Editing First light (astronomy)

{{Short description|Term in astronomy for the first time a telescope is used to look at the Universe}}
{{about|the testing of telescopes|the first light of dawn|Twilight#Nautical twilight|the cosmogonical age|first light (cosmology)}}
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|Description =First light image from the [[Kepler space telescope]]<ref name=kepler>{{cite web|last=Atkinson|first=Nancy|title=Kepler's "First Light" Images|date=16 April 2009|url=http://www.universetoday.com/29258/keplers-first-light-images/|publisher=[[Universe Today]]|access-date=2012-10-13}}</ref>
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In [[astronomy]], '''first light''' is the first use of a [[telescope]] (or, in general, a new instrument) to take an [[astrophotography|astronomical image]] after it has been constructed. This is often not the first viewing using the telescope; optical tests will probably have been performed to adjust the components.

==Characteristics==
The first light image is normally of little scientific interest and is of poor quality, since the various telescope elements are yet to be adjusted for optimum efficiency. Despite this, a first light is always a moment of great excitement, both for the people who design and build the telescope and for the astronomical community, who may have anticipated the moment for many years while the telescope was under construction. A well-known and spectacular [[astronomical object]] is usually chosen as a subject.{{citation needed|date=July 2019}}

==Historical examples==
[[File:IRIS first light SJI image.jpg|thumb|The Sun in the first light image from the IRIS satellite]]

The famous {{convert|200|in|m|order=flip|adj=on|2}} [[Hale Telescope]] of [[Palomar Observatory]] saw first light on 26 January 1949, targeting [[NGC 2261]]<ref>{{cite web|url=http://365daysofastronomy.org/2009/01/26/january-26-60th-anniversary-of-hale-telescope-first-light/ |title=January 26: 60th Anniversary of Hale Telescope "First Light" |publisher=365daysofastronomy.org |date=2009-01-26 |access-date=2012-02-04 |last=Kardel |first=Scott}}</ref> under the direction of American astronomer [[Edwin Powell Hubble]]. The image was published in many magazines and is available on Caltech Archives.{{citation needed|date=July 2019}}

The [[Isaac Newton Telescope]] had two first lights: one in England in 1965 with its original mirror, and another in 1984 at La Palma island.<ref name="ing">{{Cite web|url=http://www.ing.iac.es/PR/chronology.html|title = Chronology of the Isaac Newton Group of Telescopes}}</ref> The second first light was done with a video camera that showed the [[Crab Pulsar]] flashing.<ref name=light>{{cite journal|title=First light on La Palma|url=https://archive.org/details/bub_gb_rot6QG6G6bgC|journal=New Scientist|date=16 February 1984|publisher=[[Reed Business Information]]|first=Nigel|last=Henbest |page=[https://archive.org/details/bub_gb_rot6QG6G6bgC/page/n17 16]}}</ref>

Elation at first light images by the [[Hubble Space Telescope]] in 1990 soon gave way to initial disappointment when a flaw prevented adjustments for proper operation. The expected first light image quality was finally achieved after a [[STS-61|1993 servicing mission]] by [[Space Shuttle Endeavour|Space Shuttle ''Endeavour'']].

The [[Large Binocular Telescope]] had its first light with a single primary mirror on 12 October 2005, which was a view of [[NGC 891]].<ref>{{cite web |author=Staff |title=First Light |url=http://medusa.as.arizona.edu/lbto/first_light.htm |date=12 October 2005 |website=[[University of Arizona]] |archive-url=https://web.archive.org/web/20081202105302/http://medusa.as.arizona.edu/lbto/first_light.htm |archive-date=2008-12-02}}</ref><ref>{{cite web |url=http://www.spaceref.com/news/viewpr.html?pid=18115 |title=Large Binocular Telescope Successfully Achieves First Light |publisher=SpaceRef.com |date=2005-10-26 |access-date=2012-02-04 |archive-date=2019-07-12 |archive-url=https://web.archive.org/web/20190712232742/http://www.spaceref.com/news/viewpr.html?pid=18115 |url-status=dead }}</ref> The second primary mirror was installed in January 2006 and became fully operational in January 2008.<ref name="BBC">{{cite news |url=http://news.bbc.co.uk/1/hi/sci/tech/7282385.stm |title= Giant telescope opens both eyes |access-date=2008-03-06 | date=2008-03-06 | location=London | work=[[BBC News]]}}</ref>

