Specialist astrophotography cameras are geared toward photographing the night sky. Long exposures keep circuitry running for long periods and electronic components can heat up during this time, which results in thermal-induced image noise. Since astro cameras have a predisposition to heat up during long exposure shots many models have built-in cooling fans and specific design features to keep the performance of the image capture high; it will likely be larger and heavier and a little noisier as the fans whir while operating.