Nemesis (hypothetical star)
Nemesis is a hypothetical red dwarf [1] or brown dwarf , [2] originally postulated in 1984 [3] to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years ), [2] 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. [2] [4] As of 2012 [update] , more than 1800 brown dwarfs have been identified. [5] There are actually fewer brown dwarfs in our cosmic neighborhood than previously thought. Rather than one star for every brown dwarf, there may be as many as six stars for every brown dwarf. [6] The majority of solar -type stars are single. [7] The previous idea stated half or perhaps most stellar systems were binary, trinary, or multiple-star systems associated with clusters of stars, rather than the single-star systems that tend to be seen most often. [ citation needed ] In a 2017 paper, Sarah Sadavoy and Steven Stahler argued that the Sun was likely part of a binary system at the time of its formation, leading them to suggest "there probably was a Nemesis, a long time ago.” [8] [9] 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, Douglas Vakoch told Business Insider , adding that "If the sun really was part of a binary star system in its early days, its early twin deserves a benign name like Companion, rather than the threatening Nemesis." [10]
Page Revisions
| Year | Metadata | Sections | Top Words | First Paragraph |
| 2018 |
101047 characters 8 sections 14 paragraphs 3 images 264 internal links 59 external links |
1. Claimed periodicity of mass extinctions 2. Development of the Nemesis hypotheses |
nemesis 0.631 brown 0.222 extinction 0.208 muller 0.192 raup 0.171 sepkoski 0.171 periodicity 0.169 sedna 0.169 dwarf 0.152 star 0.152 wise 0.118 stars 0.109 bambach 0.102 melott 0.102 dwarfs 0.081 |
Nemesis is a hypothetical red dwarf [1] or brown dwarf , [2] originally postulated in 1984 [3] to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years ), [2] 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. [2] [4] As of 2012 [update] , more than 1800 brown dwarfs have been identified. [5] There are actually fewer brown dwarfs in our cosmic neighborhood than previously thought. Rather than one star for every brown dwarf, there may be as many as six stars for every brown dwarf. [6] The majority of solar -type stars are single. [7] The previous idea stated half or perhaps most stellar systems were binary, trinary, or multiple-star systems associated with clusters of stars, rather than the single-star systems that tend to be seen most often. [ citation needed ] In a 2017 paper, Sarah Sadavoy and Steven Stahler argued that the Sun was likely part of a binary system at the time of its formation, leading them to suggest "there probably was a Nemesis, a long time ago.” [8] [9] 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, Douglas Vakoch told Business Insider , adding that "If the sun really was part of a binary star system in its early days, its early twin deserves a benign name like Companion, rather than the threatening Nemesis." [10] |
| 2017 |
95243 characters 8 sections 14 paragraphs 3 images 263 internal links 53 external links |
1. Claimed periodicity of mass extinctions 2. Development of the Nemesis hypotheses |
nemesis 0.588 brown 0.238 extinction 0.222 muller 0.206 raup 0.183 sepkoski 0.183 periodicity 0.181 sedna 0.181 dwarf 0.163 star 0.141 wise 0.127 stars 0.117 bambach 0.110 melott 0.110 dwarfs 0.087 |
Template:Distinguish2 Nemesis is a hypothetical red dwarf [1] or brown dwarf , [2] originally postulated in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years ), [2] 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. [2] [3] As of 2012 [update] , over 1800 brown dwarfs have been identified. [4] There are actually fewer brown dwarfs in our cosmic neighborhood than previously thought. Rather than one star for every brown dwarf, there may be as many as six stars for every brown dwarf. [5] The majority of solar -type stars are single. [6] The previous idea stated half or perhaps most stellar systems were binary, trinary, or multiple-star systems associated with clusters of stars, rather than the single-star systems that tend to be seen most often. [ citation needed ] |
| 2016 |
92289 characters 8 sections 14 paragraphs 3 images 258 internal links 48 external links |
