auroscope
/ˈɔrəˌskoʊp/
noun
- A device used to observe the aurora borealis or aurora australis.
- The museum had an old auroscope on display from the early 20th century.
- Using an auroscope, they could see details in the aurora that were invisible to the naked eye.
- The astronomer set up an auroscope to study the northern lights.