GOTO (telescope array)

{{short description|Array of robotic optical telescopes}} {{For|the type of computer-controlled telescope mounts|GoTo (telescopes)}} {{Infobox telescope | style = [[Newtonian telescope|Newtonian]] | first_light = {{start date|2017|06}} | area = 0.4m² per unit telescope, 3.2m² per system, 12.8m² total. | focal_length = 960mm (f/2.4) | image = [[File:GOTO-North Open.jpg|250px|alt=GOTO-N with both domes open.]] | caption = GOTO-N with both domes open. | mounting = Equatorial | website = [https://goto-observatory.org goto-observatory.org] }}

The '''Gravitational-wave Optical Transient Observer''' ('''GOTO''') is an array of robotic [[optical telescope]]s optimized for the discovery of [[Kilonova|optical counterparts]] to [[gravitational wave]] events<ref name="BBC">{{cite web |title=Neutron stars: New telescope detects dead suns colliding |url=https://www.bbc.co.uk/news/science-environment-61911047 |website=BBC News |access-date=24 January 2024 |date=21 July 2022}}</ref> and other [[Multi-messenger astronomy|multi-messenger]] signals. The array consists of a network of telescope systems, with each system consisting of eight 0.4m telescopes on a [[Telescope mount|single mounting]].<ref name=":2">{{cite book |last1=Dyer |first1=Martin J. |last2=Steeghs |first2=Danny |last3=Galloway |first3=Duncan K. |last4=Dhillon |first4=Vik S. |last5=O'Brien |first5=Paul |last6=Ramsay |first6=Gavin |last7=Noysena |first7=Kanthanakorn |last8=Pallé |first8=Enric |last9=Kotak |first9=Rubina |last10=Breton |first10=Rene |last11=Nuttall |first11=Laura |last12=Pollacco |first12=Don |last13=Ulaczyk |first13=Krzysztof |last14=Lyman |first14=Joseph |last15=Ackley |first15=Kendall D. |chapter=The Gravitational-wave Optical Transient Observer (GOTO) |editor-first1=Heather K. |editor-first2=Jason |editor-first3=Tomonori |editor-last1=Marshall |editor-last2=Spyromilio |editor-last3=Usuda |title=Ground-based and Airborne Telescopes VIII |date=13 December 2020 |volume=11445 |pages=1355–1362 |doi=10.1117/12.2561008 |chapter-url=https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11445/2561008/The-Gravitational-wave-Optical-Transient-Observer-GOTO/10.1117/12.2561008.short |ref=SPIE Paper |publisher=SPIE|arxiv=2012.02685 |bibcode=2020SPIE11445E..7GD |isbn=978-1-5106-3677-4 |s2cid=216906754 }}</ref>

As of May 2023 the network consists of two sites, each with two systems. GOTO-N (North) located at the [[Roque de los Muchachos Observatory]] (ORM) on the [[La Palma|island of La Palma]], [[Spain]]<ref name="IAC ORM">{{cite web |title=GOTO, a new robotic telescope for the Roque de los Muchachos Observatory |url=https://www.iac.es/en/outreach/news/goto-new-robotic-telescope-roque-de-los-muchachos-observatory |website=Instituto de Astrofísica de Canarias • IAC |access-date=24 January 2024 |language=en |date=3 July 2017}}</ref> and GOTO-S (South) located at [[Siding Spring Observatory]] (SSO), [[Australia]].<ref name="SidingSpring">{{cite web |last1=Yazgin |first1=Evrim |title=New telescopes in Australia to help find gravitational waves |url=https://cosmosmagazine.com/space/gravitational-waves-goto/ |website=cosmosmagazine.com |access-date=24 January 2024 |language=en-AU |date=7 July 2022}}</ref>

The project is run by an international consortium of universities and other research institutes, including the [[University of Warwick]], [[Monash University]], the [[University of Sheffield]], the [[University of Leicester]], [[Armagh Observatory]], the [[National Astronomical Research Institute of Thailand]], the [[Instituto de Astrofísica de Canarias]], the [[University of Portsmouth]], the [[University of Turku]], and the [[University of Birmingham]].<ref>{{Cite journal |last=Steeghs |first=Danny |date=2017-11-02 |title=Chasing light from the crest of a wave |url=https://www.nature.com/articles/s41550-017-0317-8 |journal=Nature Astronomy |language=en |volume=1 |issue=11 |pages=741 |doi=10.1038/s41550-017-0317-8 |bibcode=2017NatAs...1..741S |issn=2397-3366}}</ref>

