Another globular clusters from the Messier catalogue in constellation Ophiuchus.

This one is about 16400 light years away and belongs to the inner halo of globular star clusters in our galaxy. During its lifetime it has already lost a large fraction of it original mass, because it had to pass through inner denser parts of our Milky Way Galaxy on its billion years of orbiting our galaxy‘s center. This is concluded from measurements indicating that this cluster has unusually few low mass stars. Low mass stars are more sensitive to tidal forces when the cluster comes close to the galaxy center.

This image is my first image with an older CCD camera which I got for free, because it suffered from icing on the sensor. So I got it at least temporarily fixed … it‘s up and running again.

But I know now, why modern CMOS sensors are selling so much better: the handling is much easier and the technical specs are so much better in most respects … I am feeling as if I work with a dinosaur … but in the end, it can still produce very good result … it needs just a bit more effort.

The result is not perfect: backfocus was not great, seeing and guiding was pretty bad that night, and exposure time was to short. Anyway, nights are short these days and until I had the system working there was not much time left.

Celestron EdgeHD8

F=2080mm
Baader broadband color filters RGB
FLI ML8300
R: 20x60sec
G: 20x60sec
B: 20x60sec
Total integration time 1h
Bortle 4-5

PixInsight