Lovely Aql Double in Wide Arc of Stars

[cloudsweeper]

7.15pm, clear sky, ED80 ready waiting for me.  Nothing planned - just fancied sweeping this fabulous 'scope around the sky.  Aimed south, up a bit, and spotted a pair which were conspicuously orangey.  Stellarium told me they were 15 Aql, a double with an easy 39" separation, sitting in a lovely arc of stars in a huge 5.7deg of field and x11 mag.

The colour was clearer at x24.  Sources describe it as yellow/blue or yellow/red, but it was orangey/orangey to me - and very clear and attractive.  Mismatched.

14 Aql is also a double, but clouds prevented further investigation at only 7.35.  

Another case of grabbing any opportunity.  Brief, yes, but very satisfying, and recommended - especially to doubles fans!

Doug.

[StarryEyed]

Doug.

"orangey/orangey" I say things like this all the time and constantly get pulled up on them at work. I'm happy happy to see I am amongst like minded people.

orangey/orangey....

Kevin

Edited October 16, 2019 by StarryEyed

[cloudsweeper]

Update:

15 Aql is an optical (line of sight) double rather than a gravitationally bound system, and is listed in Haas but not the Cambridge Atlas.  No less attractive for that mind you!

14 Aql is not in either volume, but Stellarium has it as a double.  I believe it is a spectroscopic double, so cannot be split visually.

Doug.

[ @StarryEyed - Kevin - I was undecided between that and orangeish/orangeish!]

[Stu]

Skysafari describes one component of 15 Aq as Orange and the other as Orange-Red, pretty close in colour visually so I'm not surprised tou didn't pick up much difference.

14 seem to have a separation of 0.1" so a touch on the tricky side!!!

[Geoff Barnes]

A bit off topic and apologies for that, but it was the "orangey orangey" that caught my attention. I was double spotting t'other night and came across 61 Cygni in Cygnus for the first time, a lovely double with 30" separation that to my eyes were both very orangey orangey. 

I was wondering how much of their bright orange appearance was due to their very low altitude, just 12 degrees above our northern horizon, so a lot of atmospheric murk to shine through. They would be presumably very high up in UK locations, are they still "orangey orangey" up there?

[cloudsweeper]

34 minutes ago, Stu said:

Skysafari describes one component of 15 Aq as Orange and the other as Orange-Red, pretty close in colour visually so I'm not surprised tou didn't pick up much difference.

14 seem to have a separation of 0.1" so a touch on the tricky side!!!

Thanks Stu - glad I got it right.  I just chanced on the pair, and they stood out appealingly.  I should refer to SkySafari more often.  14 Aql - yes, unsplittable visually - according to the approx. formula, you'd need an impossible mag of between x2500 and x3000 to crack that one.  Spectroscope required!

@Geoff Barnes - 15 Aql was at about 28deg.  I believe perceived colour depends on several factors.  61 Cyg is at about 75deg.  I'll take a peek next time out.

Doug.

[Ouroboros]

@cloudsweeper I liked the phrase "nothing planned". Often the best way start an observing session. You stumble across some of the best stuff that way. 

[cloudsweeper]

10 hours ago, Geoff Barnes said:

A bit off topic and apologies for that, but it was the "orangey orangey" that caught my attention. I was double spotting t'other night and came across 61 Cygni in Cygnus for the first time, a lovely double with 30" separation that to my eyes were both very orangey orangey. 

I was wondering how much of their bright orange appearance was due to their very low altitude, just 12 degrees above our northern horizon, so a lot of atmospheric murk to shine through. They would be presumably very high up in UK locations, are they still "orangey orangey" up there?

OK Geoff - just been out and saw 61 Cyg (Piazzi's Flying Star) - quite high in the sky - very like 15 Aql, arguably a bit more orange, and a closer match.  Easy split at x20 (4.10deg).  A beauty - don't know why I haven't targeted it before!

Doug.

[Stu]

I did some searching and thought this might be useful, these are the colour indices for the stars being talked about, and some references.

T Lyrae 5.5 (Very Red!!)

Garnett star 2.24 (Red)

Betelgeuse 1.74 (Orange red)

15 Aquilae 1.11 and 1.54 (Orangey Orangey 🤣)

61 cygni 1.07 and 1.31 (same again?)

Vega 0.00 (White)

Bellatrix -0.14 (Blue white)

Sigma orionis -0.24 (Blue)

[cloudsweeper]

9 hours ago, Stu said:

15 Aquilae 1.11 and 1.54 (Orangey Orangey 🤣)

61 cygni 1.07 and 1.31 (same again?)

Great Stu - is my description now official terminology?  😆

Doug.

[mattjanes100]

Nice to grab an opportunity, lucky to spot a gap in the clouds and rain!

I will add this to my next session, intrigued by the orangeness...

[Paz]

On 16/10/2019 at 09:12, Stu said:

Skysafari describes one component of 15 Aq as Orange and the other as Orange-Red, pretty close in colour visually so I'm not surprised tou didn't pick up much difference.

I had a look at the hr plot and both components are close together within the K class.