Editing Hubble Space Telescope (section)

== Public use ==

=== Proposal process ===
[[File:EmissionNebula NGC6357.jpg|thumb|upright|Star cluster [[Pismis 24]] with [[NGC 6357|nebula]]]]

Anyone can apply for time on the telescope; there are no restrictions on nationality or academic affiliation, but funding for analysis is available only to U.S. institutions.{{sfn|Strolger|Rose|2017|p=11}} Competition for time on the telescope is intense, with about one-fifth of the proposals submitted in each cycle earning time on the schedule.<ref>{{cite web |url=http://www.stsci.edu/hst/HST_overview |title=HST Overview |publisher=NASA |date=June 21, 2010 |access-date=November 4, 2012 |at=Mission Operations and Observations |archive-date=July 15, 2022 |archive-url=https://web.archive.org/web/20220715150146/https://www.stsci.edu/hst |url-status=live }}</ref><ref name="Telemetry" />

Calls for proposals are issued roughly annually, with time allocated for a cycle lasting about one year. Proposals are divided into several categories; "general observer" proposals are the most common, covering routine observations. "Snapshot observations" are those in which targets require only 45 minutes or less of telescope time, including overheads such as acquiring the target. Snapshot observations are used to fill in gaps in the telescope schedule that cannot be filled by regular general observer programs.{{sfn|Strolger|Rose|2017|p=21}}

Astronomers may make "Target of Opportunity" proposals, in which observations are scheduled if a transient event covered by the proposal occurs during the scheduling cycle. In addition, up to 10% of the telescope time is designated "director's discretionary" (DD) time. Astronomers can apply to use DD time at any time of year, and it is typically awarded for study of unexpected transient phenomena such as supernovae.{{sfn|Strolger|Rose|2017|p=37}}

Other uses of DD time have included the observations that led to views of the Hubble Deep Field and Hubble Ultra Deep Field, and in the first four cycles of telescope time, observations that were carried out by amateur astronomers.<ref name="Omeara1997" /><ref name="motherboard20150424" />

In 2012, the ESA held a contest for public image processing of Hubble data to encourage the discovery of "hidden treasures" in the raw Hubble data.<ref>{{Cite web |title=Hubble's Hidden Treasures 2012 |url=https://esahubble.org/projects/hiddentreasures/ |access-date=April 7, 2022 |website=ESA/Hubble |language=en |archive-date=May 2, 2022 |archive-url=https://web.archive.org/web/20220502005140/https://esahubble.org/projects/hiddentreasures/ |url-status=live }}</ref><ref>{{Cite web |last=Goddard |first=Louis |date=August 27, 2012 |title=Hubble image processing competition creates stunning new views from old data |url=https://www.theverge.com/2012/8/27/3271105/hubble-image-processing-competition-winners |url-status=live |archive-url=https://web.archive.org/web/20220407173339/https://www.theverge.com/2012/8/27/3271105/hubble-image-processing-competition-winners |archive-date=April 7, 2022 |access-date=April 7, 2022 |website=The Verge |language=en}}</ref>

=== Use by amateur astronomers ===
[[File:Hubble Space Telescope in Orion.jpg|thumb|upright|The HST is sometimes visible from the ground, as in this 39-second exposure when it is in Orion. Maximum brightness is about magnitude 1.]]

The first director of STScI, [[Riccardo Giacconi]], announced in 1986 that he intended to devote some of his director discretionary time to allowing amateur astronomers to use the telescope. The total time to be allocated was only a few hours per cycle but excited great interest among amateur astronomers.<ref name="Omeara1997" /><ref name="motherboard20150424" />

