[AstroPy] astropy.vo.client conesearch radius problem?

[Francisco Gallardo lópez]

Hi Evert!

Thanks a lot for answering.

I would say it only happens with the USNO catalogs, both 'The PMM USNO-A1.0
Catalogue (Monet 1997) 1' and 'The USNO-A2.0 Catalogue (Monet+ 1998) 1'.

I created a small code to show the thing (please find it attached to this
email).

It iterates through all the available catalogs and breaks into the debugger
as soon as the query returns some sources (with the AR,DEC hard-coded in
the program, only USNO catalogs will return sources). It stores the result
in the “temp” variable. No big deal.

For instance, with the second catalog (*'The USNO-A2.0 Catalogue (Monet+
1998) 1')* and the sky position (ra=159*.31*5075782, dec=-27.6515145412):


<Table masked=True length=49>
    _r       USNO-A2.0    RAJ2000    DEJ2000   ...   Bmag    Rmag   Epoch
   deg                      deg        deg     ...   mag     mag      yr
 float64       str13      float64    float64   ... float32 float32 float64
---------- ------------- ---------- ---------- ... ------- ------- --------
  0.041089 0600-13508332 159.269631 -27.643284 ...    19.3    17.9 1981.701
  0.039111 0600-13508442 159.271653 -27.644431 ...    20.2    17.9 1981.701
  0.038170 0600-13508467 159.272078 -27.654039 ...    20.6    17.5 1981.701
  0.039771 0600-13508743 159.277409 -27.629875 ...    19.8    17.9 1981.701
  0.031614 0600-13508894 159.280334 -27.644278 ...    19.8    17.9 1981.701
  0.037095 0600-13509081 159.283342 -27.675723 ...    16.1    15.6 1981.701
       ...           ...        ...        ... ...     ...     ...      ...
  0.040114 0600-13512624 159.348720 -27.678370 ...    15.9    15.4 1981.701

=========================================================


I would say it is not paying attention to the requested radius. (Again,
this does not happen with other catalogs, only with the USNO catalogs)

Thanks a lot!
BR
Fran

2017-01-16 8:46 GMT+01:00 Evert Rol <evert.rol at gmail.com>:

>  Hi Francisco,
>
> Could you send a short working code example around that shows the actual
> problem?
> Possibly for both the GSC (ok) and the USNO catalogs (not ok).
>
> Evert
>
>
>
> > Hi all!
> >
> > I looked in the Internet but I did not find references to this problem,
> so maybe I'm making something wrong.
> >
> > So I'm using the conesearch from astropy.vo.client to query some
> catalogs (indeed all the catalogs that are returned by
> conesearch.list_catalogs() ).
> >
> > The thing is, I'm using a radius of 0.2 seconds of arc and it seems like
> when querying some catalogs the results seem to be out of that requested
> radius. For instance, two sources returned by the query were, one at
> ra=5.602814 deg and another one @ ra=5.536589 deg.
> >
> > That does not happen with the 'Guide Star Catalog v2 1' which seems to
> work properly, it happens when requesting the The PMM USNO-A1.0 Catalogue
> (Monet 1997) 1'.
> >
> > Am I missing something or making something wrong or is it a known bug?
> >
> > Thanks a lot!
> > BR
> > Fran Gallardo
> > _______________________________________________
> > AstroPy mailing list
> > AstroPy at scipy.org
> > https://mail.scipy.org/mailman/listinfo/astropy
>
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