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Old 11-08-2018, 09:04 AM
Tropo-Bob (Bob)
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Join Date: Sep 2013
Location: Cairns
Posts: 1,584
My observations

I viewed these on the evening of 8th August. Alpha to Delta Aql were visible to the eye without difficulty, Epsilon was visible with difficulty.

I used my Orion 80mm Triplet (FL 480mm, on an AZ mount.) For EPs, I mainly used a 24mm Panoptic, 5.7 & 15mm Radians, and a 3mm Long Pern.

I did return to this on the evening of 10th August to split one double that the 80mm could not resolve.


Objects of interest.

Eta Aql. A well know Cepheid variable. Its magnitude ranges from 3.5 To 4.3 over 7 days...
I found this easily, as it is in a direct line from Eta to Delta. I estimated its magnitude to be similiar to Beta Aql, which is mag 3.9.

Pi Aql. A close binary. (Separation 1.4", mags 6.3 &6.8)
I returned to this last night (10/8) with a larger telescope after failing to split this double on 8/8 with an 80mm scope, using 160x

I split this with 140x using a Meade ED 127mm (F9). I correctly estimated the Magnitude difference between the two stars as 0.5mag. I also took a stab at the PA and thought it was roughly 90 degress. Since it is 106 degrees, I was roughly right. Lol.

I actually first split them with a Vixen 8mm LVW EP. They appeared tight, but cleanly separated. Then I tried a 7mm Delite (160x), which resulted in a slight drama. The split was vague and not nearly as clean. This is when I noted the PA. Finally, I used a 6mm Radian (190x) and the split again looked clean. I love the lightness of the Delites compared to the Radians at higher magnifications, but this is the second time that I noticed a Radian EP showing better detail than a Delite of similar FL.


15 Aql. A colourful double.
Even at 20x, the split looked wide. However, this is a beautiful, colourful double, which is located almost on the boarder with Scutum.
The colours looked to be a light-orange primary, with the companion being red. The pair was about 1 mag difference in magnitude. (Note: Difference is actually 1.5).


57 Aql. A showpiece double near the boarders with Capricornus & Sagittarius.
A striking pair of bright, white stars that were separated with 20x. The stars were only slightly unequal in magnitude.

Struve 2644. Location 20h.12; + 0.52. (Separation 2.6", mags 6.9 & 7.1)
A pair of near equal stars split with 95x, though the view was better using 160x


The Main Stars.

Alpha Aquilae (Aql)... Altair is only 17 LYs away.
Appear to be a slightly creamy white.

Beta Aql.
Light orange or perhaps a deep yellow. Sometimes the longer I look, the more uncertain I become.

Gamma Aql.
Gamma is somewhat brighter than Beta. It appeared orange.

Delta Aql.
Appeared white.

Epsilon Aql.
Appeared orange.
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