Display of UCAC in Guide

Guide can now display and give information from the UCAC1, treating it as a "user-added dataset". It will show the stars on-screen; you can click on them and get "more info" about them. Here's an example of the information given:

UCAC (USNO CCD Astrograph Catalog) star
Magnitude 14.01
RA: 19h03m08.89s (J2000)
declination: -21 48' 00.8"
"Raw" RA from the file: 1 028 833 401 +/- 17 milliarcseconds
"Raw" SPD from the file: 245 519 180 +/- 15 milliarcseconds
6 observations made
Mean epoch: 1999.585
   (The above is the mean epoch of the UCAC observation,  _not_
   the mean epoch based on all catalogs!)
Proper motion in RA: -2.9 +/- 10.8 milliarcseconds/year
Proper motion in dec: -10.3 +/- 10.8 milliarcseconds/year
2 catalog positions were used in determining the proper motion

To do this, you'll need to download the .TDF file for this dataset (about 4 KBytes, unZIPping to about 72 KBytes).

Do this, run Guide, and you can go into "Extras... User-Added Datasets", select "UCAC1", and determine the manner in which data from that catalog is displayed. You can then right-click on UCAC stars and get "more info" about them.

Guide assumes that one or more of the UCAC "zone" files, z001 through z169, are in the directory in which Guide is running. If you've put the files elsewhere, you'll have to edit UCAC.TDF and change all lines of the form

file z### 

to reflect the actual path to the data (there are, logically enough, 360 such lines, z001 through z360, one for each possible half-degree zone... I realize only z001 through z169 exist right now, but that will be remedied eventually.)

Click here for information on use of UCAC1 with Charon.

If you just want to use UCAC1, the above is all you need to know. People making new .TDF files may want to exploit the "new features" I mentioned, and should keep reading.

Almost all of said new features involve ways to handle datasets that span many files. Previously, the only way to do that was to treat each file as a separate dataset, leading to 169 datasets now and 360 when UCAC is completed. Now, though, if Guide sees consecutive datasets in a .TDF file with the same "titles", it'll list them and control them as if they were a single dataset.

I also wanted to avoid having to repeat the 'comments and remarks' sections (the lines beginning with ~r, ~c, or ~b). The new "go_to_top" statement tells Guide that the comments for a given file are those for the first file in the .TDF. (I couldn't find a simple way to say that. But if you look at UCAC.TDF, the meaning should be apparent.)

Finally, I had to revise the .TDF system to handle units of south polar distance (SPD) instead of declination, with the angles expressed in milliarcseconds. Thus, the "units0 -3" and "units3 -3" lines.