3 stars in Hercules

Hello, everyone.

Haven't the last 2 nights only been brilliantly clear (in Dublin anyway)? Over both nights, I was out observing for a full 5 hours with my 158mm apo. I found it irresistible to turn off the TV (there is nothing on anyway) and go out and enjoy what the sky has to offer on both Monday and Tuesday nights. (17th and 18th August)
1. On Tuesday night, the sunset time was 20.47. I found Arcturus and Vega at 20.25 and 20.40 respectively.
2. Right beside Vega is, as we all know is the famous double -double Epsilon Lyrae. It is so easy to see both pairs split at 112X.
3. High in southern sky is Rasalgethi (Alpha Herculis). Valerie was with me as we figured out its colours. I was somewhat surprised to see both components separated at 40X. But to study the colours, I quickly increased to 112X, 140X and 167X. We both agreed that A is orange with a tint of red. B only showed up as blue. (Sorry Mike). Some observers think it is turquoise or amethyst. But to us, it's blue. My apo loves to kill some colours. So I have yet to see a "green" star.
4. Next up is a really tough double star: Zeta Herculis. There have been some discussions on www.cloudynights.com about how difficult is it to split. When I got up to 280X, I wondered was I wasting my time. However, I am armed with 3.5mm Nagler which gives me 320X and I split it with this power. This double is the fastest moving double I have ever checked out. The B component orbits the A component once every 30 years! Imagine the speed of that! I did check the website stelledoppie.goaction.it before hand. Currently, A is 3.0, B is 5.4. The separation is 1.2 arc seconds and the Position Angle is 134 degrees. That is just above 3 o'clock in the eyepiece. I am very pleased I had the sky conditions to resolve Zeta Herculis. Has anyone else had a shot at this double in the past?
5. This next star which is an orange carbon will test your star hopping skills as it is almost overhead. You must travel through the Hercules Keystone asterism and move in a northwesterly direction almost into southern Draco. The reward though is quite good. RR Herculis is a faint but quite strong orange variable star (N class). Its magnitude varies from 8.8 down to 13.5. At present, I see at magnitude 9.0, and I have recorded it on AAVSO. There is a K class orange star right next to it with a magnitude of 9.3. RR is a more stronger orange. Why not check it out? I did discover that as I increased the magnification up to 167X, the orange colour got richer.
6. On Tuesday night, what turns out to be my 32nd carbon star, was a bit of a flop. Where is the orange colour of SAO 106516? The star is in Delphinus just a couple of degrees north of the famous double Gamma Delphini. SAO 106516 is right next to a yellow star SAO 106520. Guide 8 initially describes 106516 as a K class star; but then later in the "more info" link describes as an R class star -which means it is a weaker carbon banded star. However, I must say that it is the easiest carbon star to find.
7. Finally, I had to enjoy Gamma Delphini and Struve 2725. Even at 112X, both the bright and faint double are in the same field of view -nice!

Thank you for reading.

Clear skies,

Aubrey.

Hello Aubrey, As it happens I was out last night as well beautiful night, and Zeta Hercules
was one of the doubles I looked at. Imanaged to split it at 275x with the 6 inch
reflector both stars looked white to me. I also split mu cygnus at 275x but no
luck with Lambda Cygnus.

Pat.

Hey, my man -welcome back.
I haven't heard from you for such a long time. Life gets busy, I suppose.
It's great to hear what you have been up to astronomically speaking, Pat.
How did you know about Zeta Herculis -I wonder if is has a name? I personally only came across it in the last 2 months. I never thought it was a double. I have always been keen on nearby M13 and M92.
And surprise, surprise, I have never observed Mu Cygni. It is listed in Burnham's books. So I might have a shot at some time.
Lambda Cygni is extremely tough. 2 years ago, I split at 320X; and then last year, I split it at 280X. Maybe it has got a bit tighter recently.
But I must congratulate you on splitting Zeta Herculis -well done. It's great you still have the enthusiasm in double stars.

Clear skies to you, Pat.

Aubrey.

Hi Aubrey, I first split Zeta last year, I believe it was Neil English who put me on to it.
I believe it is sometimes called Ruticulus althought there is some debate over that.
I have split Lambda cygnus last year on a night of fantastic seeing but not since, if
only we had more clear nights.

Pat.

I have heard of Neil English. It was good of him to give you Ruticulus to test your optics.
Lambda Cygni magnitudes are 4.7 and 6.3. The separation is 0.9" and the PA is precisely 0.

I am in the mood to check out Mu Cygni next clear night -whenever that is.
By the way, we do need windless nights to use high magnifications on these tough doubles -I am sure you know that. Last Monday night was perfectly calm. But Tuesday night there was a bit of a breeze.

Clear skies,

Aubrey.

Aubrey, another star I am working on at the moment is 68 Hercules magnitudes 4.8 and 10.2
with a separation of 4.2, its tricky because of the difference in magnitude I have split it once
about two weeks ago but not since have a go at it when you get a chance.
I remember the night I split lambda cygni I was very excited I even wakened up Mary my wife
to tell her the good news, it was not well received as it was about 1 in the morning, but it was
the first time I had split a double under 1 arc second, and still the only time.

best wishes

Pat.