I have been using the Goto Coord/Catalog function (which works very well) but am noticing that some objects in the built-in NGC catalog have location errors. When I go to the Soul Nebula, the mount syncs and recenters the object and it is off about half a degree or so. When I do a plate solve it reports this:
RA 02:53:04
Dec +60:30:07
I then use the center pixel function to put the object in the center of my FOV and another plate solve reports:
RA 02:57:42
Dec +60:29:06
Which should be the coordinates in the catalog, but it isn't.
The Heart Nebula is off about 1.5 degrees.
How do I modify the built in catalog to make the corrections?
Mike
Built in NGC Catalog Errors
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Re: Built in NGC Catalog Errors
Hi Mike,
I just checked the catalog file for those targets - in the SharpCap catalog, we have
IC1805 (Heart) RA=02:32:41, Dec=+61:27:24
IC1848 (Soul) RA=02:51:10, Dec=+60:24:08
Both are J2000 co-ordinates, and should be automatically converted to JNOW when used with a mount.
Checking against Stellarium, the Heart is less than 0.5 arc minutes different and the sould is about 1 arc minute different, Considering that both are extended structures, this is a good agreement.
So, I think the co-ordinates stored in SharpCap are correct, or at least well within the boundaries of the nebulae in question, so I don't think there is a problem there.
I can't quite work out what else might be going on here - 1.5 degrees is a big offset...
Unfortunately the NGC/IC catalog is not on disk as a file on its own in SharpCap (it's stored inside another file, so can't be edited). You can go to the full catalog window and find the target you are interested in to confirm that the listed co-ordinates match the catalog co-ordinates shown for that target elsewhere though.
cheers,
Robin
I just checked the catalog file for those targets - in the SharpCap catalog, we have
IC1805 (Heart) RA=02:32:41, Dec=+61:27:24
IC1848 (Soul) RA=02:51:10, Dec=+60:24:08
Both are J2000 co-ordinates, and should be automatically converted to JNOW when used with a mount.
Checking against Stellarium, the Heart is less than 0.5 arc minutes different and the sould is about 1 arc minute different, Considering that both are extended structures, this is a good agreement.
So, I think the co-ordinates stored in SharpCap are correct, or at least well within the boundaries of the nebulae in question, so I don't think there is a problem there.
I can't quite work out what else might be going on here - 1.5 degrees is a big offset...
Unfortunately the NGC/IC catalog is not on disk as a file on its own in SharpCap (it's stored inside another file, so can't be edited). You can go to the full catalog window and find the target you are interested in to confirm that the listed co-ordinates match the catalog co-ordinates shown for that target elsewhere though.
cheers,
Robin