Cassiopeia Observatory

IC410, IC405, Rosette Nebula

Posted: 28 December 2013

At 1814 MST, viewed Venus, low in the southwestern sky, 83X. Thin crescent was visible, but seeing was bad. Venus kept "breaking up". No imaging.

By 1826 MST, the breezes were getting stronger with frequent stronger gusts. Slewed to IC410 (diffuse nebula), first imaging target of the night. Added the f/6.3 focal reducer, mounted the D7000 DSLR at prime focus of the 8" LX200-ACF using the off-axis guider, slewed to the star Capella, and then began the short wait for astronomical twilight to end.

After doing a focus test image using a Bahtinov Mask, slewed to IC410, and at 1900 MST, did a framing test exposure, guided using a faint guide star, 2 minutes, ISO 6400. Framing was OK and so I did 14 more guided 2-minute exposures. This is a stack of the 15 exposures using Lynkeos, slightly cropped, with an effective exposure of 30 minutes:

The darkness on the right side is due to vignetting from using the focal reducer as the nebula was offcenter in the field-of-view. I hope to try another exposure on a future session with the nebula more centered.

Slewed to IC405 (diffuse nebula) and after slewing around a bit, found a good guide star. I then took a short break to stretch and have some hot chocolate. The wind was getting stronger. I did a framing test exposure of IC405, guided, 2 minutes, ISO 6400, at 1946 MST. Framing was OK so I did 14 more 2-minute exposures. This is a stack of the 15 2-minute exposures using Lynkeos (effective exposure 30 minutes), full-frame:

Slewed to NGC2237 (Rosette Nebula). I had previously imaged NGC2237 on 3 January 2011, using the D7000 DSLR with 145mm focal length lens piggybacked on the 8" LX200-ACF. This night I wanted to image it at prime focus + focal reducer of the 8" telescope. I located a good guide star and then began waiting for the Rosette Nebula to get higher in the sky. At 2032 MST, viewed the Rosette Nebula using the Celestron 12x70 binoculars. The nebula was faintly visible. I then decided to close the obervatory dome while waiting for the nebula to get higher as strong winds were blowing. Re-opened the dome at 2050 MST; the wind was still gusting at times. Decided to start imaging anyway. I did some unguided 1 minute, ISO 6400, framing test exposures while searching for a guide star. No guide star was found so I did 10 1-minute, unguided, ISO 6400, exposures. The images were stacked using Lynkeos for this effective 10 minute exposure, slightly cropped:

Ended imaging at 2112 MST. Removed the camera and viewed the Rosette Nebula using the 2" 24mm UWA eyepiece + focal reducer. The nebula was faintly visible but it was a nice view.