Pinwheel Galaxy M101 in Ursa Major
Galaxy M101 is large but faint, with only a vague smudge visible though small telescopes from the suburbs.  Only with larger telescopes from a dark rural
site can one detect the hint of spiral structure.  At a distance of 27 million light years, M101's huge size of 170,000 light years is 70% larger than our own
Milky Way Galaxy, making it one of the largest known disk galaxies.   With long exposure astrophotographs such as this, striking asymmetry of the extended
spiral arms is revealed.

The image above combined 135 minutes of unbinned clear luminance with 95 minutes of red, and 90 minutes each of green blue exposures binned 2 x 2.  A
QSI-583wsg camera was used through an Astro-physics 300 mm f3.8 Riccardi-Honders Astrograph on an AP 1200 GTO mount.

The image immediately below, obtained 5 years earlier, combined 115 minutes of clear luminance with 70 minutes of H-alpha, combined with
Red-Green-Blue exposures of 20, 15, and 15 minutes respectively.  I used an ST10-XME camera with Astrodon filters through a TEC140 at my
observatory.

This image at the bottom of the page, obtained 7 years earlier from my light-polluted backyard observing deck, combined 4 hours of Luminence exposures
with Red-Green-Blue exposures of 30, 30, and 45 minutes respectively.  An ST10XME camera was used through a Celestron C8 telescope with a 0.67x
reducer.
Music:  Maybe I'm Amazed, Paul McCartney
click on image for larger size