== Design and operation ==

=== Telescopes === Each GOTO system can point independently, whilst each unit telescope (UT) has a fixed orientation on the [[Equatorial mount|mount]] so all 8 must be pointed at once. Each UT's pointing is offset from the others to cover the adjacent area of sky, with a small overlap between them. This results in each GOTO system acting as a single large telescope with a very wide [[field of view]] (FoV).<ref name=":2" />[[File:GOTO FoV.png|left|thumb|The [[Andromeda Galaxy]], with an overlay showing the field of view of a single GOTO unit telescope.]] [[File:GOTO Subgrid Array.svg|thumb|Relative positions of each unit telescope in a single GOTO system.]] The UTs are ASA H400 [[Newtonian telescope]]s, each with an aperture of 400mm and a focal length of 960mm (f/2.4).<ref name=":2" /> Attached to each telescope is a focuser, [[Photographic filter|filter wheel]], and a Finger Lakes Instrumentation (FLI) ML50100 camera,<ref name=":2" /> based on the [[Onsemi]] KAF-50100 CCD sensor.<ref>{{Cite web |title=New KAF-50100 sensor with microlenses |url=https://www.flicamera.com/51.php |access-date=2024-01-30 |website=www.flicamera.com}}</ref> The fast [[F-number|focal ratio]] of f/2.4 and large image sensor result in a relatively large field of view, with each GOTO system having a total FoV of approximately 40 [[Square degree|square degrees]],<ref name=":2" /> around 200x the area of the [[Full moon|full Moon]] in the sky. The fast focal ratio also means that only a small amount of time is needed to observe each area of the sky, with each visit requiring only 3 minutes of [[exposure time]].<ref name=":2" /> === Identifying transients === GOTO utilises [[Image subtraction|difference imaging]] to identify changes of existing objects and the appearance of new objects (known as astronomical transients).<ref name=":0" /> Images of the sky are matched to previous observations of the same region, finding the difference between these two images will show only the changes in the new image. Sources within these difference images can then be detected automatically. Using difference imaging in this way produces many thousands of candidate sources per image, the vast majority of which are [[Artifact (error)|artefacts]] of the processing and not real transients.<ref>{{Cite journal |last1=Brink |first1=Henrik |last2=Richards |first2=Joseph W. |last3=Poznanski |first3=Dovi |last4=Bloom |first4=Joshua S. |last5=Rice |first5=John |last6=Negahban |first6=Sahand |last7=Wainwright |first7=Martin |date=2013-10-21 |title=Using machine learning for discovery in synoptic survey imaging data |url=http://academic.oup.com/mnras/article/435/2/1047/1033222/Using-machine-learning-for-discovery-in-synoptic |journal=Monthly Notices of the Royal Astronomical Society |language=en |volume=435 |issue=2 |pages=1047–1060 |doi=10.1093/mnras/stt1306 |doi-access=free |issn=1365-2966|arxiv=1209.3775 }}</ref><ref name=":1" /> GOTO utilises a [[convolutional neural network]] based 'real-bogus' classifier to identify which sources are likely to be real.<ref name=":1">{{Cite journal |last1=Killestein |first1=T L |last2=Lyman |first2=J |last3=Steeghs |first3=D |last4=Ackley |first4=K |last5=Dyer |first5=M J |last6=Ulaczyk |first6=K |last7=Cutter |first7=R |last8=Mong |first8=Y-L |last9=Galloway |first9=D K |last10=Dhillon |first10=V |last11=O'Brien |first11=P |last12=Ramsay |first12=G |last13=Poshyachinda |first13=S |last14=Kotak |first14=R |last15=Breton |first15=R P |date=2021-04-09 |title=Transient-optimized real-bogus classification with Bayesian convolutional neural networks – sifting the GOTO candidate stream |url=https://academic.oup.com/mnras/article/503/4/4838/6171008 |journal=Monthly Notices of the Royal Astronomical Society |language=en |volume=503 |issue=4 |pages=4838–4854 |doi=10.1093/mnras/stab633 |doi-access=free |issn=0035-8711|arxiv=2102.09892 }}</ref>

