Iota Cas

[themos]

(click to enlarge)

I will add the necessary details later!

[supernova]

nice one matey.

[themos]

The same view from Stellarium

(click to enlarge)

[themos]

A crop from a single frame from the AVI capture.

I used the 12" Dobsonian for this and the ToUcam. Barlowing proved too tricky, I couldn't find the target.

K3CCDTools calculated the image scale at 0.77" per pixel. Under 8x digital magnification, I counted the pixel separation of the orange and white blobs, it came out at 8 pixels in one direction and 6 on the other, giving a Pythagorean 10, which works out at 7.7 arc-seconds. The white blob shows evidence of being elongated, perhaps something like 5-6 pixels longer in one direction than the other. That gives a centre separation of the two putative constituent blobs of about 2.5 pixels or 2 arc-seconds.

(click to enlarge)

[barkis]

That is great stuff Themos. I have just had a look at Burnhams on Iota Cass. Closest pair form a binary in slow retrograde motion, with a period of about 840 years., according to a 1962 orbit computation by Heintz. The semi major axis of the orbit is 2.3 arc seconds, and the eccentricity is 0.40. Apparently, astrometric measurements indicate that another much closer star is present, with a period of about 52 years.

The third visible component is at 7 arc seconds, and is a physical member of the system, but has shown no definite relative motion since discovery by F.G. W. Struve 1829. The period must be at least several thousand years.

The projected separations are AB = 115 AU,s AC = 350 AU,s. The primary of the system, is a spectrum variable, with a period of 1.74 days.

I hope you don't mind me adding this information to your post, I just thought it would bring home some realization to what these specs of light you have imaged, represent, and be of interest to some readers. I merely copied the info from Burnhams. I don't pretend to understand all of it, but I do have a great interest in multiple star systems.

Ron.

[themos]

Thanks for adding the Burnham info. I just had a look in recent preprints to see if there's any interest in Iota. Most recent research is focused on "Cas A", a supernova remnant. It does look extraordinary in Hubble pictures.

[barkis]

I guess most of the interest in Cass 'A' centres around it being a strong radio source. I have seen a Hubble image of it, and you are right in saying it looks extraordinary. I always thought it was Tycho Brahe who first observed the Supernova that resulted in Cassiopeia A.

I will have to go and do some research.

[lunator]

Hi Thermos

nice catch.

The current measures based on the WDS are

STF Aa-B 2.9" Mag 4.63/ 6.92

STF Aa-C 7.6" Mag 4.63/ 9.05

Rgds

Ian

[david scanlan]

I was in the iota cassiopeia region last night actually :-)

tracking down a couple of variables that I observe on my programme

Nice images....I dont think theres enough imaging of double stars taking place to be honest so its nice to see

Dave

[lunator]

David

Myself, Thermos & SteelRat do undertake DS imaging.

Most imagers of double stars use the images for measurement services.

I measure visually and only photograph doubles for fun.

Cheers

Ian

[david scanlan]

Thats great to hear

Keep up the good work

Dave

[david scanlan]

How do you measure the seperation of doubles?

I have read a bit about it but its one of those things where I tend to see maths involved and then my brain kinda melts

Dave

[cygnusx1]

Themos, i'm very curious - at what mag and f/l was that imaged at?

According to Stellarium the fov in that image of yours is about 0.02 degrees!! :shock:

Surely no ep or amateur scope can give that sort of resolution?

[themos]

I wrote earlier that I used the ToUcam and the Skyliner (fl=1500mm). Scale works out at 0.77 arc-seconds per pixel. FOV is about 8x6 arcminutes.

This is a frame from the capture:

The first image I posted was the result of the stacking but enlarged massively so that the shapes and colors can be seen.