Which observation method allows scientists to determine the precise size of a distant Trans-Neptunian Object?

Answer

Monitoring a stellar occultation.

Stellar occultation involves observing an object as it passes directly in front of a distant star. By timing exactly how long the object blocks the light from that star, astronomers can calculate its physical dimensions with much higher precision than they can by relying on brightness estimations and assumed albedo.

Which observation method allows scientists to determine the precise size of a distant Trans-Neptunian Object?
SpaceastronomylargestObjecttrans-Neptunian object