Cygnus doubles and X Sge query.

[Johnny81]

16/09/2024 - 19:53 - 22:07

Good seeing - although some high cloud with moon beginning to wash out from about 21:15. Luckily the moon is behind my house at the moment. 

All in Cygnus with a focus on some more Struve entries (and others). Cygnus is fun as there are a lot of stars, especially in the Gamma Cyg (Sadir region) and easy to get lost. But nothing the trusty 9x50 RACI can't find (sort of)….

STF 2762: Near Zeta Cyg. This was really nice. Tight A-B split at 3.34'' requiring x150 in the Mak 127mm and a wider A-C component.

STF 2700: Well separated, lovely yellow-orange primary

STF 2633: Very difficult, stuff of nightmares... went back to this a few times in the evening. Couldn't see the 11th mag companion even at over 11'' separation. Moon not helping. Two faint wider 11th mag stars at approx. PA: 220/270^o assured me I was looking at the right star when I compared to Simbad imagery. Apparently a quadruple system. Worthy of further investigation with the moon clears off. 

STF 2639: Lovely easy pair at x100 in a lovely area of stars. 

STF 2578: A nice slightly unequal white pair.

STF 2534: Dim (8th mag) pair, easy split at x100

29 Cyg: Situated in a rich area of the heavens. Wide optical companions

STT 394: Easy pair but companion rather faint at roughly PA: 300^o . I am going to stop saying clock positions as I did in my debut Hercules report because the position is mirrored anyway...

19 Cyg: faint companion with a golden primary

HJ 1470: Widish unrelated 9th mag secondary

STF 2609: Partial split of a 1.8'' secondary! Was amazed I could see this and I thought my eyes were playing tricks on me. Pushed at x150 (going up to x187 with the 8mm in the mak is just blegh). I am usually amazed if I can see anything tighter than the easier of the two Double Double stars in Lyra...

I managed 42 individual double stars over the weekend in Vulpecula, Sagitta and Aquila so I am not going to do a full report here. But one star is baffling me:

Does anyone know much about or has observed the variable/double X Sge? Also listed as BUP 203 (I don't know what BUP is unless it is an extended Burnham catalogue)?.

This star was shown on the listing for doubles in Sagitta using Virtalcolony site although the set parameters were: Constellation =SGE, Separation > 4.0, Magnitude of Primary <10.0, and Magnitude Difference < 5.0

Stelle Doppie and Simbad list companions of 12-13 mag with separations wider than 13'' but on Stellarium the star is visually shown as having an 8.3 mag close companion??

Nevertheless,  very red colour but really tiny even at x150 through a 127mm Mak and any companions too dim to see.

[josefk]

I can't help on your troublesome X Sge (i'm still in the shallow end wearing arm ends w.r.t. doubles) but i do understand BUP to be a Burnham extension from this useful summary at https://www.handprint.com/ASTRO/bineye2.html

It sounds like you've had a productive few nights. 

Life intervened but i was hoping to be in Cygnus or Cassiopeia searching STF doubles myself last night (i've prepared Struve based  lists for these two areas for brighter nights over the next few weeks).

[Nik271]

A great haul of doubles, well done! The little Skymax 127 is a double star specialist, 1.8'' separation is not even its limit. For harder but perfectly doable workout for the Mak (and the observer!)  I recommend Pi Aquilae or Mu Cygni. 

I suspect stelledopie is correct and X Sge has companions too dim for 120mm aperture. I will have a look next clear night, (which might be tonight fingers crossed)

[Johnny81]

41 minutes ago, Nik271 said:

A great haul of doubles, well done! The little Skymax 127 is a double star specialist, 1.8'' separation is not even its limit. For harder but perfectly doable workout for the Mak (and the observer!)  I recommend Pi Aquilae or Mu Cygni. 

I suspect stelledopie is correct and X Sge has companions too dim for 120mm aperture. I will have a look next clear night, (which might be tonight fingers crossed)

Thank you for your comments. Yes - I think I can push the mak more. I think I have been put off in the past due to some failures of splitting really close stars. However, I think that might have more to do with magnitude difference than separation. I shall keep going - it will be many years of work going through the Struve list and I am going to have to split a few more close pairs!

[lunator]

For data on doubles you need to use the Washington Double Star Catalogue or Setlla Doppie.

I've had a quick look at BUP203 the b component is mag 13,the c is 12.97 so given the brightness of the Moon they probably would not be visible. 

When I was observing on the 14th with a 250mm scope getting below mag 12 in Ophiuchus was very difficult. 

Cheers

Ian

[Johnny81]

Continuing in Cygnus - 17/09/2024

127mm Maksutov-Cassegrain on AZ4 alt-Az mount. 

Another evening of good seeing with the moon low behind my house till about 10pm...

Mu Cyg (STF 2822): Nik271 set the challenge and... couldn't see a secondary at all at x187. Shame because we don't know how long this decent seeing will last. Another time perhaps.

49 Cyg (STF 2716): Tricky although only a 2.5 mag difference at 2.8'' separation but glimpses of secondary at approx. PA: 45^o.

STF 2702: Faint close pair (3.14''), secondary at approx. PA: 200^o.

STF 2624:  Easy split at 1.9'', white primary and secondary looked yellowish. AC component much wider at approx PA: 320^o (almost above primary)

STF 2663: Near Gamma Cyg. Slightly fainter secondary 5'' away from the primary at approx. PA: 300^o

STF 2666: Near Gamma Cyg. Tight 2.8'' pair , a few other dimmer stars in the region. A pretty little area of sky, worth a look if you haven't already.

The swan was getting up towards the zenith by now so we're in neck breaking territory......

STF 2588: Wider 9.6'' equal whitish pair 

Delta Cyg (STF 2579):  Reasonably easy at x150 and x187. 2.5'' separation and looked like a little pimple on the airy disk.

Psi Cyg (STF 2605): An easy 2.86'' split at x150, the secondary at approx. 180^o

STF 2681: 10th mag secondary not seen even with a 6.8'' separation,  but a much wider companion (38'') observed at PA: 180^o.

STF 2658: Faint close secondary approx. PA: 90^o from primary

STF 2671: I noted a golden close secondary at 3.5'' but easily split at x150.

STF 2611: Equal whitish pair 

STF 2486: Fairly close (7'') equal white pair

STF 2576: Another equal pair which looked rather dim, notably looking on top of each other at x150/x187

Edited September 18 by Johnny81