Berkeley 17 in Auriga

Dear Group,

The oldest (or second oldest) open star cluster in our galaxy is Berkeley 17 in Auriga with an estimated age of 10.06 billion years. Lying at a distance of 8,800 light-years away, the cluster is quite dim with a magnitude of only 14.0.

NGC 6791 in Lyra has produced conflicting age estimates including a figure of 10.20 billion years. As a result, there is some ambiguity as to whether NGC 6791 or Berkeley 17 is the oldest cluster.

Further details and a photo based on two hours total exposure is available at www.perseus.gr/Astro-DSO-Cluster-Berkeley-17.htm . Clicking on the image will yield an image with better image scale for viewing.

Clear skies!

That is a really nice shot Anto, the clarity, natural colours of the stars, and a sense of depth is really there. But the cluster itself is, well, unremarkable! Having never seen Berkely before, and from your description about its age, I would have thought that it would have been more compact. It seems to be mostly the younger clusters that are more diffuse in our galaxy. This one seems to be one of those exceptions. Considering it must be on our own arm of the Milky Way (given its distance), it is among some relatively young neighbours.

Seanie.

Hi Seanie,

Please note that this cluster is only mag 14 and its brightest member star is only mag 16.0. If we use the Perseus Double as an example where the magnitude of the two clusters is around 5.4, Berkeley 17 is 2700x fainter. In other words, this is a VERY dim cluster and which is illustrated by the pinpoint pricks of light from the member stars which characterize the cluster in my photo.

I have searched the internet extensively and could only find one other photo of Berkeley 17. I suspect this is so because of the great dimness of the cluster. Who else is twisted enough to image such a dim cluster. :lol:

16 magnitude!!, I didnt realise that, that makes it an excellent capture.

Who else is twisted enough..>

Found this adsabs.harvard.edu/cgi-bin/nph-bib_query....825C&db_key=AST which has a whole paper dedicated to 17 and 18. May be of interest to those twisted people (half way down click the button to bring you to the high resolution PDF image)

Well then, Anto, you've done a good job in capturing it!