Globular cluster in Pegasus is very far from Earth, specifically 33 600 light years and its diameter is approximately 175 light years. It contains more than 100 000 stars.
Most of the globular clusters are quite bright (M15 has magnitude 6.2), therefore there is no long exposure required. On the other hand longer exposures might overexpose the core, therefore I selected exposure time to 2 minutes.
| Telescope: | Newton 254/1000 mm |
| Aperture: | 254 mm |
| Focal length: | 730 mm |
| Mount | Gemini GF53f |
| Autoguiding | ZWO 174MM, TS 60/240 mm |
| Camera: | Moravian instruments G2 8300M @-30C |
| Corrector: | ASA 2" reducer 0.73 |
| Filters: | Baader LRGB |
| Exposure: | 26xL 16xRGB, 120 s, bin 1x1 |
| Date: | 2015-11-10 |