中文翻译与英英解释

n.
【天文学】量日仪。

an instrument used to measure the angular separation of two stars that are too far apart to be included in the field of view of an ordinary telescope

Heliometer (from Greek sun and measure) is an instrument originally designed for measuring the variation of the sun's diameter at different seasons of the year, but applied now to the modern form of the instrument which is capable of much wider use.