This indicates, Ho says, the presence of some kind of a central engine – a just-born black hole accreting matter, or a rapidly rotating, highly magnetised neutron star. The short-wavelength radiation from the Cow that ALMA picked up continued for weeks, again unlike a typical supernova, enabling the team to observe the phenomenon for 80 days. First, she used (remotely) the Submillimeter Array in Hawaii, and then - the Atacama Large Millimeter/Submillimeter Array (ALMA) in Chile. Astronomer Anna Ho at the California Institute of Technology and the lead author of a paper accepted to the Astrophysical Journal, started observing the Cow in radio. It also reached its peak brightness over just a few days, while typical supernovae can take weeks, and the Cow’s visible light disappeared in just 16 days the supernova observed in 185 AD, for example, lasted at least eight months.īut soon data in other wavelengths started trickling in. First, the event was unnaturally bright – 10 to 100 times brighter than the typical blast of an exploding star. Until now, scientists had classified seven different types of Supernovae (Type 1a, 1b, 1c, II, III, IV and V), but the Cow is different. The term supernova was coined by Swiss astronomer Fritz Zwicky in 1934. Supernovae have been observed since 185 AD, when Chinese astronomers recorded their observations of a “guest star”. That’s a theory, though, and the Cow could be the most direct evidence yet of how such an event unfolds. The core collapses into either a black hole or a neutron star. When a massive star dies, its core implodes, causing a bright explosion – a supernova. And it happened in the (relatively) nearby constellation Hercules, on the outskirts of a dwarf galaxy there. The main theory is that we have witnessed a collapse of a star in action – forming a black hole or a neutron star, a sort of super-dense stellar corpse, 200 million years ago. Researchers are still trying to make sense of what exactly the Cow is (or was), though. Apart from the two ATLAS telescopes, the veteran Keck twins, also in Hawaii, swiveled into action, together with a telescope on La Palma, one of Spain’s Canary Islands, and several other instruments - focusing on the event for days, weeks and months.
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