Editing Island of stability (section)

==Possible natural occurrence==
{{see also|Extinct isotopes of superheavy elements}}
Even though half-lives of hundreds or thousands of years would be relatively long for superheavy elements, they are far too short for any such nuclides to exist [[primordial nuclide|primordially]] on Earth. Additionally, instability of nuclei intermediate between primordial actinides ([[thorium-232|<sup>232</sup>Th]], [[uranium-235|<sup>235</sup>U]], and [[uranium-238|<sup>238</sup>U]]) and the island of stability may inhibit production of nuclei within the island in [[r-process|''r''-process]] nucleosynthesis. Various models suggest that spontaneous fission will be the dominant decay mode of nuclei with ''A''&nbsp;>&nbsp;280, and that neutron-induced or beta-delayed [[nuclear fission|fission]]—respectively neutron capture and beta decay immediately followed by fission—will become the primary reaction channels. As a result, beta decay towards the island of stability may only occur within a very narrow path or may be entirely blocked by fission, thus precluding the synthesis of nuclides within the island.<ref name="natural">{{cite journal |last1=Petermann |first1=I. |last2=Langanke |first2=K. |last3=Martínez-Pinedo |first3=G. |last4=Panov |first4=I. V. |last5=Reinhard |first5=P. G. |last6=Thielemann |first6=F. K. |display-authors=3 |date=2012 |title=Have superheavy elements been produced in nature? |url=https://www.researchgate.net/publication/229156774 |journal=European Physical Journal A |language=en |volume=48 |issue=122 |page=122 |arxiv=1207.3432 |bibcode=2012EPJA...48..122P |doi=10.1140/epja/i2012-12122-6 |s2cid=119264543}}</ref> The non-observation of superheavy nuclides such as <sup>292</sup>Hs and <sup>298</sup>Fl in nature is thought to be a consequence of a low yield in the ''r''-process resulting from this mechanism, as well as half-lives too short to allow measurable quantities to persist in nature.<ref name=spectrometry>{{cite journal| last1=Ludwig |first1=P. |last2=Faestermann |first2=T. |last3=Korschinek |first3=G. |last4=Rugel |first4=G. |last5=Dillmann |first5=I. |last6=Fimiani |first6=L. |last7=Bishop |first7=S. |last8=Kumar |first8=P. |display-authors=3 |title=Search for superheavy elements with 292&nbsp;≤&nbsp;''A''&nbsp;≤&nbsp;310 in nature with accelerator mass spectrometry |date=2012 |journal=Physical Review C |volume=85 |issue=2 |pages=024315-1–024315-8 <!-- Deny Citation Bot-->|doi=10.1103/PhysRevC.85.024315 |url=https://www.nucastro.ph.tum.de/fileadmin/tuphena/www/pubs/e024315.pdf |archive-url=https://web.archive.org/web/20181228223425/https://www.nucastro.ph.tum.de/fileadmin/tuphena/www/pubs/e024315.pdf |archive-date=28 December 2018 |url-status=live}}</ref>{{efn|The observation of long-lived isotopes of [[roentgenium]] (with ''A''&nbsp;{{=}}&nbsp;261, 265) and [[unbibium]] (''A''&nbsp;{{=}}&nbsp;292) in nature has been claimed by Israeli physicist [[Amnon Marinov]] et al.,<ref name="rg2009">{{cite journal |last1=Marinov |first1=A. |last2=Rodushkin |first2=I. |last3=Pape |first3=A. |last4=Kashiv |first4=Y. |last5=Kolb |first5=D. |last6=Brandt |first6=R. |last7=Gentry |first7=R. V. |last8=Miller |first8=H. W. |last9=Halicz |first9=L. |first10=I. |last10=Segal |year=2009 |display-authors=3 |title=Existence of Long-Lived Isotopes of a Superheavy Element in Natural Au |journal=[[International Journal of Modern Physics E]] |volume=18 |number=3 |pages=621–629 |publisher=[[World Scientific Publishing Company]] |doi=10.1142/S021830130901280X |url=http://www.phys.huji.ac.il/~marinov/publications/Au_paper_IJMPE_73.pdf |access-date=12 February 2012 |arxiv=nucl-ex/0702051 |bibcode=2009IJMPE..18..621M |s2cid=119103410 |archive-url=https://web.archive.org/web/20140714210340/http://www.phys.huji.ac.il/~marinov/publications/Au_paper_IJMPE_73.pdf |archive-date=14 July 2014 |url-status=dead }}</ref><ref name=arxiv122>{{cite journal |last=Marinov |first=A. |author2=Rodushkin, I.|author3= Kolb, D.|author4= Pape, A.|author5= Kashiv, Y.|author6= Brandt, R.|author7= Gentry, R. V.|author8= Miller, H. W. |display-authors=3 |title=Evidence for a long-lived superheavy nucleus with atomic mass number A&nbsp;=&nbsp;292 and atomic number Z&nbsp;=~&nbsp;122 in natural Th |journal= International Journal of Modern Physics E|year=2010 |arxiv=0804.3869 |bibcode = 2010IJMPE..19..131M |doi = 10.1142/S0218301310014662 |volume=19 |issue=1 |pages=131–140 |s2cid=117956340 }}</ref> though evaluations of the technique used and subsequent unsuccessful searches cast considerable doubt on these results.<ref name=emsley/><ref name=nat-scint/>}} Various studies utilizing [[accelerator mass spectroscopy]] and [[crystal scintillator]]s have reported upper limits of the natural abundance of such long-lived superheavy nuclei on the order of {{val|e=-14}} relative to their stable [[homolog (chemistry)|homologs]].<ref name=nat-scint>{{cite journal |last1=Belli |first1=P. |last2=Bernabei |first2=R. |last3=Cappella |first3=F. |last4=Caracciolo |first4=V. |last5=Cerulli |first5=R. |last6=Danevich |first6=F. A. |last7=Incicchitti |first7=A. |last8=Kasperovych |first8=D. V.|last9=Kobychev |first9=V. V. |last10=Laubenstein |first10=M. |last11=Poda |first11=D. V. |last12=Polischuk |first12=O. G. |last13=Sokur |first13=N. V. |last14=Tretyak |first14=V. I. |display-authors=3 |title=Search for naturally occurring seaborgium with radiopure <sup>116</sup>CdWO<sub>4</sub> crystal scintillators |date=2022 |journal=Physica Scripta |volume=97 |number=85302 |page=085302 |doi=10.1088/1402-4896/ac7a6d|bibcode=2022PhyS...97h5302B |s2cid=249902412 }}</ref>

