12 August 2026
Deep imaging of ionized gas in the Helix Nebula uncovers many curved shock waves around a dying Sun-like star. These ‘bow shocks’ are produced when ejected shells of stellar material break up and race outwards. Their changing shapes imply that the shell fragments are being stripped, shredded and mixed into interstellar gas over roughly 10,000 years.
This is a summary of: van Dokkum, P. et al. Numerous bow shocks in the outer Helix Nebula. Nature 656, 334–337 (2026).
doi: https://doi.org/10.1038/d41586-026-02159-3‘Expert opinion’ is published under a CC BY 4.0 licence and Figure 1 is published under a CC BY-NC-ND 4.0 licence.
ReferencesKwok, S., Purton, C. R. & FitzGerald, P. M. Astrophys. J. 219, L125–L127 (1978).Article
