Editing Wow! signal (section)

== Celestial location ==
[[File:Wow! signal source.svg|thumb|upright=1.8|The two regions of space in the constellation [[Sagittarius (constellation)|Sagittarius]] from where the Wow! signal may have originated. The ambiguity is due to how the telescope was designed. For clarity, the widths (right ascension) of the red bands have been exaggerated.]]
The precise location in the sky where the signal apparently originated is uncertain due to the design of the [[Big Ear]] telescope, which featured two [[feed horn]]s, each receiving a beam from slightly different directions, while following Earth's rotation. The Wow! signal was detected in one beam but not in the other, and the data was processed in such a way that it is impossible to determine which of the two horns received the signal.<ref name="feedhorns">{{Cite web |title=Big Ear's Twin Feed Horns |url=http://www.bigear.org/hshorns.htm |access-date=July 2, 2016}}</ref> There are, therefore, two possible [[right ascension]] (RA) values for the location of the signal (expressed below in terms of the two main [[Equatorial coordinate system|reference systems]]):<ref name="gray_2001">{{Cite journal |last1=Gray |first1=Robert |last2=Marvel |first2=Kevin |year=2001 |title=A VLA Search for the Ohio State 'Wow' |url=http://www.bigear.org/Gray-Marvel.pdf |journal=[[The Astrophysical Journal]] |volume=546 |issue=2 |pages=1171–77 |bibcode=2001ApJ...546.1171G |doi=10.1086/318272 |s2cid=17141857}}</ref>

{| class="wikitable" style="border: none;"
|-
|style="border: none; background: white;"|
! [[B1950]] equinox
! [[J2000]] equinox
|-
! RA (positive horn)
| {{nowrap|19<sup>h</sup>22<sup>m</sup>24.64<sup>s</sup> ± 5<sup>s</sup>}}
| {{nowrap|19<sup>h</sup>25<sup>m</sup>31<sup>s</sup> ± 10<sup>s</sup>}}
|-
! RA (negative horn)
| {{nowrap|19<sup>h</sup>25<sup>m</sup>17.01<sup>s</sup> ± 5<sup>s</sup>}}
| {{nowrap|19<sup>h</sup>28<sup>m</sup>22<sup>s</sup> ± 10<sup>s</sup>}}
|}

In contrast, the [[declination]] was unambiguously determined to be as follows:

{| class="wikitable" style="border: none"
|-
|style="border: none; background: white"|
! scope="col" | B1950 equinox
! scope="col" | J2000 equinox
|-
! scope="row" | Declination
| {{nowrap|−27°03′ ± 20′}}
| {{nowrap|−26°57′ ± 20′}}
|}

The [[galactic coordinates]] for the positive horn are {{math|''l''}}=11.7°, {{math|''b''}}=−18.9°, and for the negative horn {{math|''l''}}=11.9°, {{math|''b''}}=−19.5°, both being therefore about 19° toward the southeast of the galactic plane, and about 24° or 25° east of the [[Galactic Center]]. The region of the sky in question lies northwest of the [[Messier 55|globular cluster M55]], in the constellation [[Sagittarius (constellation)|Sagittarius]], roughly 2.5&nbsp;degrees south of the [[Magnitude (astronomy)|fifth-magnitude]] star group [[Chi Sagittarii]], and about 3.5&nbsp;degrees south of the plane of the [[ecliptic]]. The closest easily visible star is [[Tau Sagittarii]].<ref name="30thwow">{{Cite web |last=Ehman |first=Jerry R. |date=May 28, 2010 |title=The Big Ear Wow! Signal (30th Anniversary Report) |url=http://www.bigear.org/Wow30th/wow30th.htm |access-date=July 2, 2016 |publisher=North American AstroPhysical Observatory}}</ref>

