Astronomy photo are much different from normal photo you got with the camera, and olso the cameras are different, you can use normal reflex but are not suitable at all (normal camera got infrared filter cut, and in the infrared you got nebulose dust signal).
A "simple" night of an astrophotographer:
You took a lot's of frame in the same object (we are talking about 1,5,10 minutes of exposure for each photo), we will call it "lights".
One time for year (if your camera got thermal control) you will do the "dark library" you set the camera temperature you use major times (-20°c for winter, 0° or -10° for summer, (professional camera got peltier cell to avoid reading noise) if your camera don't have thermal control you need to do it after light, these dark frame should be done with the same shutter speed and temperature you used to get lights, in this way you get all the noise that camera generate, in poor word you cover the scope and you continue to make lights frame (but they will be dark)
Some cameras need olso bias frame, a dark frame made at the much fast shutter speed your camera can do, and at the same temperature your lights was made.
After you collect all the lights and darks, you make "flat frames" you have to point the scope to a flat panle that is no more than a brigth square, you can use olso the sun light at the sunset or sunrise, in theory the ligth that goeas inside the telescope should be linear in all the points.
Flat frames are used to remove dust spots and vignetting from all your ligths frame.
Of course if you have a stickers on your lens or mirror this will not help you.
Flats frame have just one requirement, the histogram should be at the 50%, you can use the shutter time, gain or iso you want, and this is why I need to drim my flat panel cause the software I use can adjust the brightness by himself.
At this point some related software calibrate aech light frame removing the signal readed from bias and dark frames, and will adjust the linearity of the signal using the flat frames.
After that you get have calibrated light frames, and with some algorithms the lights frame are been stacked togheter, and you get one single frame that contain all the usefull signal you get with all the single light frames that you need to elaborate to get the resoult you want.
This is in very poor word omitting some tecnical object and parts how astrophotograpy work
and I need the PWM to drimm the brightness of the flat panel, my PWM finish to a mofset that "drim" the led strip.
probably is the best solution to avoid flickering