Editing Dyson sphere (section)

==Search for megastructures==
Dyson-style energy collectors around a distant star would absorb and re-radiate energy from the star. The wavelengths of such re-radiated energy may be atypical for the star's [[spectral type]], due to the presence of heavy elements not naturally occurring within the star. If the percentage of such atypical wavelengths were to be significant, an alien megastructure could be detected at interstellar distances.<ref name="search" /> This could indicate the presence of what has been called a Type{{spaces}}II [[Kardashev scale|Kardashev civilization]].<ref>{{cite conference |first=Nikolai |last=Kardashev |author-link=Nikolai Kardashev |url=http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1985IAUS..112..497K |title=On the Inevitability and the Possible Structures of Supercivilizations |conference=The search for extraterrestrial life: Recent developments; Proceedings of the Symposium, June 18–21, 1984 |location=Boston, Massachusetts, US |id=A86-38126 17–88 |publisher=Dordrecht, D. Reidel Publishing Co. |date=1985 |pages=497–504|bibcode=1985IAUS..112..497K }}</ref>

[[SETI]] has looked for such infrared-heavy spectra from [[solar analog]]s, as has [[Fermilab]].<ref name="dyson1">{{cite web| url=http://home.fnal.gov/~carrigan/infrared_astronomy/Fermilab_search.htm| title=Fermilab Dyson Sphere search program|date=February 23, 2006| access-date=2006-03-02| first=D.| last=Carrigan| publisher=Fermi National Accelerator Laboratory|archive-url=https://web.archive.org/web/20060306222359/http://home.fnal.gov/~carrigan/Infrared_Astronomy/Fermilab_search.htm| archive-date=2006-03-06| url-status=dead}}</ref><ref>{{Cite journal |last=Shostak |first=Seth |date=Spring 2009 |journal=Engineering & Science |title=When Will We Find the Extraterrestrials? |volume=72 |number=1 |pages=12–21 |issn=0013-7812 |url=http://archive.seti.org/pdfs/Shostak-spring2009-EnS.pdf <!--permalink to official source with abstract & alternate PDF link: http://resolver.caltech.edu/CaltechES:72.1.Extraterrestrials--> |url-status=dead |archive-url=https://web.archive.org/web/20150415115307/http://archive.seti.org/pdfs/Shostak-spring2009-EnS.pdf |archive-date=2015-04-15 }}</ref> Fermilab discovered 17 potential "ambiguous" candidates, of which four were in 2006 called "amusing but still questionable".<ref name="dyson1" /> Later searches also resulted in several candidates, all of which remain unconfirmed.<ref>{{cite web|author=Dick Carrigan |url=http://home.fnal.gov/~carrigan/infrared_astronomy/Other_searches.htm |title=Dyson Sphere Searches |publisher=Home.fnal.gov |date=2010-12-16 |access-date=2012-06-12}}</ref><ref>{{cite web|url=http://www.scientificamerican.com/article/alien-supercivilizations-absent-from-100-000-nearby-galaxies|title=Alien Supercivilizations Absent from 100,000 Nearby Galaxies|first=Lee|last=Billings|website=[[Scientific American]]|access-date=31 August 2017}}</ref><ref name="econ2015">{{Cite news
| title = Infra digging: Looking for aliens: The search for extraterrestrials goes intergalactic
| newspaper = The Economist
| date = 2015-04-18
| access-date = 2015-04-19
| url = https://www.economist.com/news/science-and-technology/21648607-search-extraterrestrials-goes-intergalactic-infra-digging
| quote = Fifty [galaxies] were red enough to be hosting aliens gobbling up half or more of their starlight.
}}</ref>

On 14 October 2015, [[Planet Hunters]]' citizen scientists discovered unusual light fluctuations of the star [[KIC 8462852]] raising press speculation that a Dyson sphere may have been discovered.<ref name="ATL-20151013">{{cite web| last1=Andersen| first1=Ross| title=The Most Mysterious Star in Our Galaxy| url=https://www.theatlantic.com/science/archive/2015/10/the-most-interesting-star-in-our-galaxy/410023/ |date=13 October 2015 |work=[[The Atlantic]]| access-date=13 October 2015}}</ref><ref name="IND-20151015">{{cite web| last1=Williams| first1=Lee| title=Astronomers may have found giant alien 'megastructures' orbiting star near the Milky Way| url=https://www.independent.co.uk/news/world/forget-water-on-mars-astronomers-may-have-just-found-giant-alien-megastructures-orbiting-a-star-near-a6693886.html |date=15 October 2015 |work=[[The Independent]]| access-date=15 October 2015}}</ref> However, subsequent analysis showed that the results were consistent with the presence of dust.<ref name="AXV-20180102">{{Cite journal |title=The First Post-Kepler Brightness Dips of KIC 8462852 |journal=The Astrophysical Journal |volume=853 |issue=1 |at=L8 |arxiv=1801.00732 |first1=Tabetha S. |last1=Boyajian |display-authors=etal |doi=10.3847/2041-8213/aaa405 |year=2018 |bibcode=2018ApJ...853L...8B|s2cid=215751718 |doi-access=free }}</ref><ref name="NatGeoJan3">{{cite news |url=https://news.nationalgeographic.com/2018/01/mystery-of--alien-megastructure--star-has-been-cracked/ |archive-url=https://web.archive.org/web/20180103214909/https://news.nationalgeographic.com/2018/01/mystery-of--alien-megastructure--star-has-been-cracked/ |url-status=dead |archive-date=January 3, 2018 |title=Mystery of 'Alien Megastructure' Star Has Been Cracked |work=[[National Geographic]] |last=Drake |first=Nadia |author-link=Nadia Drake |date=3 January 2018 |access-date=4 January 2018}}</ref> A further campaign in 2024 identified seven possible candidates for Dyson-spheres, but further investigation was said to be required.<ref>{{Cite web |last=Hrinko |first=Ivan |date=2024-05-14 |title=Scientists start hunting for Dyson Spheres |url=https://universemagazine.com/en/scientists-find-seven-candidates-for-dyson-spheres/ |access-date=2024-07-15 |website=Universe Space Tech |language=en-US}}</ref><ref>{{cite journal |last1=Suazo |first1=Matías |display-authors=et al |date=6 May 2024 |title=Project Hephaistos – II. Dyson sphere candidates from Gaia DR3, 2MASS, and WISE |url=https://academic.oup.com/mnras/article/531/1/695/7665761?login=false |journal=Monthly Notices of the Royal Astronomical Society |volume=531 |issue=1 |pages=695–707 |arxiv=2405.02927 |doi=10.1093/mnras/stae1186 |doi-access=free}}</ref>