Helen Usher Profile Topics Started Replies Created Engagements Favourites Search topics: Topics Engaged In Viewing 2 topics - 1 through 2 (of 2 total) Topic Voices Posts Last Post new visual comet discovery by Don Machholz 1 2 Started by: Denis Buczynski in: Comets 10 26 5 years, 5 months ago David Swan Imaging comets with a OSC CCD? Started by: Helen Usher in: Comets 3 3 5 years, 5 months ago Nick James Viewing 2 topics - 1 through 2 (of 2 total)