Crescent Nebula
NGC 6888 / Caldwell 27 / Sharpless 105
The star you see in the middle of the nebula is called WR136. Somewhere around 300,000 years ago it ran out of fuel and became a red giant. It threw off some material, gas and dust, into space. Since then its solar wind sends shockwaves through that cloud, forming it, heating it up, causing it to glow and emit all sorts of radiation.
Technical details
| Telescope | Skywatcher Esprit 100ED (f/5.5) |
| Filter | Atik Narroband 7nm Ha/SII/OIII |
| Field flattener | Skywatcher Esprit (1x) |
| Camera | QHYCCD 268m, -10°C, Mode 1, Gain 56, Offset 30 |
| Resolution | 6176x4143 (cropped) |
| Light frames | H: 17/21 (300s), 1h25m total |
| S: 15/15 (300s), 1h15m total | |
| O: 15/17 (300s), 1h15m total | |
| 3h55m total | |
| Flat frames | 16 each (3s, per channel brightess) |
| Darkflat frames | 32 |
| Dark frames | - |
| Bias frames | - |
| Location | Kalkalpen Nationalpark, Austria |
| Local time | 2022-10-04 22:12 - 23:38 (7 frames) |
| 2022-10-06 20:21 - 22:03 (11 frames) | |
| 2022-10-07 21:01 - 00:25 (29 frames) | |
| Image center | 20h12m09s +38°21'46" |
| Field of view | 2°23’ x 1°36’ (rotation 106°) |