PCC can't find any stars

gnewell

Well-known member
Aug 19, 2018
59
2
Using the same process steps, same FOV/scale, I've used successfully before, first solving image then using PCC, today I get:

Downloading Vizier data:​
http://cdsarc.u-strasbg.fr/viz-bin/asu-tsv?-source=II/336/apass9&-c=188.992575 27.959311&-c.r=0.491452&-c.u=deg&-out.form=|&-out.add=_RAJ,_DEJ&-out=B-V&-out=Vmag&-out=Bmag&-out=g'mag&-out=r'mag&-out=i'mag&Vmag=0..16​
1808 bytes transferred in 0.47 s @ 3.76 KiB/s​
Removed 0 duplicate objects​
FOV:0.491 actual:0.000​
Catalog APASS size: 0 objects inside the image​
*** Error: Failure to process image file 'C:/Users/Glenn.THEBEAST/AppData/Local/Temp/PCC_R_IDLTU97E53KF.xisf': Could not find any stars in the catalog​

Followed by other errors because of this.

I've tried forcing the solve again, which succeeds but gives the same error, and messing with the magnitudes, to no avail. Note that according to Stellarium my image contains mag 11 stars, and the auto setting is looking for 0..16 so it should work.

The "FOV:0.491 actual:0.000" looks suspicious.

Here is what is coming back from Vizer:

"​
#​
# VizieR Astronomical Server cdsarc.u-strasbg.fr​
# Date: 2020-06-04T19:31:34 [V1.99+ (14-Oct-2013)]​
# In case of problem, please report to: cds-question@unistra.fr
#​
#​
#Coosys J2000: eq_FK5 J2000​
#INFO votable-version=1.99+ (14-Oct-2013)​
#INFO -ref=VOTx18999​
#INFO MaxTuples=50000​
#INFO queryParameters=13​
#-oc.form=D.​
#-source=II/336/apass9​
#-c=188.992575 27.959311​
#-c.r=0.491452​
#-c.u=deg​
#-out.add=_RAJ,_DEJ​
#-out=B-V​
#-out=Vmag​
#-out=Bmag​
#-out=g'mag​
#-out=r'mag​
#-out=i'mag​
#Vmag=0..16​
#​
#INFO -c=188.992575+27.959311,rd=0.491452​
#Constraint Vmag=0..16​
#RESOURCE=yCat_2336​
#Name: II/336​
#Title: AAVSO Photometric All Sky Survey (APASS) DR9 (Henden+, 2016)​
#Table II_336_apass9:​
#Name: II/336/apass9​
#Title: The APASS catalog​
#Column _RAJ2000 (F12.8) Right ascension (FK5, Equinox=J2000.0) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services) [ucd=pos.eq.ra]​
#Column _DEJ2000 (F12.8) Declination (FK5, Equinox=J2000.0) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services) [ucd=pos.eq.dec]​
#Column B-V (F6.3) [-7.5/13]? B-V color index [ucd=phot.color;em.opt.B;em.opt.V]​
#Column Vmag (F6.3) [5.5/27.4]? Johnson V-band magnitude [ucd=phot.mag;em.opt.V]​
#Column Bmag (F6.3) [5.4/27.3]? Johnson B-band magnitude [ucd=phot.mag;em.opt.B]​
#Column g'mag (F6.3) [5.9/24.2]? g'-band AB magnitude, Sloan filter [ucd=phot.mag;em.opt.B]​
#Column r'mag (F6.3) [5.1/23.9]? r'-band AB magnitude, Sloan filter [ucd=phot.mag;em.opt.R]​
#Column i'mag (F6.3) [4.2/29.1]? i'-band AB magnitude, Sloan filter [ucd=phot.mag;em.opt.I]​
"​

Thoughts?
 

pfile

PTeam Member
Nov 23, 2009
5,221
57
if i launch that query with an FOV of 0.75 there are about 15 stars returned. maybe the FOV is just too small for that survey?

rob
 

gnewell

Well-known member
Aug 19, 2018
59
2
OK, but I don't see how to change either the fov, or the survey in the PCC dialog.

The only survey I have in the dropdown is APASS, and I don't see any box for changing the fov.

Also as I said this has been working for me up to today, with the same FOV and image scale, for instance the M13 I posted on astrobin yesterday.
 

pfile

PTeam Member
Nov 23, 2009
5,221
57
hmm. well the FOV is i'm sure calculated automagically from the image scale and the pixel dimensions of the file. could it be a bug? does the computed FOV seem right? it would be a hack but if you increased the size of the image by adding borders with crop, perhaps PCC would request a larger FOV when making the query. regardless if there are no stars in the catalog in the actual FOV PCC would probably still fail.

i know that in the past there have been issues with various catalogs where they don't cover certain portions of the sky that well. at least whatever PI is doing is consistent with a manual query with the same FOV and RA/Dec.

rob