Hi,
Pretty new here.
I've start doing photometry to give a second pourpouse to my little astrophotography setup (DSLR-Small apo-eq mount).
Currently i've run some tests with ASTAP to understend the basic operations, but i have some doubts:
- when ASTAP perform the photometry of the extracted TG channel, in the AAVSO report says "Ensemble of Gaia eDR3 stars, photometry transformed to Johnson-V" so the photometry of TG channel is ready and trasformed according to Johnson V filter.
The same thing is done with the extracted TB channel, so i don't understand if the photometry is reliable or it have to be transformed to Johnson B instead.
Just in case there's a way to do it in ASTAP or there's a tutorial for spreadsheet?
- For a single AAVSO report it's more useful to upload a little group of measurement (ex. 5 * 30" exposure) or a single measurement performed on the average stack of the exposures?
Thanx!
Tue, 09/20/2022 - 11:28
I can only address your last question:
Stack several images. In MOST cases several single exposures taken seconds or a few minutes apart are not needed. While stacking reduces noise, increasing SNR.
Peter
A single measurement performed on the averaged stack of 7 * 30" makes a good datapoint. Depends on the S/N of each image. 7 is a nice improvement over 5 images. Then submit the photometry from the stacked image. If the magnitudes are dim enough to produce low S/N, then average 10 or 20 images.
Ray