The {{convert|10.4|m|cm|adj=on}} [[Gran Telescopio Canarias]] had a first light image of Tycho 1205081 on 14 July 2007.<ref name="backreaction">{{cite web|url=http://backreaction.blogspot.sg/2007/07/first-light-for-gran-telescopio.html|title=First Light for the Gran Telescopio Canarias|date=14 July 2007|access-date=2015-10-03}}</ref>

The [[Interface Region Imaging Spectrograph|IRIS]] solar space observatory achieved first light on 17 July 2013.<ref name=iris>{{cite web|url=http://www.nasa.gov/content/goddard/iris-telescope-first-glimpse-of-suns-mysterious-atmosphere/index.html|title=IRIS Telescope's First Look at Sun Atmosphere|first=Holly|last=Zell|date=9 March 2015|access-date=29 July 2013|archive-date=10 September 2015|archive-url=https://web.archive.org/web/20150910093524/http://www.nasa.gov/content/goddard/iris-telescope-first-glimpse-of-suns-mysterious-atmosphere/index.html|url-status=dead}}</ref> The [[principal investigator|PI]] noted: <blockquote>"The quality of images and spectra we are receiving from IRIS is amazing. This is just what we were hoping for ..."<ref name=iris/></blockquote>

On 4 February 2022, the first light viewed by the [[James Webb Space Telescope]] (JWST) was from the star [[HD 84406]] for the purpose of testing and aligning the focus of the [[Optical Telescope Element|telescope's 18 mirrors]].<ref name="GZM-20220204">{{cite news |last=Dvorsky |first=George |title=Webb Space Telescope Successfully Sees Its First Glimmer of Light - HD 84406 will go down in history as the first star spotted by the $10 billion space telescope. |url=https://gizmodo.com/james-webb-space-telescop-first-star-light-hd-84406-1848480785 |date=4 February 2022 |work=[[Gizmodo]] |accessdate=5 February 2022 }}</ref><ref name="FT-20220206">{{cite news |last=Hood |first=Abby Lee |title=The James Webb Space Telescope Just Detected Its First Signal - We're Watching The Future Unfold In Real Time |url=https://futurism.com/the-byte/james-webb-telescope-first-signal |date=6 February 2022 |work=Futurism.com |accessdate=6 February 2022 }}</ref> On 11 February 2022. ''[[The New York Times]]'' reported that "first light" images from the James Webb Space Telescope were released - as well as a related [https://www.youtube.com/watch?v=QlwatKpla8s NASA alignment video (2/11/2022; 3:00)].<ref name="NYT-20220211">{{cite news |last=Overbye |first=Dennis |authorlink=Dennis Overbye |title=James Webb Telescope Sends Home a Selfie and 18 Images of Starlight - The spacecraft recorded a series of images of a target star that will be used to help its mirrors prepare for scientific research. |url=https://www.nytimes.com/2022/02/11/science/webb-telescope-selfie-pictures.html |date=11 February 2022 |work=[[The New York Times]] |accessdate=12 February 2022 }}</ref> On 6 July 2022, NASA released a test image from the JWST's Fine Guidance Sensor.<ref name="WSJ-20220708">{{cite news |last=Woodward |first=Aylin |title=NASA Reveals Dazzling Test Image From James Webb Space Telescope - Mission scientists said the image is among the deepest ever taken of the universe |url=https://www.wsj.com/articles/nasa-reveals-dazzling-test-image-from-james-webb-space-telescope-11657310145 |date=8 July 2022 |work=[[The Wall Street Journal]] |accessdate=9 July 2022 }}</ref> NASA released the first official JWST image on 11 July 2022.<ref name="NASA-20220711">{{cite news |last=Garner |first=Rob |title=NASA's Webb Delivers Deepest Infrared Image of Universe Yet |url=https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-delivers-deepest-infrared-image-of-universe-yet |date=11 July 2022 |work=[[NASA]] |accessdate=12 July 2022 }}</ref><ref name="NYT-20220711">{{cite news |last1=Overbye |first1=Dennis |last2=Chang |first2=Kenneth |last3=Tankersley |first3=Jim |title=Biden and NASA Share First Webb Space Telescope Image - From the White House on Monday, humanity got its first glimpse of what the observatory in space has been seeing: a cluster of early galaxies. |url=https://www.nytimes.com/2022/07/11/science/nasa-webb-telescope-images-livestream.html |date=11 July 2022 |work=[[The New York Times]] |accessdate=12 July 2022 }}</ref> Later, in an official ceremony, the first collection of five JWST science images were released on Tuesday, 12 July 2022 (NASA-TV live; 10:30 am/et/usa).<ref name="NASA-20220614">{{cite news |last1=Fisher |first1=Alise |last2=Pinot |first2=Natasha |last3=Betz |first3=Laura |last4=Dodson |first4=Gerelle |title =MEDIA ADVISORY M22-084 - NASA Invites Media, Public to View Webb Telescope's First Images |url=https://www.nasa.gov/press-release/nasa-invites-media-public-to-view-webb-telescope-s-first-images |date=14 June 2022 |work=[[NASA]] |accessdate=29 June 2022 }}</ref><ref name="AT-20220629">{{cite news |last=Berger |first=Eric |title=NASA scientists say images from the Webb telescope nearly brought them to tears - Deep field images of the universe, exoplanet atmospheres, and more to be unveiled. |url=https://arstechnica.com/science/2022/06/nasa-teases-extraordinary-images-captured-by-its-webb-telescope/ |date=29 June 2022 |work=[[Ars Technica]] |accessdate=29 June 2022 }}</ref>{{-}}
{{multiple image |header=[[James Webb Space Telescope]] "First Light" images (7/12/2022) |direction=horizontal |align=center |width= |image1=Webb's First Deep Field.jpg |caption1= |width1=100 |image2=NASA’s Webb Reveals Cosmic Cliffs, Glittering Landscape of Star Birth.jpg |caption2= |width2=175 |image3=NASA’s Webb Captures Dying Star’s Final ‘Performance’ in Fine Detail.png |caption3= |width3=220 |image4=Stephan's Quintet taken by James Webb Space Telescope.jpg |caption4= |width4=107|image5=Stephan’s Quintet (MIRI Imaging).png |caption5= |width5=123 |image6=Exoplanet WASP-96 b (NIRISS Transmission Spectrum) (weic2206a).jpeg |caption6= |width6=150 |footer= }}

