Multiple stars, 17 Lyrae and Aquila.

slim chance to get there before the huge Moon bleached out the sky.Aquila is well placed for comfy seated for observing. Altair is a fine wide binary. Attention to some multiple and binary stars. It’s a wonder that larger apertures can catch faint magnitude stars. One numerical change in magnitude is a change of x2.51 in magnitude. However this is exponential, 2 magnitude difference is 2.51 squared ,3 is 2.51 to the power of three.

17 Lyrae gives a wonderful high power view of this multiple. The companions are a manageable search.(SAO 67835) A is 2.2 x Sol diameter.

23 Aquilae is an eruptive variable giving a yellow and astounding blue companion. A huge A has a diameter of 22.3 Sol. Separated by 364 AU. (SAO 124487)

28 Aquilae is a pulsating variable, the A being x3.6 Sol diameter.(SAO 104722)

Now for a very very fast moving star, 31 Aquilae. There are 4 stars here not gravitationally linked . Herschel did not include it in his list of doubles as A was well away from other stars.(SAO 104807)

Hoping next time out to catch the low field view that includes Σ2547, Σ2545, LV21 and Σ2541. Clear skies ! Nick.

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