Redirect to:Messier 77This page is a redirect. The following categories are used to track and monitor this redirect: From a systematic name: This is a redirect from a systematic name to a more commonly used name. For example: In chemistry: 2-methyl-1,3-butadiene2-methyl-1,3-butadieneIsoprene In astronomy: 1P/Halley1P/HalleyHalley's Comet When appropriate, protection levels are automatically sensed, described and categorized.