== Gallery ==

<gallery class="center" mode="packed" heights="200px" caption="">
File:NGC 5317 (also NGC 5364).jpg|[[Very Large Telescope]]'s wide field imager [[VIMOS]] takes its first light image of [[NGC 5364]].
File:Hubble First Light, First Released Image (STScI-1990-04a).png|[[Hubble Space Telescope]]'s first light with its impaired [[Wide Field and Planetary Camera|WFPC]], 1990
File:Tarantula Nebula TRAPPIST.jpg|First light of the [[Tarantula Nebula]] by [[TRAPPIST]]
File:WISPR first light image.png|First light of [[WISPR]] on the [[Parker Solar Probe]], September 2018
</gallery>
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<gallery align="left" mode="packed" heights="150px">
File:James Webb Space Telescope primary mirror captured by it from Lagrange 2 point.jpg|[[Selfie]]: Primary mirror of the [[James Webb Space Telescope]] at destination.<ref name="Webb blog 2022-02-11">{{Cite web|url=https://blogs.nasa.gov/webb/2022/02/11/photons-received-webb-sees-its-first-star-18-times/|title=Photons Received: Webb Sees Its First Star – 18 Times – James Webb Space Telescope|website=Blogs.nasa.gov|access-date=12 February 2022}}</ref>
File:JWST - First images of HD 84406.png|18 images of same target star [[HD 84406]] by the 18 unfocused mirror segments.
File:JWST - First images of HD 84406 (segments marked).png|Phase 1 interim image, annotated with the related mirror segments that took each image.
File:JWST - Images of HD 84406 after phase 1 alignment.png|18 unfocused images of same target star [[HD 84406]].<ref name="Webb blog 2022-02-18">{{Cite web|url=https://blogs.nasa.gov/webb/2022/02/18/webb-team-brings-18-dots-of-starlight-into-hexagonal-formation/|title=Webb Team Brings 18 Dots of Starlight Into Hexagonal Formation|website=Blogs.nasa.gov|access-date=18 February 2022}}</ref>
File:JWST - Images of HD 84406 after phase 1 alignment (segments marked).png|Phase 1 annotated completion image of [[HD 84406]].
File:JWST commissioning - HD 84406 animated segment alignment.gif|Phase 2 completion, showing "before and after" effects of segment alignment.
File:JWST commissioning - HD 84406 after image stacking.jpg|Phase 3 completion, showing 18 segments "stacked" as a single image of [[HD 84406]].
</gallery>
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== References ==
{{reflist|2}}

[[Category:Telescopes]]
[[Category:Astrophotography| ]]
[[Category:Astronomical imaging]]