Three Faces of Evolving Supernova (Annotated)

As a result of a phenomenon called gravitational lensing, three different moments in a far-off supernova explosion were captured in a single snapshot by the NASA/ESA Hubble Space Telescope. The light from the supernova, which was located behind the galaxy cluster Abell 370, was multiply lensed by the cluster’s immense gravity. This light took three different paths through the cosmic lens of the massive cluster. The three paths were of three different lengths, so when the light arrived at Hubble (on the same day in December 2010), the supernova appeared at three different stages of evolution.

The left panel shows the portion of Abell 370 where the multiple images of the supernova appeared. Panel A, a composite of Hubble observations from 2011 to 2016, shows the locations of the multiply imaged host galaxy after the supernova faded. Panel B, a Hubble picture from December 2010, shows the three images of the host galaxy and the supernova at different phases in its evolution. Panel C, which subtracts the image in Panel B from that in Panel A, shows three different faces of the evolving supernova. Using a similar image subtraction process for multiple filters of data, Panel D shows the different colours of the cooling supernova at three different stages in its evolution.

[Image Description: Five panels are shown. The larger left panel shows the portion of the galaxy cluster Abell 370 where the multiple images of the supernova appeared, which is shown in four panels labelled A through D on the right. These panels show the locations of the multiply imaged host galaxy after a supernova faded and the different colours of the cooling supernova at three different stages in its evolution.]