Epsilon (ε) Lyrae
RA: 18h 44.3m Dec: +39° 40′
Epsilon-1/AB (Σ 2382) (H II 5) HIP: 91919 SAO: 67309
Magnitudes: 5.15, 6.10
Position Angle: 346° (WDS 2013)
Spectral Type: “A” is A3, “B” is F0
Distance: 162 Light Years (Simbad)
Epsilon-2/CD (Σ 2383) (H II 6) HIP: 91926 SAO: 67315
Magnitudes: 5.25, 5.38
Position Angle: 78° (WDS 2013)
Spectral Type: “C” is A^, “D” is F7
Distance: 160 Light Years (Simbad)
June 22nd, 2010
After being lured out several nights for the past week by hopes the clouds would give me a break for half an hour or so, I decided to give it another try tonight. The sky was about seventy percent overcast, so at least there was a slim hope. And, like the last few nights, as soon as I was set up and ready to go, the sky gods drew their blanket of clouds back across the stars, chuckling to themselves as the last few bright spots disappeared. But, with a cup of tea in my hand, the ocean humming away in the background, the moon playing hide and seek in the trees to the southwest, and the temperature a mild fifty-five, I decided to stay put and just enjoy the night.
After I sat there for about thirty minutes, the clouds thinned enough that I could see Vega, so I pointed the finder on my 90mm refractor at it and poked around until I found Epsilon (ε) Lyrae. Now, if you’ve never done this — and this was my second time — you’ll be amazed both at what you can see and how stable the atmosphere is. The overcast has to be thin enough that you can see at least first magnitude stars, and the clouds should be moving at just a crawl — but — under these conditions, the seeing can be very good. My first view in the ninety was with a 20mm TV Plössl (46x) and I could just begin to see some separation between each of the two stars in Epsilon-1 and Epsilon-2. Replacing that with a 15mm, which increased the magnification to 61x, they were clearly separated.
So, with the evening being so pleasant, I just watched the four stars as the clouds drifted by. Sometimes they would almost disappear from view, other times they would suddenly brighten as the clouds thinned out. Most of the time, they were about halfway in between. But the seeing was as steady as a rock the entire time, so it was pleasant to just look at the two doubles staring back at me without quivering in the least.
June 23rd, 2010
Now, this is more like it! A totally clear sky and not a breeze anywhere near! My plan tonight was to sample of few of the sparse offering of doubles in Ursa Minor, but I noticed the sky was much darker to the northeast, so I pointed my scopes at Epsilon (ε) Lyrae again. And, believe it or not, I spent the better part of an hour here and even after that length of time, I had to force myself to move on to something else.
Tonight, I had a 105mm, f/15 refractor aimed at Epsilon (ε), and riding on the back of the long refractor was a miniature copy of it, a 60mm f/16.7 that I put together from parts. The moon was out and about ninety percent full, but it was hugging the southern edge of the sky, and most of it’s glare was blocked by some tall fir trees. So even though it was bright, it was behind me and low enough not to be scattering light all over the sky.
Now, as satisfying as the previous night had been, tonight’s first glance into the 18mm (83x) eyepiece in the larger refractor left me frozen in place — although I think an involuntary expletive deleted might have slipped from my lips — but I was so stunned, I can’t honestly remember. In the eyepiece, the sky was pitch black, and the four components of Epsilon (ε) Lyrae were four bright white pin-points of light that looked as if they were hovering above the blackness, and scattered at the edges of the eyepiece were fainter stars that accentuated the three dimensional effect. After the haze of the previous night, and with the larger scope gathering more photons, plus the wider field of view in the eyepiece, the image was absolutely razor sharp and vibrant. Multiply very pleasing by a factor of twenty and you get close to what I saw.
But it got even better when I compared it with the 60mm scope. I put a 20mm TV Plössl (50x) in that one and saw two white pinpoints on each side of the eyepiece that were touching, so I replaced it with an 11mm version of the same brand (91x) and could begin to see some black sky between them. A 9mm UO Ortho (111x) put a definite border of black sky between the close components. As satisfying as it was to split Epsilon (ε) with a 60mm scope, I kept going back to the view in the larger scope because of the three dimensional effect. There was such a contrast in image brightness between the two that I just couldn’t resist looking at the view in the 105mm again and again and again. The difference in light gathering ability of the two scopes was a huge factor in enhancing the view in the larger one.
And once again the seeing was very stable, so I decided to push the magnification on the 60mm to see what it could do. I thought I would go for broke and jump to a 4mm Astro Tech Plössl (250x), but it was just a bit too much. All four stars were there, but the focus was very soft, although for very brief moments, they would snap into focus. I moved back to a 6mm AT Plössl (167x) with much better results — four nice round globes with just a bit of unevenness around the edges, surrounded by those mesmerizing diffraction rings. Not one to give up quickly, I replaced the six with a 5mm UO Ortho (200x) and found the view was about the same. But the highlight of the night was when I removed the 5mm and put it in the larger scope, which gave me a view at 300x that was very similar to the one in the 60mm, only much brighter.
And then I remembered there was another “double-double”in Lyrae, so after more than an hour of very pleasant and rewarding viewing, I pointed my stack of scopes in a more southerly direction.
(WDS data updated 9/9/2014)