NGC 588 (right center), NGC 592 (center) and NGC 595 (upper left), HII regions of M33 in Triangulum.
Prominent OB star associations are A28 at top center, A25 to the left of NGC 588, and A21 seen as
the large clump of blue stars to the lower right. Taken Oct 25, 26, 27 and Oct 28, 2011. Imaged
with CCD Lab’s Q285M camera and a Celestron EdgeHD 9.25 at f10, on a Losmandy G11/Gemini mount.
All subframes were binned 1x1. H-alpha subframes were 15 minutes while the RGB subframes were
12 minutes. The RGB subframes were also used to make synthetic luminosity subframes (sL) which was
then blended with H-alpha to form the L channel. The resulting total exposures were L:R:G:B =
((R+G+B)+Ha):(R+Ha): (G): (B) (min) = (168+255): (168+255): (168):(168). Captured with Nebulosity,
calibrated, sigma combined in Iris with other processing using PixInsight LE and Photoshop CS.
North is up.

A previous M33 image of mine can be found here: http://www.pbase.com/jshuder/image/106297415