The Dumbbell Nebula, or M27, is one of the brightest planetary nebulae in the night sky and probably one of the few that are large enough to work well with my focal length.
Despite the name, planetary nebulae have nothing to do with planets. M27 is the outer shell of gas shed by a dying star. The star itself has already turned into a white dwarf, roughly the size of Earth, with about half the mass of the Sun and a surface temperature of around 100,000 K. Its intense ultraviolet radiation makes the surrounding gas glow.
In the image, the inner turquoise region is mostly oxygen OIII, while the reddish outer structures are dominated by hydrogen H-alpha. The shape is not exactly dumbbell-like: to me, it looks more like an apple core or a translucent cocoon.
| Camera | ZWO ASI2600MC |
| Optics | Askar 103 APO |
| Mount | UMi 17S |
| Gain | 0 |
| Sensor Temperature | –10 °C |
| F-ratio | f/7 |
| Exposure | 42 × 300 s |
| Total Integration | 3.5 h |
| Processing | Siril, GraXpert, Affinity |
Annotated
