On Fri, 11 Aug 2006, Mark Taylor wrote:
> Peter when you're back, or anybody else who knows,
>
> I've got a funny with GAIA. There is an image file and a catalogue file
> at
>
> ftp://andromeda.star.bris.ac.uk/pub/star/data/gaia/iras_psc.fits
> messier.TAB
>
> These are basically full-sky data sets. If I load the FITS file and
> then the catalogue (Data-Servers|Local Catalogs|Load from file...),
> not all the points from the catalogue show up, only those within
> a certain RA range (e.g. M1 and M2 are missing, the first one visible
> is M3). If I subsequently Select Area... over a missing part of the
> data (e.g. top left) followed by Search, the missing objects in
> the selected region show up.
>
> I suspect this could be a bug related to the fact that the field of
> view is very large (whole sky). However it may be some kind of a
> feature that I don't understand.
Hi Mark,
as you suspected this is down to the size (on the sky) of the image. I
just run astDistance to get some "radius" of the image in radians, but
clearly at this scale there's a shorter way around the great circle
between the two points I've chosen (bottom left and centre of image).
David, is there a better way to size an image in world coordinates?
Cheers,
Peter.
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