What is an astrolabe? it was used to plot latitude using the sun. it was used to locate the earth's position. it was a tool meant to plot longitude and was invented by muslims. it was a navigational instrument rejected by europeans as a pagan device?

The answer is:

It was used to plot latitude using the sun.

The astrolabe was a device used by the seafarers or the captain at sea in order to calculate the latitude of the ship, by measuring the angle between the horizon and the sun. In the past, this was mostly used by the astronomers and navigators to measure the inclined position in the sky of a celestial body, day or night.

It was an Ancient Greek invention, lost to Europeans during the Middle Ages. It could find latitude if you knew the exact time and date, or conversely find the time and date if you knew your location. Could also tell what time the sun set, rose, and when twilight was.