Photo of the Week for October 20, 2017
The Pinwheel Galaxy, also known as M33, is nicely positioned on autumn evenings for viewing. At magnitude 5.7, M33 is reasonably bright, but its spread-out light can be difficult to detect in a light-polluted sky. However, in ideal conditions far from town, the galaxy can be glimpsed with the naked eye. This wonderfully detailed photo by Marc Ricard shows the galactic Pinwheel in its full glory—complete with delicate spiral arms dotted with red clouds of glowing hydrogen gas. The largest and brightest of these nebulas is catalogued as NGC604 and is visible in modest telescopes.

Marc recorded this M33 image over three nights from Oak Heights, Ontario. He used a QSI 683wsg CCD camera with a set of Astrodon LRGB and H-alpha filters, and a Takahashi FSQ-106ED f/5 apochromatic refractor telescope.