It wasn’t a very clear night, and this was a back-up target for the not-so-transparent skies.
I had planned to take a set of images testing the procedure for doing a mosaic. Around 9pm, the sky looked decent with hints of the Milky Way overhead. Unfortunately, that didn’t last. So instead of a mosaic, I picked one field, south of the zenith, in what was more-or-less the darkest region of the sky. Then I spent a fair amount of time playing with APT settings. Along the way, I learned how to use APT to do dithering without a guide camera which made me a very happy imager.
| Object | M15, Globular Cluster |
| Camera | ASI1600MM-Pro, LRGB |
| Lens/Scope | AstroTech RC6 |
| Exposure | 23 x 60 sec Red 13 x 40 sec Blue10 x 20 sec Green 27 x 10 sec Luminance |
| Location | Bay Ridge, Brooklyn, NY |
| Processing | PixInsight: more steps than I care to remember |
I was mostly aiming to get Broccia’s cluster (aka “the Coathanger”) in on the upper right of the frame, and that also ended up putting M27 (Dumbell nebula) at the top near left-center.
In spite of being in a fairly light-polluted sky (Bortle 6/7), it’s better than home in Brooklyn (Bortle 9) and the 45 minutes worth of images showed a lot of stars. Too many, in fact. I played some games to darken the fainter stars so as to bring out the constellation a bit more. Naked eye, only 4 of the stars in Sagitta were visible.
For a full set of labels, see https://www.astrobin.com/d343kn/.
