Subscribe now

Space

Was a famous supernova an alien invader from another galaxy?

Kepler's Supernova, seen in 1604, is one of the most famous exploding stars ever seen, and now astronomers think it may have been an interloper from another galaxy

By Alex Wilkins

9 May 2025

A composite image of the remnant of Kepler’s Supernova

NASA/CXC/SAO/D.Patnaude

One of the most famous exploding stars ever recorded by humanity may have been an invader from another galaxy, according to a new analysis of its movements. What is more, alien stars like this might be behind 1 per cent of all the supernovae we see in the galaxy.

In 1604, astronomers saw a new, incredibly bright star appear in the sky, outshining any other. German astronomer Johannes Kepler, who also derived some of the first laws of planetary motion, observed the star for a year to track its…

Sign up to our weekly newsletter

Receive a weekly dose of discovery in your inbox! We'll also keep you up to date with New Scientist events and special offers.

Sign up

To continue reading, subscribe today with our introductory offers

Piano Exit Overlay Banner Mobile Piano Exit Overlay Banner Desktop