Let me share with you some further star trail photography findings.
First, it’s good to have a location in mind where the sky is as clear as possible. Large cities are not the best choice, as pollution can hinder the visibility of the stars. In addition, checking the weather conditions for the night is essential. If the sky is overcast, then it’s game over before it has even started! The same applies when the moon shines. “No moon” nights are ideal, otherwise it’s better to wait until it sets. So do some pre-work by finding out the “moonset” time and reading the weather forecast.