Hubble has bagged the most distant Type Ia supernova ever to have its distance confirmed: dubbed SN Primo, the light we see left it a staggering 9 billion years ago!
It was found as part of an ambitious project using Hubble to look for such distant explosions in the near infrared, and is the first one found in the three-year survey. The project is being led by my old pal (yes, I'm bragging) and Nobel Prize winner Adam Riess, who has long been working with supernova to understand the expansion of the Universe. These types of exploding stars tend to explode in a manner that makes their distance relatively simple to calculate (well, once you've solved a host of problems first, which Adam did, which is why he won the Prize). And since they can be seen at vast distances, this makes them very useful for determining the overall shape and evolution of the Universe.
The top pictures shows the Hubble Ultra Deep Field; nearly everything you see in it is a far-flung galaxy. The boxed region is expanded on the bottom; on the left is one image of it and on the right another taken at a later time. The supernova wasn't there in the first image, but can be seen in the second. Adam's team will continue to use Hubble to look at this region over and again, looking for the tell-tale bright spot that marks the location of a new supernova.
By doing this they will improve our measurements of how the Universe is expanding, including the bizarre acceleration of the expansion discovered - in part by Adam - in 1998. I'll be very interested to see what else they find over the next few years of this project.
Credit: NASA, ESA, A. Riess (Space Telescope Science Institute and The Johns Hopkins University), and S. Rodney (The Johns Hopkins University)