=== Gamma-ray bursts === In addition to follow-up of gravitational wave events, GOTO can respond to detections of [[gamma-ray burst|gamma-ray bursts (GRBs)]].<ref>{{Cite journal |last1=Mong |first1=Y-L |last2=Ackley |first2=K |last3=Galloway |first3=D K |last4=Dyer |first4=M |last5=Cutter |first5=R |last6=Brown |first6=M J I |last7=Lyman |first7=J |last8=Ulaczyk |first8=K |last9=Steeghs |first9=D |last10=Dhillon |first10=V |last11=O’Brien |first11=P |last12=Ramsay |first12=G |last13=Noysena |first13=K |last14=Kotak |first14=R |last15=Breton |first15=R |date=2021-09-07 |title=Searching for ''Fermi'' GRB optical counterparts with the prototype Gravitational-wave Optical Transient Observer (GOTO) |journal=Monthly Notices of the Royal Astronomical Society |volume=507 |issue=4 |pages=5463–5476 |doi=10.1093/mnras/stab2499 |doi-access=free |issn=0035-8711|arxiv=2108.11802 }}</ref> On September 11, 2023, the [[Fermi Gamma-ray Space Telescope]] detected a gamma ray burst (GRB 230911A)<ref>{{Cite web |title=GCN - Circulars - 34652 - GRB 230911A: Fermi GBM Final Real-time Localization |url=https://gcn.nasa.gov/circulars/34652 |access-date=2024-08-21 |website=gcn.nasa.gov}}</ref> and follow-up observations by GOTO discovered an optical counterpart (GOTO23akf/AT 2023shv),<ref>{{Cite web |title=AT 2023shv {{!}} Transient Name Server |url=https://www.wis-tns.org/object/2023shv |access-date=2024-08-21 |website=www.wis-tns.org}}</ref> which was later confirmed as a [[Gamma-ray burst#Afterglow|GRB afterglow]] by the [[Neil Gehrels Swift Observatory|Swift X-ray telescope]].<ref>{{Cite journal |last1=Belkin |first1=S. |last2=Gompertz |first2=B. P. |last3=Kumar |first3=A. |last4=Ackley |first4=K. |last5=Galloway |first5=D. K. |last6=Jiménez-Ibarra |first6=F. |last7=Killestein |first7=T. L. |last8=O’Neill |first8=D. |last9=Wiersema |first9=K. |last10=Malesani |first10=D. B. |last11=Levan |first11=A. J. |last12=Lyman |first12=J. |last13=Dyer |first13=M. J. |last14=Ulaczyk |first14=K. |last15=Steeghs |first15=D. |date=2024-01-04 |title=GRB 230911A: The First Discovery of a Fermi GRB Optical Counterpart with the Gravitational-wave Optical Transient Observer (GOTO) |journal=Research Notes of the AAS |volume=8 |issue=1 |pages=6 |doi=10.3847/2515-5172/ad1876 |doi-access=free |bibcode=2024RNAAS...8....6B |issn=2515-5172}}</ref>

In 2024, GOTO discovered the optical counterpart of seven gamma-ray bursts, which were the subject of continued observations by both GOTO and other telescopes, including the [[Very Large Telescope]] and [[Gran Telescopio Canarias]].<ref>{{Cite journal |last1=Kumar |first1=Amit |last2=Gompertz |first2=B P |last3=Schneider |first3=B |last4=Belkin |first4=S |last5=Wortley |first5=M E |last6=Saccardi |first6=A |last7=O’Neill |first7=D |last8=Ackley |first8=K |last9=Rayson |first9=B |last10=Postigo |first10=A de Ugarte |last11=Gulati |first11=A |last12=Steeghs |first12=D |last13=Malesani |first13=D B |last14=Maund |first14=J R |last15=Dyer |first15=M J |date=2025-11-08 |title=Discovery and analysis of afterglows from poorly localized GRBs with the Gravitational-wave Optical Transient Observer (GOTO) All-sky Survey |url=https://academic.oup.com/mnras/article/544/2/1541/8272723 |journal=Monthly Notices of the Royal Astronomical Society |language=en |volume=544 |issue=2 |pages=1541–1587 |doi=10.1093/mnras/staf1689 |doi-access=free |issn=0035-8711|hdl=10261/430226 |hdl-access=free }}</ref>

