A live comparative star photometry feature?
Posted: Sat Apr 03, 2021 12:01 pm
Hi Robin,
just thought that a feature like this would be an addition of interest to quite a few folk - especially say for graphically monitoring short period variable stars in real time? It could add livestack type 'immediacy' and accessibility to what is otherwise an area of astronomy that requires patience and post-analysis to 'see'. --- which is probably why I have never explored it
I imagine that it would require at least the ability to select say a 50 pixel circle around each of at least two target stars as well as to designate a control 'dark background' spot within a given frame (or perhaps better within a short substack of frames aligned within livestack). It would then require the ability to measure the integrated signal and standard deviations within the 3 or more areas, do the subtractions and output the signals or signal to noise of the stars to a graph --all within the time that the next frame (or autostack of subframes) was being collected.
Apart from variable stars such a tool might also be useful for monitoring SNR variation at different times for selected objects or parts of objects?
I am guessing that your livestack Frame brightness selection tool monitors the transparency aspect of SNR in a general way across a whole frame by monitoring star count - it too could be a useful number to output?
Possibly too futuristic but I was reflecting that SC already seems to have quite a few of the required capabilities ...although in different parts of the program i.e.
1) successive frames constantly kept accurately aligned live during stacking
2) autostack feature creates substacks that are also aligned with later substacks
3) reticule pointer tool in SC 4.0 that allows you to select a spot within a frame (currently for recentering the image and mount control)
anyway another one for your consideration
best wishes
TimH
just thought that a feature like this would be an addition of interest to quite a few folk - especially say for graphically monitoring short period variable stars in real time? It could add livestack type 'immediacy' and accessibility to what is otherwise an area of astronomy that requires patience and post-analysis to 'see'. --- which is probably why I have never explored it
I imagine that it would require at least the ability to select say a 50 pixel circle around each of at least two target stars as well as to designate a control 'dark background' spot within a given frame (or perhaps better within a short substack of frames aligned within livestack). It would then require the ability to measure the integrated signal and standard deviations within the 3 or more areas, do the subtractions and output the signals or signal to noise of the stars to a graph --all within the time that the next frame (or autostack of subframes) was being collected.
Apart from variable stars such a tool might also be useful for monitoring SNR variation at different times for selected objects or parts of objects?
I am guessing that your livestack Frame brightness selection tool monitors the transparency aspect of SNR in a general way across a whole frame by monitoring star count - it too could be a useful number to output?
Possibly too futuristic but I was reflecting that SC already seems to have quite a few of the required capabilities ...although in different parts of the program i.e.
1) successive frames constantly kept accurately aligned live during stacking
2) autostack feature creates substacks that are also aligned with later substacks
3) reticule pointer tool in SC 4.0 that allows you to select a spot within a frame (currently for recentering the image and mount control)
anyway another one for your consideration
best wishes
TimH