The icy blue wings of a bipolar planetary nebula
Planetary nebulae such as Hen 2-437 form when an ageing low-mass star — such as the Sun — reaches the final stages of life. The star swells to become a red giant, before casting off its gaseous outer layers into space. Hen 2-437 is a bipolar nebula — the material ejected by the dying star has streamed out into space to create the two icy blue lobes pictured here.