"ruler" function, distance measurements

[Forum_2018]

Hi,

How do You measure the distance between to arbitrary points in a platesolved image?

/Rudi

[Forum_2018]

Hi, select the two stellar objects, then from the Stars Window, right-click and Separation.

[Forum_2018]

Thanks for the answer Fabio. Yes - I know about this "star seperation measurement", but what about between two "arbitrary" points?
Say I want to measure width of a galaxy or length of comet tail.
If You could start a "rubber ruler":
1) start "rubber ruler" measurement
2) click at one point
3) move mouse around and a line is drawn from first click point to cursor, showing arc distance and direction.
Perhaps it could be added to a suggestion list?

[Forum_2018]

Hi, select point 1, point 2, then Menu View / Profile / Free.
In the title of the Graph: L = Length and A = Angle. If image is platesolved then L and A are shown also as degrees and correct position angle.
1-2-3) This can be done clicking the Profile icon on the left toolbar, without selecting the two points. But I think that it's more precise selecting the two points before.

[Forum_2018]

Hi - thanks Fabio. So it is possible. Actually I think that an astro friend showed me this way of measuring once, but I must have forgotten.
I'll write it in my notes. Still, it's a bit of a detour to measure arc distances and angles, I still think a dedicated ruler would be nice
But again- thank a lot for your quick response here.

[Forum_2018]

Hi

Just on this issue, how do you select the two stellar objects? Whenever I go to the Stars window, the Separation option is always greyed out.

Also, once the Stars window is populated, how can I copy the table and paste it into something like Excel? Whenever I try to Select and Copy, not all of the columns come across.

Thanks

[Forum_2018]

Hello,
in the image, just left-click on the two stars.
Then in the stars window right-click for the context menu.
All fields will be copied except the ra/dec in HMS format. By the way, in excel you could prepare a row which calculate them from the numeric RA/DEC that is provided, in degrees.
To export the RA/DEC also in HMS format the only solution is to save the list as text.

[Forum_2018]

Fabio, Sorry, but I seem to be having some trouble here.

So I left click on a Star and it is added to the list in the Stars window. I left click on a second Star and it is added to the list.
Then I right click anywhere in the Stars window and a list of options appears - eg Edit Star, Delete, Find Stars, Separation.

But the Separation option is greyed out.

Any suggestions on what I am missing? Attached is a screenshot of the Stars list.

Thanks
Darrell

[Forum_2018]

I think you should only have two stars in star list to use separation.

[Forum_2018]

einari. Thanks. You are right. Two stars in the list and I get Separation.