[daip] IMFIT output

[Hans-Rainer Kloeckner]

Dear Eric,

	sorry for bothering you and I hope it will not eat up to much time to  
answer my question.

Im running into a problem in the RA and DEC output of the task IMFIT

IMFIT1:   X-position        =   1525.617 +/-   0.0034 pixels
IMFIT1:   Y-position        =    990.460 +/-   0.0036 pixels
IMFIT1:                       RA 01 41 36.60758    +/-  0.0001825
IMFIT1:                       DEC 21 08 53.5011    +/-   0.002681

Reading the values for the pixel offset of the MF table with  
ParselTongue gives me

X = 1525.61657715
Y = 990.460449219

and the Header information for RA and DEC of the image is

decinfo = [21.155416659760721, 1025.0, 0.00020802661310881376, 2048]
rainfo  = [25.514416666666662, 1024.0, -0.00020802661310881376, 2048]

and calculating with

decindeg = decinfo[0] + ( y - decinfo[1] ) * decinfo[2]
raindeg  = rainfo[0]  + ( x - rainfo[1] ) * rainfo[2]  /  
cos(decindeg*(2*pi/360.))

the resulting RA is consistent with the RA output, BUT the Declination  
is ~130 mas off !!!

RA    =  1, 41, 36.607591113516094
DEC = 21, 8, 53.633450376233043)

Do I miss something here?


All the best from England

Hans

---------------------------------------------------
Hans-Rainer Kloeckner
University of Oxford
Denys Wilkinson Building
Keble Road
Oxford OX1 3RH
United Kingdom
----------------------------------
surface : room 705
phone   : +44 (0)1865 2-73435 [office]
fax         : +44 (0)1865 2-73594
email    : hrk at astro.ox.ac.uk
---------------------------------------------------