M13 - The Hercules Great Cluster.

[Taman]

This spectacular globular cluster contains several hundred thousand yellow and blue stars. It is about 25,000 light years away.

This was taken last Sunday.

I very nearly didn't set up as the forecast was for high cloud. I'm glad I did though, as I had some of the best seeing conditions of the year so far. Guiding was just about flat.

The image has very nearly processed itself! Apart from stretching, removing the green background and balancing the colour in Siril, I have done very little to it. I am amazed how sharp the stars are.

18 x 300s, with darks, flats and dark flats. Total exposure time 1 hour 30 minutes.

Processed with DeepSkyStacker, Siril and Photoshop (re-sizing and adding text only).

Taken at f6.3 with the C11, ASI294MC Pro and Optolong L-Pro filter.

Edited May 22, 2020 by Taman

[Pankaj]

Wow. Simply ''out of this world'' picture. Were you sitting on the Hubble telescope while click it ?😆

[Taman]

6 minutes ago, Pankaj said:

Wow. Simply ''out of this world'' picture. Were you sitting on the Hubble telescope while click it ?😆

Thank you! I'lI need a bigger shed for one of those. 😁

I think the 'scope was performing at its absolute limits. Probably won't see another night like that for a while.

[MarkAR]

Excellent image. Very difficult not to burn out the central cluster and I think you've done well.

[Ags]

I believe the blue stars in the cluster are not younger but instead are recent mergers of ancient stars.

[Taman]

7 hours ago, Ags said:

I believe the blue stars in the cluster are not younger but instead are recent mergers of ancient stars.

Thanks for that. I was interested to find out why some of the stars were blue, so I did some research with Google and possibly over-simplified what I read. Here's a link to one article relating to M13 and referring to "blue stragglers" being  new stars created when old stars collide. So it seems the stars are new rather than young?

https://www.nasa.gov/mission_pages/hubble/science/hst_img_20081204.html

Edited May 22, 2020 by Taman

[Ags]

6 hours ago, Taman said:

So it seems the stars are new rather than young?

I would describe them as "recently annoyed"... 😀