My First One-Second Split Of A Double Star

[cloudsweeper]

5.00pm, 10" Dob.  Target - O Sigma 418 in Cygnus, an 8th mag matched pair, with (according to CDSA) a 1" separation.

I got Aljanah in the eyepiece using x35 / 2.04deg, then made a hop of just over 2deg to target.  I raised the mag to x318, calculating that that should do the trick, then spent some many minutes making sure I was still on target.  It was very tricky since the 'scope was wobbling a great deal at that mag, and of course tracking was also a bit of a problem.  

Patience won out however, and I briefly, yet clearly saw the split - the two matched stars "side by side", very close, but clearly separate.  This is the tightest spacing I have so far managed to resolve.

So now I shall make further attempts at similar doubles, high in the sky, and fairly matched, and even at slightly closer separations.  

A very challenging and also rewarding hour!

Doug.

Edited November 26, 2020 by cloudsweeper

[John]

Well done Doug

 

[JeremyS]

Nice job Doug @cloudsweeper 👍

[Mark at Beaufort]

Doug that is really good. Anyway can you help because I cannot find a reference to Sigma 418 in Cygnus. I have looked in Sissy Haas's double star book and my Cambridge double star atlas but cannot identify the double. Have you the RA and Dec?

[Mr Spock]

ΟΣ (STT) 418? 8.23 + 8.27 sep 0.9" - RA 20 54 50  Dec +32 42 23

[Stu]

22 minutes ago, Mark at Beaufort said:

Doug that is really good. Anyway can you help because I cannot find a reference to Sigma 418 in Cygnus. I have looked in Sissy Haas's double star book and my Cambridge double star atlas but cannot identify the double. Have you the RA and Dec?

I guess it must be Struve 418? Separation is 0.9” according to SkySafari?

Nice one Doug. I used to think there was no way to split these really tight ones but it gets easier with practice.

[cloudsweeper]

23 minutes ago, Mark at Beaufort said:

Doug that is really good. Anyway can you help because I cannot find a reference to Sigma 418 in Cygnus. I have looked in Sissy Haas's double star book and my Cambridge double star atlas but cannot identify the double. Have you the RA and Dec?

Sure thing Mark - it's OSig418, not Sig418.  I can't see it in Sissy Haas.  Its SAO is 70660.  It's a good one to get into really tight doubles because the stars are well matched.

What I really want now is a 10" frac on a stable mount!!!  😉

Doug.

[Xilman]

1 hour ago, cloudsweeper said:

5.00pm, 10" Dob.  Target - O Sigma 418 in Cygnus, an 8th mag matched pair, with (according to CDSA) a 1" separation.

I got Aljanah in the eyepiece using x35 / 2.04deg, then made a hop of just over 2deg to target.  I raised the mag to x318, calculating that that should do the trick, then spent some many minutes making sure I was still on target.  It was very tricky since the 'scope was wobbling a great deal at that mag, and of course tracking was also a bit of a problem.  

Patience won out however, and I briefly, yet clearly saw the split - the two matched stars "side by side", very close, but clearly separate.  This is the tightest spacing I have so far managed to resolve.

So now I shall make further attempts at similar doubles, high in the sky, and fairly matched, and even at slightly closer separations.  

A very challenging and also rewarding hour!

Doug.

Impressive!

I have a 10" Dob but I doubt very much that I will be able to come close to matching your achievement.

[cloudsweeper]

9 minutes ago, Stu said:

I guess it must be Struve 418? Separation is 0.9” according to SkySafari?

Nice one Doug. I used to think there was no way to split these really tight ones but it gets easier with practice.

Thanks Stu.  Yes, that's the one - 0.9" eh?  I've done better than I thought!  😉

Doug.

[Mark at Beaufort]

2 hours ago, Mr Spock said:

ΟΣ (STT) 418? 8.23 + 8.27 sep 0.9" - RA 20 54 50  Dec +32 42 23

Thanks Michael. Its not marked in the Cambridge Double Star atlas nor the Uranometria atlas although it is in Interstellarum. Doug @cloudsweeper you really found a difficult one - not only to split but also find.

I will have a go with my 12" Dob - thanks Doug 

[Mr Spock]

I'll have a go at that with my 150mm Mak (when my mount arrives). See how it goes. The C925 I used to have did split a 0.7" similar equal double a while back at x394. But conditions were good that night.

36 minutes ago, Mark at Beaufort said:

Thanks Michael. Its not marked in the Cambridge Double Star atlas nor the Uranometria atlas although it is in Interstellarum.

I can see it in Cambridge. It's just above the left bit of the veil next to the 6992 text.

[Mark at Beaufort]

10 hours ago, Mr Spock said:

I'll have a go at that with my 150mm Mak (when my mount arrives). See how it goes. The C925 I used to have did split a 0.7" similar equal double a while back at x394. But conditions were good that night.

I can see it in Cambridge. It's just above the left bit of the veil next to the 6992 text.

Thanks Michael - what I should have stated is there was no text to indicate the double. Anyway I am looking forward to your first light on the iOptron after the mount has arrived. Hopefully, it will be good on doubles for you.

[cloudsweeper]

12 hours ago, Mark at Beaufort said:

Thanks Michael. Its not marked in the Cambridge Double Star atlas nor the Uranometria atlas although it is in Interstellarum. Doug @cloudsweeper you really found a difficult one - not only to split but also find.

I will have a go with my 12" Dob - thanks Doug 

Here it is Mark - CDSA (2nd edition), page 115:

Doug.

[Mark at Beaufort]

Thanks Doug that is really useful - my CDSA is the first edition which does not show it in the detailed text at the back of the book.

[cloudsweeper]

2 minutes ago, Mark at Beaufort said:

Thanks Doug that is really useful - my CDSA is the first edition which does not show in the detailed text at the back of the book.

Thought that might be the case, Mark!  I believe the first ed. also lacks SAO numbers?  I use them via Stellarium to locate targets.

Doug.

[Mark at Beaufort]

1 hour ago, cloudsweeper said:

Thought that might be the case, Mark!  I believe the first ed. also lacks SAO numbers?  I use them via Stellarium to locate targets.

Doug.

Doug I have been looking at your attached photo showing  the SAO numbers which are not included in the first edition. It certainly helps using the SAO number in Stellarium. Perhaps I might consider an upgrade.

[Mr Spock]

Here it is on my chart:

[Mark at Beaufort]

Thanks Michael - it does appear that the 2nd edition is a good improvement.