Epsilon Lyrae - The Double Double

[davhei]

Epsilon Lyrae is a favourite system of mine and one I’m fond of observing. I was again out to view Jupiter and ended the session by sketching the ”double double”-system.

I believe part of the fascination lies in its ability to aid in visualising astronomical distances. According to my understanding e1 and e2 mains are separated by 0.16 ly and the components of each main by 140 AU. The whole system being 162 ly distant. It bridges interstellar distances and solar system distance scales. Very cool.

Bright summer nights here in the north so few background stars were visible, only one in fact, but it helps determine orientation in the drawing I think.

Pretty happy with the separation, angles and brightness of the component stars. Seemed fairly true to the scope view I felt. Not entirely sure about the west/north notation though, but as a rough indication it works.

 

[wxsatuser]

Nice sketch.

Think north and west could come round a tad clockwise.

[davhei]

53 minutes ago, wxsatuser said:

Nice sketch.

Think north and west could come round a tad clockwise.

Thanks! You are probably right. I forgot to mark it at the eyepiece and had to add it at home. Was pretty tired at that point 😴

[davhei]

By the way. I got confused when I set out to determine which pair is e1 and which is e2. Looking in my copy of Interstellarum e2 is noted as the northernmost pair.

Other sources and the angle measurements of the component stars firmly indicate e1 as the northernmost pair.

Is this an error in the Interstellarum atlas?

 

 

[wxsatuser]

Cambridge double star atlas has e1 as northern most.

[davhei]

33 minutes ago, wxsatuser said:

Cambridge double star atlas has e1 as northern most.

I suppose with Interstellarum having so many stars it is unavoidable to have a few mistakes. Still, it is a pretty famous object at that.

[Lurcher]

Nice sketch and post. I've started to really appreciate double stars since joining Stargazers Lounge and seeing people's reports and drawings of them like this. I've seen the double double, and just about separated them but perhaps never as clearly as I would have liked. I'm hoping it's down to atmospherics and they will appear sharper under darker winter skies maybe, so I will keep going back to them.

Thanks for posting.