=== All-sky survey === {{Location map+|World|places={{Location map~ | World | label = GOTO-N | coordinates = {{coord|28|45|36.36|N|17|52|45.54|W|}}}} {{Location map~ | World | label = GOTO-S | coordinates = {{coord|31|16|24.28|S|149|3|50.83|E|}}}}|caption=Locations of GOTO-N and GOTO-S.|width=300|alt=location of GOTO-N in La Palma off the coast of Morocco and GOTO-S in eastern Australia|float=right}}GOTO's typical mode of operation when not performing a follow-up campaign is to survey the entire visible sky. As there are sites located in both the northern and southern hemispheres, the visible sky for GOTO is all areas which are visible at night from anywhere on the Earth. If both sites have good weather conditions the entire visible sky can be observed every 2–3 days.<ref name=":2" />

These observations are processed using difference imaging which allows for [[Serendipity|serendipitous]] discovery of transients unrelated to multi-messenger events, like [[supernova]]e, [[tidal disruption event]]s, and [[fast blue optical transient]]s.<ref name=":0" />

== History == {{Multiple image | image1 = GOTO discovery count total 2026.png | image2 = GOTO discovery count monthly up to 2026.png | caption1 = Total | caption2 = Monthly | caption_align = center | footer = Total (line) and monthly (bar) count of transients discovered by GOTO between 2020 and January 7 2026. | align = left | total_width = | direction = vertical }} The first phase of GOTO's development was the deployment of a prototype system located at the planned site of the northern node, consisting of four unit telescopes on a custom-built mount.<ref name=":0">{{cite journal |last1=Steeghs |first1=D |last2=Galloway |first2=D K |last3=Ackley |first3=K |last4=Dyer |first4=M J |last5=Lyman |first5=J |last6=Ulaczyk |first6=K |last7=Cutter |first7=R |last8=Mong |first8=Y-L |last9=Dhillon |first9=V |last10=O'Brien |first10=P |last11=Ramsay |first11=G |last12=Poshyachinda |first12=S |last13=Kotak |first13=R |last14=Nuttall |first14=L K |last15=Pallé |first15=E |last16=Breton |first16=R P |last17=Pollacco |first17=D |last18=Thrane |first18=E |last19=Aukkaravittayapun |first19=S |last20=Awiphan |first20=S |last21=Burhanudin |first21=U |last22=Chote |first22=P |last23=Chrimes |first23=A |last24=Daw |first24=E |last25=Duffy |first25=C |last26=Eyles-Ferris |first26=R |last27=Gompertz |first27=B |last28=Heikkilä |first28=T |last29=Irawati |first29=P |last30=Kennedy |first30=M R |last31=Killestein |first31=T |last32=Kuncarayakti |first32=H |last33=Levan |first33=A J |last34=Littlefair |first34=S |last35=Makrygianni |first35=L |last36=Marsh |first36=T |last37=Mata-Sanchez |first37=D |last38=Mattila |first38=S |last39=Maund |first39=J |last40=McCormac |first40=J |last41=Mkrtichian |first41=D |last42=Mullaney |first42=J |last43=Noysena |first43=K |last44=Patel |first44=M |last45=Rol |first45=E |last46=Sawangwit |first46=U |last47=Stanway |first47=E R |last48=Starling |first48=R |last49=Strøm |first49=P |last50=Tooke |first50=S |last51=West |first51=R |last52=White |first52=D J |last53=Wiersema |first53=K |title=The Gravitational-wave Optical Transient Observer (GOTO): prototype performance and prospects for transient science |journal=Monthly Notices of the Royal Astronomical Society |date=April 2022 |volume=511 |issue=2 |pages=2405–2422 |doi=10.1093/mnras/stac013 |doi-access=free |ref=Prototype Paper|arxiv=2110.05539 }}</ref> The prototype system was deployed during the second [[LIGO]]-[[Virgo interferometer|Virgo]] Collaboration (LVC) observing run (O2), achieving first light in June 2017<ref name=":0" /> with its official inauguration on July 3, 2017.<ref name="IAC ORM" />