Despite these obstacles to their synthesis, a 2013 study published by a group of Russian physicists led by [[Valeriy Zagrebaev]] proposes that the longest-lived copernicium isotopes may occur at an abundance of 10<sup>−12</sup> relative to lead, whereby they may be detectable in [[cosmic ray]]s.<ref name=Zagrebaev /> Similarly, in a 2013 experiment, a group of Russian physicists led by Aleksandr Bagulya reported the possible observation of three [[cosmogenic]] superheavy nuclei in [[olivine]] crystals in meteorites. The atomic number of these nuclei was estimated to be between 105 and 130, with one nucleus likely constrained between 113 and 129, and their lifetimes were estimated to be at least 3,000 years. Although this observation has yet to be confirmed in independent studies, it strongly suggests the existence of the island of stability, and is consistent with theoretical calculations of half-lives of these nuclides.<ref name=oly1>{{cite journal |last1=Bagulya |first1=A. V. |last2=Vladimirov |first2=M. S. |last3=Volkov |first3=A. E. |last4=Goncharova |first4=L. A. |last5=Gorbunov |first5=S. A. |last6=Kalinina |first6=G. V. |last7=Konovalova |first7=N. S. |last8=Okatyeva |first8=N. M. |last9=Pavolva |first9=T. A. |last10=Polukhina |first10=N. G. |last11=Starkov |first11=N. I. |last12=Soe |first12=T. N. |last13=Chernyavsky |first13=M. M. |last14=Shchedrina |first14=T. V. |display-authors=3 |title=Charge spectrum of superheavy nuclei of galactic cosmic rays obtained in the OLIMPIA experiment |journal=Bulletin of the Lebedev Physics Institute |date=2015 |volume=42 |issue=5 |pages=152–156 |doi=10.3103/S1068335615050073 |url=https://www.researchgate.net/publication/279166139|bibcode=2015BLPI...42..152B |s2cid=124044490 }}</ref><ref name=nats>{{cite arXiv |first1=A.  |last1= Alexandrov |first2= V. |last2= Alexeev |first3= A. |last3= Bagulya |first4= A. |last4= Dashkina |first5= M. |last5= Chernyavsky |first6= A. |last6= Gippius |first7= L. |last7= Goncharova |first8= S. |last8= Gorbunov |first9= V. |last9= Grachev |first10= G. |last10= Kalinina |first11= N. |last11= Konovalova |first12= N. |last12= Okateva |first13= T. |last13= Pavlova |first14= N. |last14= Polukhina |first15= R. |last15= Rymzhanov |first16= N. |last16= Starkov |first17= T. N. |last17= Soe |first18= T. |last18= Shchedrina |first19= A. |last19= Volkov |display-authors=3 |title=Natural superheavy nuclei in astrophysical data |date=2019 |eprint=1908.02931 |class=nucl-ex }}</ref><ref name=19cq>{{cite journal |title=Superheavy elements: Oganesson and beyond |date=2019 |last1=Giuliani |first1=S. A. |last2=Matheson |first2=Z. |last3=Nazarewicz |first3=W. |display-authors=et al. |journal=Reviews of Modern Physics |volume=91 |issue=1 |pages=24–27 |doi=10.1103/RevModPhys.91.011001 |osti=1513815 |doi-access=free }}</ref>

The decay of heavy, long-lived elements in the island of stability is a proposed explanation for the unusual presence of the short-lived [[Radionuclide|radioactive isotopes]] observed in [[Przybylski's Star]].<ref>{{Cite journal |author1=V. A. Dzuba |author2=V. V. Flambaum |author3=J. K. Webb |year=2017 |title=Isotope shift and search for metastable superheavy elements in astrophysical data |journal=Physical Review A |volume=95 |issue=6 |pages=062515 |arxiv=1703.04250 |bibcode=2017PhRvA..95f2515D |doi=10.1103/PhysRevA.95.062515 |s2cid=118956691}}</ref>