The top 2 were taken using a modified DSLR mounted to a scope, the mount tracks the night sky & with some software another smaller scope & camera locks onto a star & tracks it so you can take longer exposures. After taking 30 or so all the images are stacked so you get the most from the data then processed to bring out the best of what you have. Sounds complicated & it is lol, I'm still learning although I haven't done a lot lately.
The image of the Sun was taken using a Lunt 35 Hydrogen Alpha solar telescope with a mono video camera. After about 30 seconds worth its ran through software to get the best frames & stacked, then the rest is processed to sharpen up the image & add some colour.
Unfortunately most deep sky imaging isn't a one shot deal as you have to get the best from the data you have although things like Moon shots you can still get pretty decent single shots although it's probably an idea to take a few due to atmospheric distortion & pick the best one.
Phew!!
You can get a bit of kit called the Skywatcher adventurer, it sits on top of a tripod & tracks the sky while your camera takes pictures. Good for Milky Way pictures or widefield shots as you can take longer exposures as it's tracking.
I really must have a go some time at trying to take photos of the night sky. The only one I remember taking (and can still find) is this ........
I took it 5 or 6 years back, hand held (leaning against the shed), with a Pentax K200D DSLR and a 50 year old (Yes 50!!) Taisei Kogaku [Tamron] Model 490 400mm f/7.5 T-mount lens that I bought for £20 on Fleabay. It is one of the very first Tamron T-mount lenses, manufactured around 1963.