安魂曲超新星：目前为止已见到3次的超新星
2021年11月02日 SN Requiem: A Supernova Seen Three Times So Far Image Credit: NASA, ESA, Hubble; Data: S. A. Rodney (U. South Carolina) et al.; Image Processing: J. DePasquale (STScI) Explanation: We’ve seen this same supernova three times — when will we see it a fourth? When a distant star explodes in a supernova, we’re lucky if we see it even once. In the case of AT 2016jka (“SN Requiem”), because the exploding star happened to be lined up behind the center of a galaxy cluster (MACS J0138 in this case), a comparison of Hubble Space Telescope images demonstrate that we saw it three times. These three supernova images are highlighted in circles near the bottom of the left frame taken in 2016. On the right…