Re: AstroImageJ won't build Master bias
Posted by
karenacollins on
Jul 14, 2020; 6:06am
URL: http://astroimagej.170.s1.nabble.com/AstroImageJ-won-t-build-Master-bias-tp644p1399.html
The biggest limitation to your current formatting (either jpg or
FITS) is that you do not have DATE-OBS or EXPTIME keywords in the
header. The DATE-OBS keyword let's AIJ know the start time of the
observations and then combined with the EXPTIME keyword can
calculate the center time of the exposure. Without that information,
almost no new header data can be calculated, and when you plot
photometry, AIJ will not know the time for each specific
measurement, so will only be able to plot photometry in numeric
sequence relative to the order each image is processed.
You may be able to add this information by hand (if you know the
start time of each exposure), but it would be tedious work unless
you only have a few exposures to process.
Karen
On 7/13/2020 7:18 AM, elahe lashgari
[via AstroImageJ] wrote:
Dear Karen,
yes, thanks a lot. after updating to daily build, JPG images also
work. but as you said before, with FITS it goes better. if I turn
off FITS header update, I will lose some information in my final
measurements table, right? I plot a light curve of binary stars
without doing plate solve. does it make any problem without plate
solve?
I also need to choose a reference star in multi-plot photometry.
how can I do that? because after I select Target star with that
green aperture, the rest of my selections appeared to be
comparisons and not a reference star.
Thanks,
Ela