New Hubble Timelapse – Not science fiction, real science! This happened 70 million years ago as dinosaurs were roaming our Earth. We’re only seeing it now because that’s how long it takes for the light from the event to travel here. One wonders, were there planets circling that star?
Astronomers have been waiting centuries to see a supernova in our own galaxy, but watch thousands a year elsewhere in the universe. Most, however, are billions of light-years away, so in 2018 when an explosion was seen a mere 70 million light-years away the Hubble telescope paid attention. Now NASA has released a timelapse of nearly a year of observations so we can watch it in all its glory.
OK, 70 million light-years is an unimaginable distance by human standards; so vast that when the explosion occurred dinosaurs were still dominating the Earth. Yet in the vastness of the cosmos, it’s really quite close. The galaxy NGC 2525, where the event occurred, was among the first to be discovered way back in 1791 when William Herschel was making some of the first records of what we now know to be cities of stars beyond our own galaxy. It’s closeness and beautiful structure makes it a favorite for amateur astronomers.
The event, known as SN2018gv, gained an extra allocation of Hubble’s precious time because it was a Type Ia supernova, the product of a white dwarf drawing so much material off a neighboring star it passed the critical mass threshold to blow up. Type Ias are consistent in their intrinsic peak brightness, an astonishing 5 billion times that of the Sun. Consequently, by measuring their light, we can calculate the distance to their host galaxy.