Please check this cropping at 100% of a night sky.
I took this photo on a Nikon D750 with a Nikkor 50mm f / 1.4 D @ f / 8, ISO 100, RAW format.
I had already noticed this kind of noise / hot pixels (all these little RGB dots) on much longer photos, above 10 to 15 minutes. But this blow was only 269 seconds (less than 5 minutes).
Is this a sign that my sensor is slowly dying? And can I do anything to prevent this from happening outside of activating long exposure noise reduction?