Issue with centroiding

Posted by ghawkins on Feb 24, 2022; 1:34am
URL: http://astroimagej.170.s1.nabble.com/Issue-with-centroiding-tp1786.html

I'm not sure if this is an issue, or the fact I don't understand what is happening.

I'm trying to analyze the standard starfield M67. I've download the AAVSO photometric table and separated out the RA/DEC for the 178 comparison stars.

I import this RA/DEC list for an M67 image and I see apertures appear in PINK over the stars.  In most cases they are slightly off center.  With centroiding set, when I click place apertures, the majority of the apertures reposition correctly over the appropriate star, turning RED in the process.  However, for a small number of stars the centroiding does not work so well, even occasionally selecting a brighter nearby star, or the center point between two closely located stars.

What can I do to stop/control this?

Best regards,

Gary