spectrohelioscope

noun

spec·​tro·​he·​lio·​scope ˌspek-trō-ˈhē-lē-ə-ˌskōp 

1

: spectroheliograph

2

: an instrument similar to a spectroheliograph used for visual as distinguished from photographic observations

Word History

Etymology

International Scientific Vocabulary

First Known Use

1906, in the meaning defined at sense 1