1. Claimed periodicity of mass extinctions 2. Development of the Nemesis hypotheses |
nemesis 0.592 brown 0.240 extinction 0.224 muller 0.207 raup 0.184 sepkoski 0.184 periodicity 0.182 sedna 0.182 dwarf 0.164 wise 0.127 star 0.120 bambach 0.110 melott 0.110 stars 0.105 dwarfs 0.087 |
Template:Distinguish2 Nemesis is a hypothetical red dwarf [1] or brown dwarf , [2] originally postulated in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years ), [2] 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. [2] [3] As of 2012 [update] , over 1800 brown dwarfs have been identified. [4] There are actually fewer brown dwarfs in our cosmic neighborhood than previously thought. Rather than one star for every brown dwarf, there may be as many as six stars for every brown dwarf. [5] The majority of solar -type stars are single. [6] |
| 2015 |
91052 characters 8 sections 14 paragraphs 3 images 254 internal links 47 external links |
1. Claimed periodicity of mass extinctions 2. Development of the Nemesis hypotheses |
nemesis 0.592 brown 0.240 extinction 0.224 muller 0.207 raup 0.184 sepkoski 0.184 periodicity 0.182 sedna 0.182 dwarf 0.164 wise 0.128 star 0.121 bambach 0.110 melott 0.110 stars 0.105 dwarfs 0.087 |
Template:Distinguish2 Nemesis is a hypothetical red dwarf [1] or brown dwarf , [2] originally postulated in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years ), [2] 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. [2] [3] As of 2012 [update] , over 1800 brown dwarfs have been identified and none of them are inside the Solar System . [4] There are actually fewer brown dwarfs in our cosmic neighborhood than previously thought. Rather than one star for every brown dwarf, there may be as many as six stars for every brown dwarf. [5] The majority of solar -type stars are single. [6] |
| 2014 |
90454 characters 8 sections 14 paragraphs 3 images 252 internal links 46 external links |
1. Claimed periodicity of mass extinctions 2. Development of the Nemesis hypotheses |
nemesis 0.584 brown 0.251 extinction 0.221 muller 0.204 raup 0.181 sepkoski 0.181 periodicity 0.180 sedna 0.179 dwarf 0.176 star 0.151 wise 0.147 bambach 0.109 melott 0.109 stars 0.103 dwarfs 0.086 |
Template:Distinguish2 Nemesis is a hypothetical red dwarf star [1] or brown dwarf , [2] originally postulated in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years ), [2] 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. [2] [3] As of 2012 [update] , over 1800 brown dwarfs have been identified and none of them are inside the Solar System . [4] There are actually fewer brown dwarfs in our cosmic neighborhood than previously thought. Rather than one star for every brown dwarf, there may be as many as six stars for every brown dwarf. [5] The majority of solar -type stars are single. [6] |
| 2013 |
86945 characters 8 sections 14 paragraphs 3 images 241 internal links 42 external links |
1. Claimed periodicity of mass extinctions 2. Development of the Nemesis hypotheses |
nemesis 0.579 brown 0.247 extinction 0.231 muller 0.213 raup 0.189 sepkoski 0.189 sedna 0.187 dwarf 0.169 periodicity 0.161 star 0.147 bambach 0.114 melott 0.114 wise 0.110 stars 0.094 dwarfs 0.090 |
Template:Distinguish2 Nemesis is a hypothetical red dwarf star [1] or brown dwarf , [2] originally postulated in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years ), [2] 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. [2] [3] As of 2012 [update] , over 1800 brown dwarfs have been identified and none of them are inside the Solar System . [4] There are actually fewer brown dwarfs in our cosmic neighborhood than previously thought. Rather than one star for every brown dwarf, there may be as many as six stars for every brown dwarf. [5] |
| 2012 |
86087 characters 8 sections 14 paragraphs 2 images 241 internal links 42 external links |
1. Claimed periodicity of mass extinctions 2. Development of the Nemesis hypotheses |
nemesis 0.580 brown 0.247 extinction 0.231 muller 0.214 raup 0.190 sepkoski 0.190 sedna 0.188 dwarf 0.169 periodicity 0.161 star 0.147 bambach 0.114 melott 0.114 wise 0.110 stars 0.094 dwarfs 0.090 |
