Assertion: comet's brightness | /r/HasProperty | peak
Facets:
Source sentences:
text: Passing 0.42 au from Earth on 30 November 1680, it sped around an extremely close perihelion of 0.0062 au (930,000 km; 580,000 mi) on 18 December 1680, reaching its peak brightness on 29 December as it swung outward.
text: On 20 April 2013, Lemmon crossed the celestial equator and became primarily viewable in the Northern Hemisphere, though by this time the comet was significantly dimmer relative to its peak brightness.
text: Passing 0.42 au from Earth on 30 November 1680, it sped around an extremely close perihelion of 0.0062 au (930,000 km; 580,000 mi) on 18 December 1680, reaching its peak brightness on 29 December as it swung outward.