Hot and cold: an ice giant orbiting a white dwarf

In a few billion years, when our Sun has exhausted its supply of fuel, it will first turn into a red giant and then collapse to form a white dwarf. Some planets of our Solar System will probably survive this time (if they’re not flung out into deep space). Astronomers know this will happen – theoretically. But until now, nobody had ever found a white dwarf with a planet in orbit around it.

So, it’s understandable why researchers are so excited about the discovery of WDJ0914+1914, which is...