Astroquery VizieR UCAC4 full download
<p>I would like to have a local (offline) ASCII version of <strong>UCAC4</strong> star catalogue in order to have an isolated work environment (no internet).</p>

<p>I am having issues trying to retrieve this specific <em>full</em> catalog. Downloading small parts is pretty straightforward using <strong>topcat</strong> <em>VO->Vizier service</em> option or even the CdS web interface, but I did not manage full catalogue retrieval .</p>

<p>My best shot was using Python scripting Astroquery (<a href="http://astroquery.readthedocs.io/en/latest/vizier/vizier.html" rel="nofollow">http://astroquery.readthedocs.io/en/latest/vizier/vizier.html</a>) but the following function call for instance does not return nearly enough stars when it should download half the catalogue (Northern part of celestial sphere):</p>

<p><code>ucac4 = v.query_region(coord.SkyCoord(ra=0, dec=45, unit=(u.deg, u.deg), frame='icrs'), width=90, height=360, catalog= 'I/322A')</code></p>

<p><code>width</code>/<code>height</code> seem to refer to <em>declination</em>/<em>ra</em> in this order. (I am wrong with the usage of the box ?
)</p>

<p>I also tried to iterate on smaller parts of the sky and it improves the density, but I still seem to have missing objects and cannot figure out why.For instance, I tried to iterate on 0.2Â° declination steps so I could cross check with this file :
<a href="ftp://cdsarc.u-strasbg.fr/pub/cats/I/322A/UCAC4/u4i/zone_stats" rel="nofollow">ftp://cdsarc.u-strasbg.fr/pub/cats/I/322A/UCAC4/u4i/zone_stats</a>
but the <code>query_region</code> function does not return the expected amount of stars...</p>

<p>And I also tried Astrosurf links but I cannot just use these files because I want it in an ASCII format.</p>

<p>Fastest solution : get the <a href="http://vizier.u-strasbg.fr/vizier/doc/cdsclient.html" rel="nofollow">cdsclient</a> package. Run the finducac4 program with -whole option, for example :
finducac4 -whole -m 115000000 > myUcac4.dat</p>

python astronomy astropy