Xi Scorpii - the “other” double double.

[IB20]

Had no idea this target was so easy to get. When you think of Scorpius, you automatically think of viewing things through the most convoluted of house gaps or viewing through a window.

Well it’s a cracking target, at 114x I’m sat there thinking this target splits easily, that’s that. Little did I know that the primary is actually another double with a separation of 1.1”! I only had the Tak out, with a theoretical split of 1.5” so I wasn’t too hopeful at getting much. Really banging the mag up with the 3.5mm XW (superb eyepiece btw) I could definitely determine elongation with the occasional notch however, this was confirmed with the 4mm TOE (just so clean). Even different colouration was observed, yellow and blue-white, which was most pleasing. 

It’s almost certainly gettable with the dob so I’ll have a go next opportunity I get to split it. 

 

[markse68]

Didn't know about this one IB20- will check it out tonight with the Tal 200K while trying for Antares

Mark

[Zermelo]

Thanks for reminding me about this one, I've added it to tonight's list.

I did the easier split AB from C last year, but not AB. It ought to be possible with the 127 with decent seeing.
There's also the nearby pair Σ1999, which is apparently part of the same system.

[IB20]

Ha yeah forgot to mention I went for Antares. No dice! The heat made it even more difficult than usual, there is the occasional fleeting companion though. I tried the UHC filter but all I got was reflection. 

[IB20]

18 minutes ago, Zermelo said:

Thanks for reminding me about this one, I've added it to tonight's list.

I did the easier split AB from C last year, but not AB. It ought to be possible with the 127 with decent seeing.
There's also the nearby pair Σ1999, which is apparently part of the same system.

Should be doable but it’s close! The wind and heat may make it 5x harder than it should be, but good luck! Personally I enjoyed fitting all 4.5 stars in even in a Tak TOE Ortho, I’m sure they aren’t 52°!

[markse68]

Could barely find Antares last night the transparent was so bad- the moon was really dim! But next time we get a clearer night this is on my list 👍

[Nik271]

I have been trying Xi Sco a number ot times recently and only last night managed to split the close pair AB. I used my 127 SW Mak and had to up the magnification to x250. The seeing was quite good and I could intermittently split the two AB components, oriented aproximately North-South. The CD pair was much easier and further away. It is suprising that the two pairs are gravitationally bound, which is what their common proper motion indicates. Perhaps the imminent DR3 release of Gaia will give more precise information for this system.

The magnification was also a good test of my new surveyor tripod which I adapted to the AZ5 mount head. For £70 these things are amazingly stable and portable. 

By the way, there a number of splendid targets in the same area e.g.  Nu Sco a fine quadtruple star, and Lambda Oph, a triple star. Good seeing is required to get the close pairs in them, but in principle a 4 inch refractor could show them all. With my 127 Mak (which has just 120mm aperture) these gave excellent views in good seeing.  

 

[MylesGibson]

On 18/06/2022 at 16:51, Nik271 said:

I have been trying Xi Sco a number ot times recently and only last night managed to split the close pair AB. I used my 127 SW Mak and had to up the magnification to x250. The seeing was quite good and I could intermittently split the two AB components, oriented aproximately North-South. The CD pair was much easier and further away. It is suprising that the two pairs are gravitationally bound, which is what their common proper motion indicates. Perhaps the imminent DR3 release of Gaia will give more precise information for this system.

The magnification was also a good test of my new surveyor tripod which I adapted to the AZ5 mount head. For £70 these things are amazingly stable and portable. 

By the way, there a number of splendid targets in the same area e.g.  Nu Sco a fine quadtruple star, and Lambda Oph, a triple star. Good seeing is required to get the close pairs in them, but in principle a 4 inch refractor could show them all. With my 127 Mak (which has just 120mm aperture) these gave excellent views in good seeing.  

 

Those are some good targets. It has been a while since I have gone double star hunting. Need to get a new list together!

[chiltonstar]

I managed a look tonight - I had to use my "grab 'n goto" (127 Mak, AZ GTi) to find Xi Sco as the sky was so bright.

Primary just elongated and occasionally split at x220; the fainter orange companion was clearly visible some distance from the primary pair. The other pair were easily split, but less interesting - I couldn't see any colour difference.

An interesting double-double - many thanks to IB20 (and AN June edition).

Chris

[Mr Spock]

It's a bit low here but I'll give it a go. Most likely with the 12" though as 1.1" is right on the limit of my 102mm.

[Cosmic Geoff]

I observed this last night with my C8 and a magnification of about x250 as an easy double-double (7.9" and 11.9")  Splitting the 1.1" AB would have been a tough call under these conditions.

I could also just see the split of Nu Scorpii CD in the multiple Nu Scorpii system - another visual double-double (actually septuple)

[markse68]

Thanks IB20 that was an enjoyable double to find and split. And pleasing to find out my new Tal 200K is a decent splitter! The transparency and seeing are good here tonight and I could just split the AB with a 10mm which I think is 200x. I didn't detect much colour difference between them though. I then moved on to check out Pi Aquilae which the Tal split nicely too. No joy with Antares though. It's been too long since I had a go at splitting tight doubles and it always surprises me how much enjoyment it brings  

Mark

Edited June 22, 2022 by markse68