Proposals for amateur time were stringently reviewed by a committee of amateur astronomers, and time was awarded only to proposals that were deemed to have genuine scientific merit, did not duplicate proposals made by professionals, and required the unique capabilities of the space telescope. Thirteen amateur astronomers were awarded time on the telescope, with observations being carried out between 1990 and 1997.<ref name="Omeara1997">{{cite journal |url=https://www.thefreelibrary.com/The+demise+of+the+HST+amateur+program.-a019661324 |title=The Demise of the HST Amateur Program |journal=[[Sky & Telescope]] |first=Stephen James |last=O'Meara |editor-first=Edwin L. |editor-last=Aguirre |volume=96 |issue=6 |page=97 |date=June 1997 |bibcode=1997S&T....93f..97O |access-date=February 9, 2019 |archive-date=February 9, 2019 |archive-url=https://web.archive.org/web/20190209124219/https://www.thefreelibrary.com/The+demise+of+the+HST+amateur+program.-a019661324 |url-status=live }}</ref> One such study was "[[Hubble search for transition comets|Transition Comets—UV Search for OH]]". The first proposal, "A Hubble Space Telescope Study of Posteclipse Brightening and Albedo Changes on Io", was published in ''Icarus'',<ref>{{cite journal |title=A Hubble Space Telescope Study of Posteclipse Brightening and Albedo Changes on Io |journal=Icarus |first1=James J. |last1=Secosky |first2=Michael |last2=Potter |volume=111 |issue=1 |pages=73–78 |date=September 1994 |doi=10.1006/icar.1994.1134 |bibcode=1994Icar..111...73S}}</ref> a journal devoted to solar system studies. A second study from another group of amateurs was also published in ''Icarus''.<ref>{{cite journal |url=http://scripts.mit.edu/~paleomag/articles/Storrs_1999_Icarus.pdf |title=Imaging Observations of Asteroids with Hubble Space Telescope |journal=Icarus |first1=Alex |last1=Storrs |first2=Ben |last2=Weiss |first3=Ben |last3=Zellner |first4=Win |last4=Burleson |first5=Rukmini |last5=Sichitiu |first6=Eddie |last6=Wells |first7=Charles |last7=Kowal |first8=David |last8=Tholen |display-authors=4 |volume=137 |issue=2 |pages=260–268 |date=February 1999 |doi=10.1006/icar.1999.6047 |bibcode=1999Icar..137..260S |url-status=dead |archive-url=https://web.archive.org/web/20120225134811/http://scripts.mit.edu/~paleomag/articles/Storrs_1999_Icarus.pdf |archive-date=February 25, 2012}}</ref> After that time, however, budget reductions at STScI made the support of work by amateur astronomers untenable, and no additional amateur programs have been carried out.<ref name="Omeara1997" /><ref name="motherboard20150424">{{cite news |last=Walthert |first=Matthew |date=April 24, 2015 |title=Open Mic Night at the Hubble Telescope |work=Motherboard |url=https://www.vice.com/en/article/open-mic-night-at-the-hubble-telescope/ |access-date=April 6, 2022 |archive-date=April 7, 2022 |archive-url=https://web.archive.org/web/20220407034408/https://www.vice.com/en/article/vvbnj3/open-mic-night-at-the-hubble-telescope |url-status=live }}</ref>

