Zeta Herculis at last!

[Nik271]

 

Hi, I just want to share my excitement from last evening. It was very still and a bit misty, which to me indicated that  the seeing may be good. And I was not mistaken!

I had put my Skymax 180 out of the shed and by 8pm was ready to go.  I started with Jupiter because it was as high as it gets and was treated to a decent view at about 150x with the GRS clearly visible and even some other 'wrinkles' in the bands just on the edge of visibility. 

With Jupiter going down below a roof I moved to Saturn. Even better: the Cassini division was easy to see and I could trace it around most of the ring. Some banding of the planet was visible and the shadow it cast on the ring. I was pleased to spot Rhea between Saturn and Titan and I spent some time trying to spot other moons but couldn't. I have only seen Thetys before.

The good seeing reminded me of unfinished business: Zeta Herculis. I tried for it in June but never got a change with the weather.

Tonight was the time. Zeta Herc was easy to find, the second brightest in Hercules and it was still at 50degree altitude. I switched to a 6mm eyepiece giving 450x hoping for luck and there it was: a small yellowish dot just on the edge of the first diffraction ring of the primary!  Wow! The position was East and slightly South. I spent 15 mins looking and the dot came and went around the shapeshifting diffraction ring. Gradually it got worse, perhaps the star lost altitude or the seeing deteriorated.

This morning I checked with stelle doppie and it gives separation of 1.36'' at 111degrees https://www.stelledoppie.it/index2.php?iddoppia=67135

which fits with my observation 🙂

This double system is 35 light years away with a period of 34 years and semi-major axis of just 15AU.  I'm thrilled to be able to see something at these distances! The separation will grow to about 1.5'' over the next 5 years.

Since I was in Hercules I had a quick look at M13 (with 15mm) but it was not the best view I've had, I guess it was not yet fully dark.

I had some time to kill waiting for Mars to show up so I took a look at the Ring nebula in Lyra. It is always good in my scopes. I even tried 6mm at 450x. The ring filled the view and I could spot irregular glowing bits around the edge. I tried to see the central star but no luck. Well you can only ask for so much in a single session.

At 10pm Mars was poking over the fence so I looked at it with 9mm (300x) and a neodymium filter to cut the glare. It was still low in the sky and dancing a bit but I can see the polar cap, Syrtis Major next to the west limb and Sinus Sabbaeus very prominent in the centre. 

My eyes were getting tired and dew was settling heavily on the Mak - time to call it a night. One of the best I've had under the stars  🙂   Thanks for reading and clear skies!

[Sunshine]

Congrats on Zeta! I myself have spent the better part of the summer trying to split Zeta Herc. Every clear night I’d give it a shot, only lately, just last week did I manage to see the two stars with black between them, seeing was exceptional that night.

[John]

Congratulations on this challenging binary !

I first managed it a few years ago with my ED120 refractor, sketched it and then repeated the sketch earlier this year. The movement in the position angle is quite marked:

 

[Nik271]

Nice sketch, John! 

Indeed the secondary was almost opposite the drift direction and was just next to the first diffraction ring. There were long moments when I can see it separated from the airy disc, a tiny yellow-white dot. 

I must have hit some clear period in the seeing in the early night yesterday. It's so hard to predict when it's going to be good. 

 

[RobertI]

Nice catch. It’s a tricky one to be sure. With my 150PL I had to go to 540x to see it for sure!