David Malin's deep image of M89, obtained with the UK Schmidt Telescope, shows many interesting features which are not detectable in conventional images (cf. the inset, which is a conventional image at same scale) of this Virgo Cluster galaxy: First, this galaxy is obviously much larger, as its faint outer regions reach much more far out than can be seen on the usual photographs; therefore, it seems likely that a significant portion of its mass is in this low luminosity outskirts of the galaxy. Second, an extremely faint envelope can be detected which surrounds the galaxy at about 150,000 light years distance, and is best visible in the upper right and below the galaxy. This photo is the discovery image of this faint structure, and was originally published by David Malin (Malin 1979). Third, a jetlike structure is obvious in the right part of our image, which may be a galaxy which is currently disrupted by tidal forces, in a close encounter with giant M89.
While the positive image on the right resembles more the visual impression, the negetive reproduction (left) lets see the fainter details more clearly.
Above images are copyrighted by the Australian Astronomical Observatory; see their usage policy.
For technical info on deep astrophotography, look at David Malin's webpage on special photographic techniques.
The discovery of M89's ring stimulated work to compile A catalog of elliptical galaxies with shells (Malin and Dave Carter 1983).
References
Last Modification: May 23, 2000