Lambda & Delta Cygni

[Stu]

Thanks - not quite a split though as the snowmans head still appears joined to his body !

I'm sure the snowman is quite happy about that arrangement!! :-)

Some would class that as split wouldn't they? I stick with clear black between them as my definition; it sounds like you do too.

Sent from my iPhone using Tapatalk

[Special K]

Is the seperation of Delta Cyg 2.5 arc seconds? And given the magnitude of the double is it awash in the diffraction ring of the primary star? I was having trouble last night whereas the double double in Lyra wasn't an issue and they have about the same seperation according to my atlas. However, the Lyran stars are roughly the same magnitude so easy to spot. Maybe I was looking in the wrong place, I'm lost without my old red dot finder!

[Stu]

Is the seperation of Delta Cyg 2.5 arc seconds? And given the magnitude of the double is it awash in the diffraction ring of the primary star? I was having trouble last night whereas the double double in Lyra wasn't an issue and they have about the same seperation according to my atlas. However, the Lyran stars are roughly the same magnitude so easy to spot. Maybe I was looking in the wrong place, I'm lost without my old red dot finder!

SkySafari quotes it as 2.7" separation. I didn't find it close to the diffraction ring, it was quite clear. A lovely pin point of light :-)

I agree that the differing brightnesses do cause issues though.

Sent from my iPhone using Tapatalk

[John]

It's the uneven brightness that makes Delta Cygni the challenge it is

Sirius is the ultimate in this respect where the primary is massively brighter than the secondary but the actual gap between them is currently a relatively easy 8-9 arc seconds.

Personally I reckon that unequal brightness close double stars are a great test of scope, conditions and observer