M33 is the third-largest in our Local Group of galaxies, after M31 in Andromeda and our own Milky way galaxy. It is 2.7 million lightyears distant and around 60,000 lightyears in diameter, so around half the size of our own galaxy.
M33 has two main flocculent spiral arms and extensive red areas of hydrogen emission can be seen, sites of star formation. The largest area is to the lower left and is large and bright enough to have its own NGC 604 designation. It is approximately 1400 lightyears in size.
This LRGBHa image is the result of 3h 20m of data capture, over two evenings in October and November 2021 from Horsham. A ZWO ASI2600MM Pro camera was used, through an 8-inch Ritchey-Chretien Cassegrain telescope.
Date: 02/11/2021
Location: Horsham, West Sussex
Photographer: Graham Wilcock
