The giant radio galaxy DA 240: still some surprises

The nature of the Giant Radio Galaxies DA 240 and 3C 236 was
first revealed in Westerbork 49 cm maps made by Tony Willis,
Andrew Wilson and myself in 1974. Here I will consider some of the
steps leading up to the discovery, and review the findings of
subsequent studies of DA 240. The hot spots in both lobes are not
at the leading edges, but rather surrounded by diffuse emission.
Although the hot spots are very asymmetrical in luminosity, their
morphologies are strikingly similar. DA 240 is the brightest member
of a small group of galaxies, which is unusually aligned with the
radio emission; other, possibly related examples of alignment will
be discussed.