group, IC 342, could have been among the most famous galaxies in the sky had it not been in the plane of the Milky Way. Without all of the dust and stars of our own galaxy, it could be viewed as a naked-eye object.
Dwingeloo 1, above, is barely visible.