The prototype system was active during the first half of the third LVC observing run (O3a), which ran between April and October 2019.<ref>{{Cite journal |last1=Abbott |first1=R. |last2=Abe |first2=H. |last3=Acernese |first3=F. |last4=Ackley |first4=K. |last5=Adhicary |first5=S. |last6=Adhikari |first6=N. |last7=Adhikari |first7=R. X. |last8=Adkins |first8=V. K. |last9=Adya |first9=V. B. |last10=Affeldt |first10=C. |last11=Agarwal |first11=D. |last12=Agathos |first12=M. |last13=Aguiar |first13=O. D. |last14=Aiello |first14=L. |last15=Ain |first15=A. |date=2023-08-01 |title=Open Data from the Third Observing Run of LIGO, Virgo, KAGRA, and GEO |journal=The Astrophysical Journal Supplement Series |volume=267 |issue=2 |pages=29 |doi=10.3847/1538-4365/acdc9f |doi-access=free |issn=0067-0049|arxiv=2302.03676 |bibcode=2023ApJS..267...29A }}</ref> During this time GOTO was able to respond to gravitational-wave events and begin observing within one minute of alerts being received (if the source region was visible).<ref>{{Cite journal |last1=Gompertz |first1=B P |last2=Cutter |first2=R |last3=Steeghs |first3=D |last4=Galloway |first4=D K |last5=Lyman |first5=J |last6=Ulaczyk |first6=K |last7=Dyer |first7=M J |last8=Ackley |first8=K |last9=Dhillon |first9=V S |last10=O’Brien |first10=P T |last11=Ramsay |first11=G |last12=Poshyachinda |first12=S |last13=Kotak |first13=R |last14=Nuttall |first14=L |last15=Breton |first15=R P |date=2020-09-01 |title=Searching for electromagnetic counterparts to gravitational-wave merger events with the prototype Gravitational-Wave Optical Transient Observer (GOTO-4) |url=https://academic.oup.com/mnras/article/497/1/726/5866841 |journal=Monthly Notices of the Royal Astronomical Society |language=en |volume=497 |issue=1 |pages=726–738 |doi=10.1093/mnras/staa1845 |doi-access=free |issn=0035-8711|arxiv=2004.00025 }}</ref>

In late 2019 funding was awarded to expand the network with two full GOTO systems a duplicate site in Australia.<ref>{{Cite web |date=2020-04-05 |title=Funding Approved For GOTO Expansion |url=https://goto-observatory.org/funding-approved-for-goto-expansion/ |access-date=2024-01-25 |website=GOTO Observatory}}</ref> In 2020 the first full system of the northern node was being deployed, with the second system planned for early 2021 and the Australian site planned for later that year.<ref>{{Cite book |last1=Dyer |first1=Martin J. |last2=Steeghs |first2=Danny |last3=Galloway |first3=Duncan K. |last4=Dhillon |first4=Vik S. |last5=O'Brien |first5=Paul |last6=Ramsay |first6=Gavin |last7=Noysena |first7=Kanthanakorn |last8=Pallé |first8=Enric |last9=Kotak |first9=Rubina |last10=Breton |first10=Rene |last11=Nuttall |first11=Laura |last12=Pollacco |first12=Don |last13=Ulaczyk |first13=Krzysztof |last14=Lyman |first14=Joseph |last15=Ackley |first15=Kendall D. |chapter=The Gravitational-wave Optical Transient Observer (GOTO) |editor-first1=Heather K. |editor-first2=Jason |editor-first3=Tomonori |editor-last1=Marshall |editor-last2=Spyromilio |editor-last3=Usuda |date=2020-12-13 |title=Ground-based and Airborne Telescopes VIII |chapter-url=https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11445/114457G/The-Gravitational-wave-Optical-Transient-Observer-GOTO/10.1117/12.2561008.full |publisher=SPIE |volume=11445 |pages=1355–1362 |doi=10.1117/12.2561008|arxiv=2012.02685 |bibcode=2020SPIE11445E..7GD |isbn=978-1-5106-3677-4 |s2cid=216906754 |url=https://wrap.warwick.ac.uk/170742/1/WRAP-The-Gravitational-wave-Optical-Transient-Observer-GOTO-2022.pdf }}</ref>

