M51, the Whirlpool Galaxy, is presently "catching" a smaller barred spiral galaxy (that's the huge bright hazy structure visible at the end of one spiral "arm"). Once the Whirlpool and its smaller companion merge, the resulting galaxy will be distorted.
M51, the Whirlpool Galaxy
| Right Ascension | 13 : 29.9 (h:m) |
|---|---|
| Declination | +47 : 12 (deg:m) |
| Distance | 37000 (kly) |
| Visual Brightness | 8.4 (mag) |
| Apparent Dimension | 11x7 (arc min) |
NGC 5195, companion to M51
| Right Ascension | 13 : 30.0 (h:m) |
|---|---|
| Declination | +47 : 16 (deg:m) |
| Distance | 37000 (kly) |
| Visual Brightness | 9.6 (mag) |
| Apparent Dimension | 6.4x4.6 (arc min) |
For the amateur, M51 is easy and a showpiece if the sky is dark, but is quite sensitive for light pollution which easily makes it fade in the background. Under very good conditions, even suggestions of its spiral arms can be glanced with telescopes starting from 4-inch. Low magnification is best for viewing this pair.
Where to look? "Under" the Big Dipper's handle! See below:
Here's a larger overview of the region where M51 is located:
It wouldn't be the same without a Hubble image. So here's a great shot of the inner part of the Whirlpool:
