Comparison of visible hydrogen emission in the NW filament of SN 1006 in data taken at the CTIO Curtis-Schmidt H-alpha, continuum-subtracted (Winkler, et al.) in 1998 (shown in green), and the Hubble ACS data (Raymond et. al) in 2006 (shown in red). The stellar background is from WFPC2 broadband B, V, and I data from 2008 (Hubble Heritage Team).

Credit: NASA, ESA, and L. Frattare (STScI). Science Credit: Hubble data: NASA, ESA, and the Hubble Heritage Team (STScI/AURA); CTIO data: Winkler/CTIO/NOAO/AURA