Doubles In Corona B, Plus Extras

[cloudsweeper]

10.00pm Weds., still, mild, clear.  I seemed to have trouble navigating my way to these targets the other day, so thought I'd make life a bit easier with the 8SE on GoTo.  And so it was...

10.10 - aligned on Spica and Arcturus - quick, easy procedure.

Sigma 1973 CrB - GoTo spot on, and for the rest of the session.  This binary has a separation of 31".  The fainter companion was easily seen at about 1 o'clock, using x56.  Under 2deg away I then saw:

Zeta CrB - a quintuple system, and visual double, 6.4".  Just split at x56, visible companion at about 11 o'clock, fair match.

[Sigma 2022 CrB - binary, 2.2", secondary much fainter - this sat at the top of a backwards "L" of stars.  Tried repeatedly, waiting for more darkness, and increasing mag in stages to over x200 (to improve contrast), all to no avail.]

Sigma 1932 CrB - matched binary, 1.6".  Target was at the apex of an isosceles triangle of stars.  I inserted the zoom for this one, and at x254 got the split - albeit close - secondary at about 4 o'clock, nicely matched.  

75% success then, very pleasing, although despite to advantages of GoTo, the star images in the Cat are generally not a crisp as in my fracs.

To finish, I decided to take further advantage of GoTo by visiting a few favourites - close galaxies M86 and M84 (in Markarian's Chain) - sobering to view these objects way beyond our Milky Way and contemplate what's within them - then M13 globular cluster, x254, showing many bright stars across and around the fuzz (more FOV with a fixed 8mm than in the zoom) - finally another glob, M3, dense, well resolved at x169.

An hour and 40 minutes of enjoyment!

Doug.

 

[markse68]

Hi Doug, nice report and id like to add these to my list but when I search for Sigma 2022 CrB in SS or online I can’t find any reference to it (nor Sigma 1932 or 1973 CrB ) Do these have other designators?

Mark

Edited May 21, 2020 by markse68

[markse68]

I think I got it- they’re Struve catalog nos 👍

[cloudsweeper]

32 minutes ago, markse68 said:

I think I got it- they’re Struve catalog nos 👍

That's it Mark - I usually find targets from the Cambridge Double Star Atlas (2nd ed.), and refer to them according to catalogue unless they have a name or number or Greek letter title.  As for locating them, I note their SAO numbers to find them on Stellarium, and when using GoTo, enter those numbers into the handset.

Doug.

[John]

Great post Doug - more for my next time out as well !