Regular Hubble proposals still include findings or discovered objects by amateurs and [[Citizen science|citizen scientists]]. These observations are often in a collaboration with professional astronomers. One of the earliest such observations is the [[Great White Spot]] of 1990<ref>{{Cite web|title=NASA's Hubble Space Telescope Views Major Storm On Saturn|url=http://hubblesite.org/contents/news-releases/1991/news-1991-04|access-date=October 22, 2020|website=HubbleSite.org|publisher=[[Space Telescope Science Institute]]|archive-date=July 15, 2022|archive-url=https://web.archive.org/web/20220715150146/https://hubblesite.org/contents/news-releases/1991/news-1991-04.html|url-status=live}}</ref> on planet Saturn, discovered by amateur astronomer S. Wilber<ref>{{Cite journal|last1=Wilber|first1=S.|last2=Tatum|first2=R.|last3=Kidger|first3=M.|last4=Gonzalez|first4=V.|last5=Hernandez|first5=F.|date=October 1, 1990|title=Saturn|url=http://adsabs.harvard.edu/abs/1990IAUC.5109....1W|journal=International Astronomical Union Circular|issue=5109|pages=1|bibcode=1990IAUC.5109....1W|access-date=October 22, 2020|archive-date=July 15, 2022|archive-url=https://web.archive.org/web/20220715150148/https://ui.adsabs.harvard.edu/abs/1990IAUC.5109....1W/abstract|url-status=live}}</ref> and observed by HST under a proposal by J. Westphal ([[California Institute of Technology|Caltech]]).<ref>{{Cite web|title=HST Proposal Search|url=https://archive.stsci.edu/proposal_search.php?id=3109&mission=hst|access-date=October 22, 2020|website=archive.stsci.edu|archive-date=July 15, 2022|archive-url=https://web.archive.org/web/20220715150221/https://archive.stsci.edu/proposal_search.php?id=3109&mission=hst|url-status=live}}</ref><ref>{{Cite web|title=HST Proposal Search|url=https://archive.stsci.edu/proposal_search.php?id=3090&mission=hst|access-date=October 22, 2020|website=archive.stsci.edu|archive-date=July 15, 2022|archive-url=https://web.archive.org/web/20220715150146/https://archive.stsci.edu/proposal_search.php?id=3090&mission=hst|url-status=live}}</ref> Later professional-amateur observations by Hubble include discoveries by the [[Galaxy Zoo]] project, such as [[Hanny's Voorwerp|Voorwerpjes]] and [[Pea galaxy|Green Pea galaxies]].<ref>{{Cite journal|last1=Keel|first1=William C.|last2=Maksym|first2=W. Peter|last3=Bennert|first3=Vardha N.|last4=Lintott|first4=Chris J.|last5=Chojnowski|first5=S. Drew|last6=Moiseev|first6=Alexei|last7=Smirnova|first7=Aleksandrina|last8=Schawinski|first8=Kevin|last9=Urry|first9=C. Megan|last10=Evans|first10=Daniel A.|last11=Pancoast|first11=Anna|date=May 1, 2015|title=HST Imaging of Fading AGN Candidates. I. Host-galaxy Properties and Origin of the Extended Gas|journal=The Astronomical Journal|volume=149|issue=5|pages=155|doi=10.1088/0004-6256/149/5/155|arxiv=1408.5159|bibcode=2015AJ....149..155K|doi-access=free}}</ref><ref>{{Cite journal|last1=Henry|first1=Alaina|last2=Scarlata|first2=Claudia|last3=Martin|first3=Crystal L.|last4=Erb|first4=Dawn|date=August 1, 2015|title=Lyalpha Emission from Green Peas: The Role of Circumgalactic Gas Density, Covering, and Kinematics|url=http://adsabs.harvard.edu/abs/2015ApJ...809...19H|journal=The Astrophysical Journal|volume=809|issue=1|pages=19|doi=10.1088/0004-637X/809/1/19|arxiv=1505.05149|bibcode=2015ApJ...809...19H|s2cid=119210958|access-date=October 22, 2020|archive-date=July 15, 2022|archive-url=https://web.archive.org/web/20220715150147/https://ui.adsabs.harvard.edu/abs/2015ApJ...809...19H/abstract|url-status=live}}</ref> The "Gems of the Galaxies" program is based on a list of objects by [[Galaxy Zoo]] volunteers that was shortened with the help of an online vote.<ref>{{Cite web|title=HST Proposal Search|url=https://archive.stsci.edu/proposal_search.php?id=15445&mission=hst|access-date=October 22, 2020|website=archive.stsci.edu|archive-date=July 15, 2022|archive-url=https://web.archive.org/web/20220715150146/https://archive.stsci.edu/proposal_search.php?id=15445&mission=hst|url-status=live}}</ref> Additionally there are observations of [[minor planet]]s discovered by amateur astronomers, such as [[2I/Borisov]] and changes in the atmosphere of the [[gas giant]]s Jupiter and Saturn or the [[ice giant]]s Uranus and Neptune.<ref>{{Cite web|title=Hubble Images Suggest Rogue Asteroid Smacked Jupiter|url=http://hubblesite.org/contents/news-releases/2010/news-2010-16|access-date=October 22, 2020|website=HubbleSite.org|publisher=[[Space Telescope Science Institute]]|archive-date=July 15, 2022|archive-url=https://web.archive.org/web/20220715150147/https://hubblesite.org/contents/news-releases/2010/news-2010-16.html|url-status=live}}</ref><ref>{{Cite web|title=Hubble Confirms New Dark Spot on Neptune|url=http://hubblesite.org/contents/news-releases/2016/news-2016-22|access-date=October 22, 2020|website=HubbleSite.org|publisher=[[Space Telescope Science Institute]]|archive-date=July 15, 2022|archive-url=https://web.archive.org/web/20220715150148/https://hubblesite.org/contents/news-releases/2016/news-2016-22.html|url-status=live}}</ref> In the pro-am collaboration [[Backyard Worlds|backyard worlds]] the HST was used to observe a [[Rogue planet|planetary mass object]], called [[WISE J0830+2837]]. The non-detection by the HST helped to classify this peculiar object.<ref>{{Cite journal|last1=Bardalez Gagliuffi|first1=Daniella C.|last2=Faherty|first2=Jacqueline K.|author2-link=Jackie Faherty|last3=Schneider|first3=Adam C.|last4=Meisner|first4=Aaron|last5=Caselden|first5=Dan|last6=Colin|first6=Guillaume|last7=Goodman|first7=Sam|last8=Kirkpatrick|first8=J. Davy|last9=Kuchner|first9=Marc|last10=Gagné|first10=Jonathan|last11=Logsdon|first11=Sarah E.|date=June 1, 2020|title=WISEA J083011.95+283716.0: A Missing Link Planetary-mass Object|journal=The Astrophysical Journal|volume=895|issue=2|pages=145|doi=10.3847/1538-4357/ab8d25|arxiv=2004.12829|bibcode=2020ApJ...895..145B|s2cid=216553879|doi-access=free }}</ref>