5 x 240 sec exposures, ISO 800, processed with 30 bias and 30 dark frames using DSS, XnView, StarTools, and NeatImage

Extragalactic Stars in NGC 206 (within M31), Andromeda

I was inspired by Jef De Wit's beautiful sketch of these extragalactic stars made by visual observation with a 30cm Dobsonian. I searched for these stars on my photographic images of the Andromeda galaxy taken with a small TSAPO100Q astrograph. To my surprise, I found them to be quite prominent on a highly cropped image. It is difficult to believe they are 2.5 million LY distant, and not merely foreground stars.

Please see Jef's post here:
https://www.cloudynights.com/topic/634316-sketching-extra-galactic-stars-in-ngc-206/

On the left is the original image from which the crop was taken. The image was made with a TSAPO100Q astrograph, Celestron AVX mount, Canon T3i camera, and Orion SSAGpro 60mm F/4 autoguider. It is a stack of 5 x 240 sec exposures, ISO 800, processed with 30 bias and 30 dark frames using DSS, XnView, StarTools, and NeatImage.

NGC 206 is a large OB Association, a type of open cluster, composed of more than 300 very hot, young stars of spectral classes O and B, together with thousands of intermediate and smaller stars. The seven stars visible on the cropped image, ranging in apparent magnitude between 14.8 and 16.0, are the very largest and brightest. They are thought to be less than 10 million years old, while the older parts of the cluster originated about 50 million years ago. The cluster, located in the SW spiral arms of the Andromeda galaxy, is 4,000 LY in diameter. It evolved from a giant molecular cloud comparable in size to the massive Tarantula Nebula in the Large Magellanic Cloud, which is one of the largest in the Local Group of galaxies.