What is… a Supernova?
The new star was brighter than any other, outshining even Venus. Records say it was as bright as the Moon during the day, and by night cast shadows as people walked in the street. It was, astrologers and priests agreed, a sign from God. But what did it mean? Did it foretell plague and famine, as priests across the Middle East argued? Or was it a symbol of God’s favour, as the Chinese emperor claimed?
Whatever the meaning, the new star gradually faded away. After dramatically shining through the summer of the year 1006AD, the star was lost altogether several years later. The strange event was not without precedent. Ancient astronomers even had a name for such visitors— guest stars. The ancients knew that the night sky changed, albeit rarely, and watched the skies carefully for heavenly signs.
Thanks to their detailed observations, we now have a record of the night sky going back thousands of years. Modern astronomers have searched through these records, assigning scientific explanations to the strange sightings of the past. Guest stars, like that of 1006AD, are most commonly supernova, the final catastrophic moments of giant stars.
Stars spend most of their lives in a delicate balance. The tremendous weight of the star pulls inwards, trying to crush everything together in a single central point. But this creates an enormous pressure at the core of the…
