Spiral in Canes Venatici with an active nucleus and extra 'anomalous' arms in H-alpha. ~24 million ly.
Scope: ~2500mm: 127-150mm Mak/SCT (+Barlow)
Camera: Colour OSC (e.g. IMX533/585) + UV/IR cut
Exposure: 120-180s subs, 3h+ total (guided)
