M51 observing by DOLoRes

The grand design spiral M51 and its companion NGC 5195 at a distance of 20 million ligth years from the Galileo telescope and its imaging-spectropgraph camera d.o.lo.res. The composite image was obtained in the B, V, and R passbands in a night with a seeing of 1.0 arcsec. Clearly visible are the nebulae in the spiral arm (bluer) and the older stars in the bulge (red) of M51. NGC 5195 is orbiting the bigger galaxy with a period of 500 million years and passed nearby 70 million years ago, causing the spectacular spiral pattern.