Author Topic: Saving in FIT format compatible with VPHOT for variable stars?  (Read 119 times)

Offline magnusl

  • PixInsight Enthusiast
  • **
  • Posts: 84
    • View Profile

I've recently begun to try to do photometric measurements of variable stars. My standard calibration procedure is in PixInsight, but then for various reasons, I want to import my calibrated images to AAVOS's online program VPHOT to do the photometry. However, I run into problems here. VPHOT cannot read xisf, which is the format my calibrated images are saved in. So I re-saved them in FIT format.
But I'm having problems. Either they are just white when loaded in VPHOT, not showing any stars to measure, or VPHOT cannot measure because it thinks the stars are too faint. There seems to be something wrong with the FITS format I choose. I've tried 32-bits floating point, and 16-point integeger, but I'm at a loss here.

So: anyone knows how to save calibrated images in PI in a fits format that is compatible with VPHOT - not just for displaying image but for photometric measurement? More generally - how would I need to change my calibration procedure to make this work with VPHOT?

Or should I not calibrate in PI at all, for this purpose?