sn 1999ec造句

• "' SN 1999EC "'is a type Ib supernova that was discovered in the interacting galaxy NGC 2207 in October 1999 . It was found on images taken with the Katzman Automatic Imaging Telescope at the Lick Observatory.
• Supernovae have been observed in NGC 2207 in 1975 ( type Ia SN 1975a ), 1999 ( the type Ib SN 1999ec ), 2003 ( type 1b supernova SN 2003H ), and 2013 ( type II supernova SN 2013ai ).