An Echo of Supernova 2008bk

摘要: I have discovered a prominent light echo around the low-luminosity Type II-Plateau Supernova (SN) 2008bk in NGC 7793, seen archival images obtained with Wide Field Channel of Advanced Camera for Surveys on-board Hubble Space Telescope (HST). The is partial ring, brighter to north and east than south west. analysis present suggests that it due SN pulse scattered by sheet, or sheets, dust located ~15 pc from SN. composition assumed be standard Galactic diffuse interstellar grains. visual extinction responsible A_V ~ 0.05 mag, addition foreground toward host galaxy. That experienced much less overall implies through dense portion medium its environment. late-time HST photometry also clearly demonstrates progenitor star has vanished.