Dear all,
I am doing photometry using PHOTOM and CURSA. PHOTOM works OK but I have
found some strange behaviour when running the CURSA routine
catphotomfit. Basically, if I set the parameter FIXED to FALSE, the
routine should fit two parameters ("zero point" and "atmospheric
extinction"). However, running the routine in this way gives a constant
"zero point" = 0.000000, and what seems to be a random "atmospheric
extinction". In other words, if I run the command repeatedly, I don't
obtain the same value for the second parameter. That should not be the
case, I guess.
A workaround I have found is to set FIXED=TRUE, then setting both FZEROP
and FATMOS to FALSE (which should be equivalent to setting FIXED=FALSE).
Then the routine does a fit which looks reasonable in most cases but I'm
not happy about this because it makes me feel suspicious about the
results I get. Could anybody please have a look into this, please? If
needed I can provide suitable tables of magnitudes and airmasses (in
CURSA format) to use as a test.
Thanks in advance,
--
Eduardo Unda-Sanzana - [log in to unmask]
Research (in English): http://eduardo.almagesto.org/research
Personal (in Spanish): http://eduardo.almagesto.org
"Solamente lo barato se compra con el dinero" (A. Cortez)
