Nemesis is a hypothetical red dwarf or brown dwarf, originally hypothesized in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years),[1] somewhat beyond the Oort cloud, to explain a perceived cycle of mass extinctions in the geological record, which seem to occur more often at intervals of 26 million years and it is said to be dark red in color. In a 2017 paper, Sarah Sadavoy and Steven Stahler argued that the Sun was probably part of a binary system at the time of its formation, leading them to suggest "there probably was a Nemesis, a long time ago".[2] Such a star would have separated from this binary system over four billion years ago, meaning it could not be responsible for the more recent perceived cycle of mass extinctions. It was later disproven, because if it existed, it would have been found by probes mapping the night sky.[3]
In 2011, researchers that analyzed the craters on Earth's surface, which resulted in them concluding that those periodic variations caused by Nemesis that several studies claimed to have found are more likely to be of statistical artifacts.[4]
Gallery[]
References[]
- ↑ EscholarShip
- ↑ UC Berkeley News | There has also been other hypothesis' that suggests the Sun either had one or two stellar companions.
- ↑ Astrobiology (Archived)
- ↑ MPG