Program: GN-2009B-Q-4

We propose narrow-band imaging of the face-on spiral galaxy NGC6946 with HeII and continuum filters newly offered with Gemini-N/GMOS to identify the location of Wolf-Rayet (WR) stars. Amongst 8-10m telescopes, HeII filters have previously only been offered in the southern hemisphere (VLT/FORS), with which we have completed a survey of selected galaxies. Our current target, NGC6946, has hosted 9 supernovae within the last century, the highest count of any known galaxy. Locating WR populations in NGC6946 - and M51 in semester 10A - will complete our northern hemisphere survey of nearby galaxies possessing high star-formation rates. The aim of the combined VLT and Gemini study is to firmly establish the progenitor of a future Type Ib/c core-collapse supernova. H-alpha imaging will allow the position of WR stars to be compared with O star populations.