by Dean Salman
Messier 4 which is a famous globular cluster is a common image, but unknown to many is a fantastic example of reflection and emission nebule mixed together. Sh 2-9 is not a large nebula as seen next to M4, but has a nice reflection in the middle. This image was taken with the E-180 F/2.8 astro graph and the ST-10 XME CCD. Hydrogen Alpha filter was used to help bring out the nebula but a RGB composite was needed to preserve the reflection nebula. The total exposure was 5 hours and 10 minutes.