Dear IRAF people,

I am trying to use DAOPHOT with my CCD observations.

But I get the error below when I run daofind. Do you have any idea what this error related with?

There was an old topic in the Forum I found also concerns the same error. But solution isnt specified.

http://iraf.net/phpBB2/viewtopic.php?t=81740&highlight=daofind

Also when I do rfits to those images it gives the same error. I dont know what is wrong with files. I can supply an example image or header if you'd like to see.

*****************************************************************
--> daofind
Input image(s) ('v0000050ri.fit'):

FWHM of features in scale units (3.) (CR or value):
New FWHM of features: 3. scale units 3. pixels
Standard deviation of background in counts (INDEF) (CR or value): 10
New standard deviation of background: 10. counts
Detection threshold in sigma (3.) (CR or value):
New detection threshold: 3. sigma 30. counts
Minimum good data value (INDEF) (CR or value):
New minimum good data value: INDEF counts
Maximum good data value (INDEF) (CR or value):
New maximum good data value: INDEF counts

Killing IRAF task `daofind'
Traceback (innermost last):
File "<CL script CL1>", line 1, in ?
iraf.daofind(_save=1)
IrafError: Error running IRAF task daofind
IRAF task terminated abnormally
ERROR (828, "Cannot open pixel file (den6856a)")

**************************************************************************

By the way I am using principally PyRAF but I also tried this and got the same error with ordinary CL.

Thanks a lot..

Best wishes,

Sinan Alis
Istanbul University
Astronomy and Space Sciences Dept.

A 'cannot open pixel file' typically means the 'imdir' variable is improperly defined (e.g. points to a directory that doesn't exist, bad syntax when using HDR$, etc). The imdir defines where the .pix half of an OIF image-format goes and is defined in the login.cl file or can be reset on the commandline using

cl> reset imdir = "/path/imdir/"       # <-- note trailing '/'
cl> reset imdir = "HDR$"       # put .pix in same dir as .imh
cl> reset imdir = "HDR$pix/"     # put .pix in a 'pix' subdir of .imh
cl> flpr 0           # zero, not 'oh'

The flpr is needed to reinitialize tasks in the cache.

Likewise, on input the message means the imdir specified in the .imh head doesn't contain a valid path to the .pix file. This can be fixed by editing the i_pixfile header field with the correct path (see the FAQ). Lastly, if you can't even IMHEAD the image then it may be a byte-swap issue e.g. as when trying to read an old image from a tar backup. In this case, the pixfile path is also commonly wrong and needs editing.

Cheers,
-Mike