Is it pitch black during astronomical twilight?
Quick Answer: No, it is not pitch black during astronomical twilight. The sky is very dark but still has a faint glow, as the Sun is between 12 and 18 degrees below the horizon, allowing some indirect sunlight to scatter in the atmosphere.
Astronomical twilight happens after sunset or before sunrise when the Sun is just below the horizon but not far enough for complete darkness. This means stars become visible, but the sky is not fully black.
The faint light still present comes from the Sun’s rays scattering in the upper atmosphere. So, you get a very dark sky, great for stargazing, but not absolute pitch blackness.