M33 in HaLRGB


Chris Heapy

Macclesfield, UK

The telescope used was a TeleVue NP127is refractor mounted on a Losmandy G11 equatorial mount, guided with a TV Pronto plus SX Lodestar guidecamera. The CCD camera used was an Atik 490EX operating at 1×1 binning (effectively approx 1.1 arcseconds/pixel). All image data was aquired from a suburban back garden in Macclesfield UK.

This image shows the Triangulum Galaxy M33 as an LRGB composite with added Hydrogen-alpha data (in red) to show areas of active star formation. We infer star formation is actively going on because in order for the HII regions to emit light they need to be stimulated with a powerful local source of UV radiation – such as produced by newly formed stars. In effect these areas delineate new star clusters which can be seen here forming predominantly in the galaxy’s crowded spiral arms. The image data consists of 10 x 15min subframes for each of LRGB, plus 10 x 20min subframes for the H-alpha.