Celestia Forums

Has anyone out there ever hooked celestia up to a Goto Scope?

I've always had a bit more trouble than I thought I should to use Celestia in a planetarium sort of way, though I know a few specific keystrokes can accomplish it relatively well.

It got me thinking, if there were an interface for entering a specific GPS location and pinning the view to it, it should be possible to calculate positional information, RA and DE, for an object that's selected relative to that point.

I know Celestia isn't "The Sky" type planetarium software, but it's SO easy to use and most astronomy software is just the opposite. Plus how cool would it be to have Celestia running - then point to an object and click "Telecope Goto" and have the scope go there. Then a click on "Goto" and literally fly to the object to show it to people... 'would be freaking cool, especially during transits, occultations or eclipses!

This can't be the first time it's been brought up but I couldn't find another thread for this.

Anyway I don't know enough about what this would entail but I thought it be interesting to discuss.

Any ideas? is it totally insane?
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Jonathan Mickelson

I found this thread for example: http://www.shatters.net/forum/viewtopic.php?t=59

steffens

That's funny a search in the search feature of the forum wouln't come up with anything for the word telescope. But I "was" reasonably sure I'd read a similar post years ago. The thread you quoted fits the bill... Thanks...

Would still be cool!

That is strange.

I used search just now, looking for telescope, and got 247 matches.
telescope AND control yielded 10 matches

Maybe you did a typo?

jwmickelson wrote:
Would still be cool!

I am not so sure! See my contributions in the thread quoted by Steffens. For 11 1/2 years I was involved with XEphem development together with XEphem's author Elwood Downey.

I can assure you that a 2d precision ephemeris program like XEphem is just unbeatable for being connected to a GOTO telescope (or with some available extensions to a professional telescope dome). There are many commercial programs for Windows that claim the same functionalities. But if people want /professional/ level accuracy, then there is no alternative to XEphem. By the way, every physics or astronomy institute worldwide has XEphem as a standard installation at least on their UNIX machines.

Many Windows users can neither judge nor do they care for the amount of precision XEphem offers (free of charge).

Bye Fridger

selden wrote:That is strange.

I used search just now, looking for telescope, and got 247 matches.
telescope AND control yielded 10 matches

Maybe you did a typo?

Wouldn't be the first time... :roll:

t00fri wrote:I can assure you that a 2d precision ephemeris program like XEphem is just unbeatable for being connected to a GOTO telescope (or with some available extensions to a professional telescope dome).

I got ya, I totally understand, and it's a good point. I guess I could refrase why I think it would be cool. XEphem, looks totally powerful. But I'm looking at a star in the Pleades via Celestia at the moment. In that moment to have some way to trigger my scope to GOTO it if it's in the sky would also be powerful AND beautiful!

I think it makes total sense to have something like XEphem for power use, and detailed scientific level calculation...

:idea: Perhaps a better way to atack the problem would be to: find a way to send the currently selected object's name (or Catalogue# or M# etc...) to XEphem via a command line or some runtime compiled script, so that the GOTO in the telescope can be effected, in a streamlined fashion. I haven't looked at the feature set in too much detail yet, but perhaps it will have a command line interface so I can do just that!

Also, I know I'll neatly fit myself into into the "dumb windowz user" category after this comment, but: XEphem looks like it needs to be compiled via Cygwin, on the Windows plat. I know that I will do it because I'm always looking to learn something new, or find any availible astronomy software, but it isn't a very "widely accessable" distribution methods to most users... even Celestia has native installer availible! :twisted:

Thanks so much for taking the time to write... I look forward to checking out XEphem, and to dreaming of a connection between it and Celestia :)

Best!
Jonathan Mickelson

jwmickelson wrote:
I got ya, I totally understand, and it's a good point. I guess I could refrase why I think it would be cool. XEphem, looks totally powerful. But I'm looking at a star in the Pleades via Celestia at the moment. In that moment to have some way to trigger my scope to GOTO it if it's in the sky would also be powerful AND beautiful!

Well, being myself an active amateur astronomer since childhood, that "GOTO way" of observing will always remain a mystery to me . I would /manually/ find that particular star in the Pleiades sooooo much quicker than that NOISY motor (in case of a Meade LX200, for example ).

What is much more challenging for GOTO fans is to have the scope move /precisely/ to a 13.5 magnitude galaxy, say, that you could never spot visually. It's going to be very weak also in the scope and requires averted vision to be even noticed! In such much more interesting cases, it is /essential/ that the scope ends up with placing that galaxy "dead centered" in the field. This requires both an excellent mounting and software of excellent precision like XEphem.

We are just now incorporating large sets of galaxies into Celestia. There is no comparable OpenCluster data and no Nebula data implemented yet. The problem is much harder for a 3d program like Celestia than for 2d mapping software, since for each such object we require also /distance/ information besides RA and DEC.

In contrast, XEphem works with all available professional catalogs (after simple Perl script conversion to *.edb format) and has a nice GUI for loading and unloading individual catalogs.

We certainly would not go through all the work to implement a sophisticated RS232 telescope interface just for people watching stars in the Pleiades (!) via "push button" . There is one basic criterion of design in Celestia: if we decide to implement a new feature, we want to do it VERY WELL. ...since that means usually a lot of work, we normally think twice about it's scope of application before starting.


Bye Fridger

PS: Elwood was selling some time ago a /native/ Windows version for little money. He might have given up doing so. The reason why this was not free is because he had to buy a /commercial/ licence for compiling the stuff in Windows.
But indeed, XEphem compiles without the slightest problems under CYGWIN. It looks very nice and is pretty fast, even on my oldish 1 GHz PIII notebook.