A Dying Star's Final Masterpiece
M27 is a planetary nebula, the result of a sun-like star reaching the end of its life and shedding its outer layers into space. The central star (a hot white dwarf) illuminates these expanding shells of gas. The bright central structure looks like a dumbbell or an eaten apple core, but deep exposures reveal that the nebula is actually much larger, with outer 'petals' of gas stretching far into the surrounding star field. It provides a preview of what our own Sun might look like in about 5 billion years.
Imaging Challenges
- • Dynamic Range: The core is incredibly bright and can be captured in seconds, while the outer halo requires hours of integration to reveal.
- • Internal Detail: The 'knots' and filaments inside the bright green/blue regions are very fine; over-processing can easily turn them into a smooth mush.
- • Color Balance: M27 is a perfect HOO target. Balancing the vivid teal of the Oxygen-III with the deep reds of the Hydrogen-alpha is the key to a striking image.
The central white dwarf of M27 is one of the largest known of its kind, with a radius about 5% that of our Sun.