Template:Distinguish2 Nemesis is a hypothetical red dwarf star [1] or brown dwarf , [2] originally postulated in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years ), [2] 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. [2] [3] As of 2012 [update] , over 1800 brown dwarfs have been identified and none of them are inside the Solar System . [4] There are actually fewer brown dwarfs in our cosmic neighborhood than previously thought. Rather than one star for every brown dwarf, there may be as many as six stars for every brown dwarf. [5] |
| 2011 |
85248 characters 8 sections 15 paragraphs 3 images 251 internal links 39 external links |
1. Claimed periodicity of mass extinctions 2. Development of the Nemesis hypotheses |
nemesis 0.598 extinction 0.226 muller 0.209 brown 0.197 raup 0.186 sepkoski 0.186 sedna 0.184 periodicity 0.158 dwarf 0.152 star 0.144 parallax 0.115 bambach 0.111 melott 0.111 stars 0.106 dwarfs 0.088 |
Nemesis is a hypothetical hard-to-detect red dwarf star, [1] white dwarf star [2] [ dubious ] or brown dwarf , [3] originally postulated in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years ), [3] 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. [4] [3] As of 2011 [update] , over 1300 brown dwarfs have been identified and none of them are inside the Solar System. [5] |
| 2010 |
54747 characters 8 sections 12 paragraphs 3 images 220 internal links 16 external links |
1. Claimed periodicity of mass extinctions 2. Development of the Nemesis hypotheses 3. Other possible evidence: questions about orbital path of Sedna 4. Current and pending scientific searches for Nemesis |
nemesis 0.415 sedna 0.279 extinction 0.275 dwarf 0.216 muller 0.207 raup 0.193 sepkoski 0.193 star 0.192 brown 0.184 oort 0.168 periodicity 0.137 tyche 0.109 whitmire 0.109 sun 0.104 events 0.094 |
Nemesis is a hypothetical hard-to-see red dwarf star or brown dwarf , orbiting the Sun at a distance of about 50,000 to 100,000 AU (about 0.8-1.5 light-years ), somewhat beyond the Oort cloud . [1] This star was originally postulated to exist as part of a hypothesis to explain a perceived cycle of mass extinctions in the geological record , which seem to occur once every 27 million years or so. In addition, observations by astronomers of the sharp edges of Oort clouds, similar to that of the Solar System, around various binary (double) star systems, in contrast to the diffuse edges of the Oort clouds around single-star systems, has prompted some scientists to postulate that a dwarf star may be co-orbiting the Sun. [1] Counter-theories also exist that other forces (like the angular effect of the galactic gravity plane) may be the cause of the sharp-edged Oort cloud pattern around the Sun. To date the issue remains unsettled in the scientific community. |
| 2009 |
21943 characters 7 sections 7 paragraphs 1 images 41 internal links 14 external links |
1. Claimed periodicity of mass extinctions |
nemesis 0.427 extinction 0.370 muller 0.244 raup 0.228 sepkoski 0.228 periodicity 0.215 whitmire 0.192 dwarf 0.170 jackson 0.161 star 0.136 oort 0.119 events 0.111 hypothesis 0.102 brown 0.093 albert 0.089 |
Nemesis is a hypothetical red dwarf star or brown dwarf , orbiting the Sun at a distance of about 50,000 to 100,000 AU , somewhat beyond the Oort cloud . This star was originally postulated to exist as part of a hypothesis to explain a perceived cycle of mass extinctions in the geological record , which seem to occur once every 26 million years or so. |
| 2008 |
24122 characters 8 sections 12 paragraphs 1 images 47 internal links 15 external links |
1. Claimed periodicity of mass extinctions |
nemesis 0.597 extinction 0.313 periodicity 0.202 star 0.187 muller 0.184 raup 0.171 sepkoski 0.171 whitmire 0.145 dwarf 0.127 jackson 0.121 companion 0.120 oort 0.119 niven 0.103 lucifer 0.096 hammer 0.096 |
Nemesis is a hypothetical red dwarf star or brown dwarf , orbiting the Sun at a distance of about 50,000 to 100,000 AU , somewhat beyond the Oort cloud . The existence of this star was postulated in an attempt to explain an inferred periodicity in the rate of biological extinction in the geological record . |
| 2007 |
20984 characters 7 sections 10 paragraphs 0 images 39 internal links 13 external links |
1. Claimed periodicity of mass extinctions |
