Messier 20 (called Trifid Nebula) has been captured by me already on Gavdos. This year I had a telescope with shorter focal length, therefore I managed to capture two objects of Messier’s catalogue on one shot. Specifically it’s mentioned Trifid Nebula and M21 Open Cluster (down left from the nebula). The nebula has been already described in my previous post and it’s located not far from M8 Lagoon nebula. The cluster M21 contains approximately 60 stars and it’s characterized by quite dense core, where the distance between neighboring stars is only one light-year.
The picture was taken under dark skies of Milos Island and it’s an integration of only 54 minutes of exposure time.
Technical details:
| Telescope | Newton 150/600 mm |
| Aperture | 150 mm |
| Focal length | 660 mm |
| Mount | iOptron CEM25P |
| Autoguiding | QHYCCD miniGuideScope 130 mm f/4.3, ZWO 174 MM |
| Camera | ZWO 071 Pro @-10C |
| Corrector | Explore Scientific HR coma corrector |
| Filters | Astronomik L-1 - UV IR Block Filter |
| Exposure | 18x180s, Gain 134, bin 1x1, |
| Date | 2018-09-13 |
[…] summer objects in southern skies. Specifically, I captured M4, M6, M7, M8, M9, M17, M18, M19, M20, M21, M22, M23, M24, M25, M28, M30, M31, M33, M45, M55, M56, M62, M69, M70, M73, M75, M80 and M107. […]
[…] opportunity and recapture these nebulae. My first attempt of M20 was done with focal length 917 mm, second one with 630 mm and now I used gentle focal reducer. Focal length 570 mm allowed me to fit both nebulae […]