Another other double-double
Posted 14 July 2013 - 01:53 AM
Posted 14 July 2013 - 02:37 AM
Not too far north lies xi Sco, which is an easy double-double in smaller scopes. And the Struve 2470/2474 pairs in Lyra make an even easier--and almost spookily symmetrical--double-double for small scopes.
Posted 14 July 2013 - 08:05 AM
You are right,Nu Sco is a beautiful double-double star.
I was successful at splitting this more times with my 125mm F/7 Newtonian.
I just would like to add Nu Sco as being a binocular double star.During the Summer , Nu Sco is one of my regular target for binocular observing.Most recently I saw Nu Sco as double last week through my Baigish 10x50mm binocular.
Thank you for clarifying an unanswered question I made on another forum.
About one week ago I incidentally stumbled upon Xi Sco while observing with my 60x700mm refractor.It was unknown to me until than.
Both pairs were split at 42x,using a 16.7 mm IOR Huygenian.
Another double-double to be added to the list is Gamma Delphini and Struve 2725 visible in the same field.
For my 60x700mm refractor ,Struve 2725 is quite close to the limit for this instrument.I split this recently at 93x/Clestron 7.5mm ''orange'' Plossl,but only because I knew before hand it is a double star.
It was not obvious at all.
Posted 14 July 2013 - 08:09 AM
What aperture/FOV may be needed to catch a view of IC 4592?
Posted 14 July 2013 - 10:02 AM
Lost the symmetrical appearance they used to have? I wasn't aware of either variability or sufficient differential proper motion to result in any change of note over a human lifetime.
IC 4592 has very low surface brightness. Due this, and the large size of about 1.5 degrees, a large bino is your best instrument. Two eyes provide an increase in signal to noise of 41%, which can make the difference. I've glimpsed it with a 22X100 bino under a fairly dark sky (zenithal surface brightness of 21.4 magnitudes per square arcsecond) at my latitude of 45N. I'd love to see it higher in the sky than the 25 degrees it reaches here, where the contrast would be rather better. I'm not sure if any filter would improve the view, but maybe a broadband LPR filter could deliver a slight gain in contrast.
Posted 14 July 2013 - 01:58 PM
Posted 14 July 2013 - 02:05 PM
Posted 02 August 2013 - 05:09 PM
I recently took a star trail photo of 2470/2474 and it
sure looks symmetrical to me.
Posted 02 August 2013 - 07:50 PM
Posted 04 August 2013 - 10:24 PM
Posted 04 August 2013 - 11:03 PM
Posted 05 August 2013 - 01:11 AM
I am more than happy to go back and do it a little closer, I wanted to make sure I was looking at the right thing.
Posted 05 August 2013 - 07:23 AM
Posted 05 August 2013 - 07:26 AM
Posted 05 August 2013 - 09:34 AM
Posted 05 August 2013 - 09:41 AM
P.S. Can you estimate the magnification used in that photo?
Posted 05 August 2013 - 10:24 AM
Posted 05 August 2013 - 11:21 AM
Posted 05 August 2013 - 02:03 PM
Posted 07 August 2013 - 08:35 AM
Posted 07 August 2013 - 05:06 PM