Ring Nebula
M57 / NGC 6720
Dora’s favorite planetary nebula imaged on the night of the summer solstice. In the middle is a (now) white dwarf. It is actually 200x as bright as the Sun, but is 2,400 light-years away. This nebula is tiny (when viewed from Earth), just 1.5 by 1 arcminutes. It only started the expansion 200-600 years ago!
In the lower right corner, marked Sheliak, is a 6 component star system, locked in an elaborate dance of gravity.
Technical details
| Telescope | Skywatcher Esprit 100ED (f/5.5) |
| Filter | Astrodon LRGB Gen2 E-Series |
| Field flattener | Skywatcher Esprit (1x) |
| Camera | QHYCCD 268m, -15°C, Mode 1, Gain 56, Offset 30 |
| Resolution | 5950x3900 (cropped only) |
| Light frames | L: 8/8 (120s), 16m total |
| R: 8/8 (120s), 16m total | |
| G: 8/8 (120s), 16m total | |
| B: 8/8 (120s), 16m total | |
| 1h4m total | |
| Flat frames | - (artificial) |
| Darkflat frames | - |
| Dark frames | - |
| Bias frames | 32 (3s) |
| Location | Bolton, UK |
| Local time | 2022-06-21 23:20 - 00:41 |
| Image center | 18h53m35s +33°01'48" |
| Field of view | 2°18’ x 1°31’ (rotation 72°) |