nemesis 0.582 extinction 0.331 periodicity 0.213 muller 0.194 raup 0.181 sepkoski 0.181 star 0.162 whitmire 0.153 dwarf 0.135 jackson 0.128 oort 0.126 niven 0.109 lucifer 0.102 hammer 0.102 events 0.088 |
Nemesis is a hypothetical red dwarf or brown dwarf star , orbiting the Sun at a distance of about 50,000 to 100,000 AU , somewhat beyond the Oort cloud . The existence of this star was postulated in an attempt to explain an inferred periodicity in the rate of biological extinction in the geological record . |
| 2006 |
10776 characters 4 sections 6 paragraphs 0 images 27 internal links 9 external links |
nemesis 0.641 muller 0.291 whitmire 0.245 jackson 0.205 dwarf 0.189 hut 0.145 308 0.131 star 0.129 715 0.122 brown 0.118 oort 0.113 davis 0.105 extinctions 0.096 comets 0.083 apogees 0.072 |
Nemesis is a hypothetical red dwarf star or brown dwarf , orbiting the Sun at a distance of about 50,000 to 100,000 AU , somewhat beyond the Oort cloud . Richard A. Muller suggests that the most likely object is a red dwarf with magnitude between 7 and 12 [1] , while Daniel P. Whitmire and Albert A. Jackson argue for a brown dwarf. Such a bright red dwarf would undoubtedly already be in existing star catalogs, but its true nature would only be detectable by measuring its parallax ; due to orbiting the Sun it would have a very low proper motion and would escape detection by proper motion surveys that have found stars like the 9th magnitude Barnard's star . |
|
| 2005 |
6582 characters 2 sections 6 paragraphs 0 images 23 internal links 7 external links |
nemesis 0.597 muller 0.199 oort 0.193 star 0.184 extinctions 0.164 dwarf 0.138 hut 0.124 raup 0.124 sepkoski 0.124 proper 0.117 717 0.112 308 0.112 observationally 0.112 cloud 0.109 catalogs 0.104 |
Nemesis is the name given to a hypothetical red dwarf star or brown dwarf , orbiting the Sun at a distance of about 50,000 to 100,000 AU , somewhat beyond the Oort cloud . Richard A. Muller suggests that the most likely object is a red dwarf with magnitude between 7 and 12 [1] . Such a bright object would undoubtedly already be in existing star catalogs, but its true nature would only be detectable by measuring its parallax ; due to orbiting the Sun it would have a very low proper motion and would escape detection by proper motion surveys that have found stars like the 9th magnitude Barnard's star . |
|
| 2004 |
2809 characters 1 sections 4 paragraphs 0 images 12 internal links 2 external links |
nemesis 0.672 extinctions 0.277 oort 0.217 raup 0.209 sepkoski 0.209 muller 0.168 disrupting 0.152 periodicity 0.148 theory 0.136 existence 0.129 cloud 0.122 disputed 0.117 companion 0.110 26 0.108 occurrence 0.107 |
Nemesis is the name given to a theoretical companion star or brown dwarf orbiting the Sun at a distance of about 50,000 to 100,000 AU , somewhat beyond the Oort cloud . |
|
| 2003 |
1984 characters 0 sections 3 paragraphs 0 images 9 internal links 0 external links |
nemesis 0.709 extinction 0.215 oort 0.184 raup 0.176 sepkoski 0.176 periodically 0.169 muller 0.142 discredited 0.136 disrupting 0.128 asimov 0.125 motivation 0.122 extinctions 0.117 isaac 0.109 careful 0.109 recurring 0.107 |
Nemesis is the name given to a theoretical companion star or brown dwarf orbiting the Sun at a great distance beyond the Oort cloud , which periodically (roughly every 24 million years), passes through a denser region of the Oort cloud, disrupting the orbits of comets , sending them into collision with the Earth and the other planets . |
|
| 2002 |
1500 characters 0 sections 1 paragraphs 0 images 7 internal links 0 external links |
nemesis 0.687 oort 0.296 discredited 0.220 credible 0.207 disrupting 0.207 extinctions 0.188 recurring 0.173 cloud 0.167 companion 0.150 periodically 0.137 theoretical 0.132 denser 0.127 passes 0.115 sending 0.113 millions 0.109 |
Nemesis is the name given to a theoretical companion star orbiting the Sun at a great distance beyond the Oort cloud , which periodically (on a scale of millions of years), passes through a denser region of the Oort cloud, disrupting the orbits of comets , sending them into collision with the Earth and the other planets . Nemesis was proposed to explain the recurring mass extinctions on Earth, but this theory has been discredited. There is no credible evidence for the existence of Nemesis. |