Stephan's Quintet

[ollypenrice]

One of our guests and I were imaging NGC7331 and Stephan's Quintet last night in the TEC so it seemed logical to see what we could see of these targets in the 14 inch SCT. NGC7331 is very easy and showed up nicely in the 26 Nagler. What images reveal to be three extended spiral arms, closely grouped on the same side, appeared as a soft, fuzzy elongation. The galaxy didn't hold up to higher power.

And so to the Quintet... (It was discovered 'down the road' from me in Marseille in 1877 by the observatory director Edouard Stephan, using an instrument made by Foucault of pendulum fame.) Halton Arp then rendered it highly controversial by noting that one of its components has a radically different redhift from the others, fuelling his refusal to accept redshift as a reliable distance indicator.

All well and good, but could we see it?  Hmmmm... I'm going to say 'yes' but with the caveat that applies to the way astronomers use the word 'see.' I had the starfield in my head from framing up our image so getting to the right spot wasn't too hard. And, yes, there was a cluster of the dimmest of faint glows, best revealed by nodding the scope slightly from side to side in RA. They were certainly there, but a fraction of a magnitude fainter and they wouldn't have been! Right on the limit. We didn't haul out the Dob for comparison but 20 inches do make it easier. It remains very faint even so.

Olly

[Peter Drew]

I was able to see the brighter members of the Quintet in a 10" Newtonian at Kelling Heath, Norfolk, a few years ago. Will be there again for the meeting next month so might try again. 

[Davesellars]

It certainly needs excellent transparency this group.  I'm not sure if I'll get to see it any better than I observed it the other night with my 12".   I was able to just get a hint of it with my 8 SCT last year, The 12" dob makes a large difference.  While I liked my SCT the lack of contrast at times made it more difficult to pull out really faint DSOs and needing higher power to compensate so perhaps this could have been a large factor not seeing the group well since there if the transparency factor meant not supporting higher power to be used.