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4 July 2004: Starhopping Lyra



Last night I observed some interesting double stars, an open cluster and a planetary nebula with my 15x80 binoculars and the Sky-window. All objects are situated in Lyra. I started around 22.00 hours 22 and ended the session around 23:45 UT. I used the SkyAtlas 2000 to locate the objects.

Lyra

Finderchart for the objects I observed, generated with SkyTools 2 by Capellasoft.
The three large circles represent the binocular field of view of 3 to 3.5 degrees


I started my observing session around 22:10 UT with

Vega (Alpha Lyrae), the brightest star of the summer triangle: Vega, Deneb, Altair. Vega is a magnitude 0.03 star of the spectral class A. It appears just plain bright white through the binoculars. A beautiful sight! From Vega I moved to the northeast, to find Epsilon 1+2 Lyrae, the famous double-double. Through binoculars the Epsilon 1 and 2 looks like a nice pair of equally bright stars, separated about 3.5’. Both stars appear to be white, their magnitude somewhere between 5 and 6. Epsilon 1 and 2 are both double stars themselves. That’s why they are called the double-double. You will need a telescope and use medium to high power to split them.

When having Vega and Epsilon together in my field of view (3.5 degrees), I noticed another interesting double star to the southeast of Vega. This proved to be Zeta Lyrae. The two components of Zeta Lyrae are separated by 45”. There is a clear difference in brightness between the two stars. One has a magnitude of 4.3 while its companion is of magnitude 5.9. The brighter of the two, an A0 star looked more yellowish than its dimmer companion, a F0 star, that looked whiter. The strange thing is that the colors should be the other way, the F0 star should be more yellowish than the A0 star. Probably this is caused by the difference in magnitude and the quality of the optics used.

From zeta I moved two degrees to the south to stumble upon another beautiful double star for binoculars, Beta Lyrae. The two components A and B are separated by 45” in PA 149 degrees. The A component is of magnitude 3.4 while B is of magnitude 8.6. Both appear to be white. While looking at Beta Lyrae I suddenly noticed a smudge of light to the east of Beta Lyrae. The smudge was only visible with averted vision, and was definitely not star-like. This had to be M 57, the Ring Nebula. I never saw this object through binoculars before, so I didn’t expect it to see it tonight with only a moderate seeing and no real sky darkness. A very nice surprise! It looked like a small grayish circle of light.

From Beta Lyrae I moved in northeastern direction for 2.5 degrees to find Delta Lyrae 1 and 2. These two stars are separated by 10’. Delta Lyrae 1 is a B3 bluish-white magnitude 5.6 star. Delta 2 is an orange looking M type star of magnitude 4.3.

To the west of Delta 2 I see 4 fainter stars forming a kind of trapezium. Together with Delta1/Delta2 they form a small open cluster, Stephenson 1. In larger telescopes Stephenson 1 shows about 15 stars scattered over 20’ to 40’. With Stephenson 1 I ended my observing session around 23:45 UT.

Stephenson 1

Sketch of Delta Lyrae 1 and 2 / Stephenson 1




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