Click here for more information. Jan Wisniewski Pinwheel Galaxy was discovered by Messier on Aug. 25, 1764.
Spiral arms are more challenging because of their low contrast.
Measuring about 40,000 ly across, this member of Local Group is 2.4 million ly away and contains only approx. 20 billion stars. Mosaic was assembled with PhotoPaint 8. Wide field mosaic below shows faint outer areas of M33. Images were processed with Mulyti245 and AIP245, then Corel PhotoPaint 8 was used to put the mosaic together.