HKU Astrophysics Research Captures 130 Years of Evolution of a Dying Star

IC418, the “Spirograph Nebula”, creative commons image from Hubble Space Telescope

(Courtesy: NASA (adapted from original Hubble Space Telescope image))

For the first time, the famous “spirograph” Planetary Nebula IC418’s non-explosive stellar evolution has been captured over an unprecedented period of 130 years—almost double the length of a typical human lifetime. These results have recently published in the prestigious Astrophysical Journal Letters by Professor Albert ZIJLSTRA, Professor of Astrophysics at The University of Manchester, and Professor Quentin PARKER, Director of the Laboratory for Space Research at The University of Hong Kong.

Not only is this a new time record for stellar evolution measured in a Planetary Nebula (PN), or indeed perhaps for any star, and by a significant margin, but the findings carry profound implications for stellar evolution itself. Existing models may need to be revised to account for a slower stellar evolutionary process, and the masses at which carbon stars* can form may also need to be adjusted downward (the PN has evolved from a fairly massive carbon star, challenging current theoretical predictions).

The full article can be viewed on HKU website since 20 Aug 2025:

https://www.hku.hk/press/press-releases/detail/28550.html