Astronomy: The source of a shining light from the past

The binary star system responsible for a classical nova eruption in AD 1437, recorded by astronomers at the time, has been identified in a study published in this week’s Nature.

A classical nova is an eruption of brightness from a white dwarf star, powered by the accumulation of hydrogen gas from its companion star in a binary system leading to a runaway thermonuclear reaction. One of the best-located novae of antiquity, recorded by Korean royal astronomers, erupted on 11 March AD 1437. It lay within the tail of the constellation Scorpius and was seen for 14 days before vanishing, consistent with a fast-declining classical nova.

Michael Shara and colleagues used historical observations to track down the binary system responsible for the nova and found that it now exhibits dwarf nova eruptions ― smaller, less bright eruptions. The authors suggest that binary systems with classical nova and dwarf nova eruptions are in fact the same systems, seen at different times.

In an accompanying News & Views article, Steven Shore writes that: “identification of the cataclysmic variable associated with Nova Scorpii 1437 is a lovely piece of historical scholarship.”