Assertion: telescope's mirror | /r/CapableOf | groundbreake work
Facets:
value: on the spectra of sunspots
type: LOCATION
Source sentences:
text: Its 24-inch (61 cm) primary mirror with a 60-foot (18 m) focal length, coupled with a spectrograph, did groundbreaking work on the spectra of sunspots, doppler shift of the rotating solar disc and daily solar images in several wavelengths.