Pear Tree Observatory

I am still developing the procedures necessary to process one shot color (OSC) camera images. This is the first D90 image I have processed using the color information. The steps to process an OSC camera are totally different than the steps I use to produce color images taken by my science camera. The larger FOV also adds additional complexity. This image is 2.83° wide versus my science camera having an FOV of only 24′ (arc minutes). However, the increased area makes it much easier to image multiple objects without having to assemble a mosaic of smaller images.

This picture is centered on an object in the southern constellation Sagittarius: The Lagoon Nebula. Also known as M 8, it is a large emission nebula being energized by the open star cluster NGC 6530 that lies in it. Also easily visible towards the lower right is M 20 (The Trifid Nebula) containing both emission and reflection nebulae. The small concentration of stars at the upper left is the globular cluster NGC 6544.

Lagoon Nebula (M8) [F:10x120s]

Chart generated by Cartes du Ciel (CdC)

Chart courtesy of IAU/Sky&Telescope

The vertical yellow line that runs all the way through the CdC chart is the ecliptic. Since most asteroids orbit in the plane of the solar system, the image contains a lot of them. I counted 31 identified on the chart by small green dots, but due to the image scale and the asteroid’s magnitudes I couldn’t find any of them.

Both M 8 and M 20 are just visible with binoculars. Using the constellation chart, observe just above the spout of Sagittarius’ Tea Pot asterism (heavy green lines).