NGC 6769-70-71 is a tiny group of three galaxies in the constellation of Pavo (Peacock) seemingly not far from the bright globular cluster NGC 6752. Two of the three galaxies are in interaction: NGC 6769 (top right) and NGC 6770 (top left in the drawing). These two galaxies are about 150 million light years away from us. NGC 6771 (bottom) is a background galaxy. It lies about 20 million light years behind its companions.
The eyepiece view is very spectacular: all galaxies show details. NGC 6769 is the brightest. Three brighter patches are visible in it surrounding the inhomogenious central region. These are the brighter parts of the spiral structure (or rather the ring, see below) and the combined light of star forming regions. NGC 6770 is a little fainter. It has an inhomogeious core region as well which sits inside a small bar. A small brighter spot is visible in the easern (left) end of this bar. Two spiral arm fragments were visible - although these were not an easy sight. Particularly the straight arm was difficult to spot that stretches towards NGC 6769. Contrary to their faintness these two details are the salt and pepper of this drawing.
The lower NGC 6771 is very interesting even in itself. Its central region forms a clear X shape on photos. This was not visible in the eyepiece. There was only a bright straight thread running through the galaxy and the bulge.
You can see a photo of NGC 6769-70-71 to the left courtesy of Krisztián Tóth. It was made using a 20" Corrected Dall-Kirkham asztrograph. I rotated and cropped the original photograph to show a similar area of the sky as my inverted drawing.
The real beauty of the system is revealed in the photo. And you can easily see why the trio is nicknamed the "Devil's Mask".
The signs of the interaction (collision in progress) of the two face-on spirals can be seen in the photo as well: the slightly distorted spiral arms made up of young hot blue stars. The lack of such stars is obvious in the third (edge-on) spiral. Here the older stars dominate (yellow in the photo). This galaxy has an X shaped central part formed by the galaxy's inner dynamics.
It is very interesting to compare the ultraviolet images of the trio with those made in visible wavelengths (see below). The ultraviolet image was made with the GALEX space telescope (Galaxy Evolution Explorer) and the optical image was made with one of the biggest ground-based telescopes the 8.2m VLT (Very Large Telescope) of the ESO (European Southern Observatory). In ultraviolet you can basically see only the young hot and massive stars.
Interacting galaxies in Pavo
A member of the M 81 group
Coma Berenices globular clusters
A pair of globular clusters in the spring sky
Perseus planetary nebula
Little Dumbbell Nebula
Face-on grand design spiral galaxy
A unique grand-design barred spiral galaxy in the Virgo Cluster