Initially, no nearby Sun-like stars were known to lie within the antenna coordinates, although in any direction the antenna pattern would encompass about six distant Sun-like stars as estimated in 2016.<ref name="Calib Wow"/>  In 2022, a paper published in the ''[[International Journal of Astrobiology]]'' identified three likely Sun-like stars within the antenna-pointed coordinates. The better characterized star, [[2MASS 19281982-2640123]], is located 1,800 light years away, only 132 light years away from Maccone's estimation where an intelligent civilization is more likely to exist.<ref>{{Cite report |url=https://www.dia.mil/FOIA/FOIA-Electronic-Reading-Room/FileId/170023/ |title=Statistical drake equation |last=Maccone |first=Claudio |publisher=Defense Intelligence Agency |year=2009}}</ref> The other two candidates, 2MASS 19252173-2713537 and 2MASS 19282229-2702492, were insufficiently characterized but still likely to be Sun-like stars. Also, 14 other catalogued stars at the antenna coordinates may still turn out to be similar to the Sun after more data becomes available.<ref>{{Cite journal |last=Caballero |first=Alberto |year=2022 |title=An approximation to determine the source of the WOW! Signal |url=https://www.cambridge.org/core/journals/international-journal-of-astrobiology/article/an-approximation-to-determine-the-source-of-the-wow-signal/4C58B6292C73FE8BF04A06C67BAA5B1A |journal=International Journal of Astrobiology |volume=21 |issue=3 |pages=129–136 |arxiv=2011.06090 |bibcode=2022IJAsB..21..129C |doi=10.1017/S1473550422000015 |issn=1473-5504 |s2cid=226307031}}</ref><ref>{{Cite news |last=Anderson |first=Paul Scott |date=December 2, 2020 |title=Did the Wow! signal come from this star? |url=https://earthsky.org/space/source-of-wow-signal-in-1977-sunlike-star-2mass-19281982-2640123/ |access-date=May 14, 2022 |work=EarthSky}}</ref><ref>{{Cite news |last=Mann |first=Adam |date=May 24, 2022 |title=Famous 'alien' Wow! signal may have come from distant, sunlike star |url=https://www.space.com/wow-signal-origin-star |access-date=June 9, 2022 |work=Space.com}}</ref> As a response to the discovery, [[Breakthrough Listen]] conducted the first targeted search for the Wow! Signal in its first collaboration between the Green Bank Telescope and the Allen Telescope Array of the SETI Institute.<ref>{{Cite web |date=September 29, 2022 |title=1st Coordinated Green Bank Telescope/Allen Telescope Array Observes Possible Source of the WOW! Signal |url=https://www.seti.org/1st-coordinated-green-bank-telescopeallen-telescope-array-observes-possible-source-wow-signal |publisher=SETI}}</ref><ref>{{Cite news |last=Howell |first=Elizabeth |date=November 7, 2022 |title=No signs of alien life found near source of famous 'Wow!' signal |url=https://www.space.com/seti-wow-signal-search-no-life-signs |access-date=November 9, 2022 |work=Space.com}}</ref> The observations were performed on May 21, 2022, lasting 1 hour from Greenbank, 35 minutes from ATA, and 9 minutes and 40 seconds simultaneously.<ref>{{Cite journal |last1=Perez |first1=Karen I. |last2=Farah |first2=Wael |last3=Sheikh |first3=Sofia Z. |last4=Croft |first4=Steve |last5=Siemion |first5=Andrew |last6=Pollak |first6=Alexander W. |last7=Brzycki |first7=Bryan |last8=Cruz |first8=Luigi F. |last9=Czech |first9=Daniel |last10=DeBoer |first10=David |last11=Drew |first11=Jamie |last12=Gajjar |first12=Vishal |last13=Garrett |first13=Michael A. |last14=Isaacson |first14=Howard |last15=Lebofsky |first15=Matt |date=September 26, 2022 |title=Breakthrough Listen Search for the WOW! Signal* |journal=Research Notes of the AAS |volume=6 |issue=9 |pages=197 |bibcode=2022RNAAS...6..197P |doi=10.3847/2515-5172/ac9408 |issn=2515-5172 |s2cid=252540293 |doi-access=free}}</ref> No technosignature candidates were found.<ref>{{Cite web |title=Breakthrough Listen Search for the WOW! Signal |url=https://seti.berkeley.edu/wow/ |access-date=November 9, 2022 |website=Berkeley SETI Research Center |publisher=University of California}}</ref>