The deployment of the second northern system was completed in August 2021<ref>{{Cite web |last=Ulaczyk |first=Krzysztof |date=2021-08-01 |title=Second GOTO system installed at Roque de Los Muchachos Observatory |url=https://goto-observatory.org/second-goto-system-installed-at-roque-de-los-muchachos-observatory/ |access-date=2024-01-25 |website=goto-observatory.org}}</ref> and, despite delays due to the [[2021 Cumbre Vieja volcanic eruption|2021 volcanic eruption]], the full northern node was completed in December 2021 with the upgrade of the prototype to the final hardware configuration.<ref>{{Cite web |last=Ulaczyk |first=Krzysztof |date=2021-12-08 |title=Full northern node deployed! |url=https://goto-observatory.org/full-northern-node-deployed/ |access-date=2024-01-25 |website=goto-observatory.org}}</ref>

By the end of 2022 the site for the second GOTO node (GOTO-S) had been prepared at Siding Spring Observatory (SSO) and the two domes installed.<ref>{{Cite web |last= |date=2024-01-29 |title=GOTO-South |url=https://rsaa.anu.edu.au/about/observatories/telescopes/goto-south |access-date=2024-01-29 |publisher=Australian National University |language=en}}</ref><ref>{{Cite web |last=Ulaczyk |first=Krzysztof |date=2022-12-08 |title=New GOTO domes erected in Siding Spring Observatory |url=https://goto-observatory.org/new-goto-domes-erected-in-siding-spring-observatory/ |access-date=2024-01-25 |website=goto-observatory.org}}</ref> In May 2023 it was announced that both systems at SSO had been successfully installed.<ref>{{Cite web |last=Ulaczyk |first=Krzysztof |date=2023-05-08 |title=Two new arrays of telescopes installed at Siding Spring Observatory |url=https://goto-observatory.org/two-new-arrays-of-telescopes-installed-at-siding-spring-observatory/ |access-date=2024-01-26 |website=goto-observatory.org}}</ref>

== Discoveries == As of January 7, 2026, data from GOTO has been used in the discovery of 4,288 astronomical transients, of which 543 have been classified as supernovae and four as tidal disruption events.<ref>{{cite web |title=TNS Transients Statistics, Skymaps and Plots {{!}} Transient Name Server |url=https://www.wis-tns.org/stats-maps |url-status=live |archive-url=https://web.archive.org/web/20260107112933/https://www.wis-tns.org/stats-maps |archive-date=7 January 2026 |access-date=7 January 2026 |website=www.wis-tns.org |publisher=International Astronomical Union |ref=IAU Statistics}}</ref><ref>{{Cite web |title=AT 2023lli {{!}} Transient Name Server |url=https://www.wis-tns.org/object/2023lli |url-status=live |archive-url=https://web.archive.org/web/20240203002828/https://www.wis-tns.org/object/2023lli |archive-date=2024-02-03 |access-date=2024-02-03 |website=www.wis-tns.org}}</ref><ref>{{Cite web |title=2024aegq {{!}} Transient Name Server |url=https://www.wis-tns.org/object/2024aegq |access-date=2025-01-29 |website=www.wis-tns.org}}</ref> [[File:Annotated Image of Supernova 2025rbs.png|alt=Supernova 2025rbs within the spiral galaxy NGC 7331|thumb|An image of SN 2025rbs, a Type Ia supernova discovered by GOTO]] SN 2025rbs in the galaxy [[NGC 7331#Supernovae|NGC 7331]] was discovered by GOTO on July 14, 2025.<ref>{{Cite web |title=2025rbs {{!}} Transient Name Server |url=https://www.wis-tns.org/object/2025rbs |access-date=2025-07-31 |website=www.wis-tns.org}}</ref> Within a day of discovery it was classified based on its [[Astronomical spectroscopy|optical spectrum]] as a [[Type Ia supernova]].<ref>{{Cite web |title=Classification certificate for object 2025rbs {{!}} Transient Name Server |url=https://www.wis-tns.org/object/2025rbs/classification-cert |access-date=2025-07-31 |website=www.wis-tns.org}}</ref> Later that month it reached a peak brightness of around [[Magnitude (astronomy)|magnitude]] 12,<ref>{{Cite web |title=Supernova 2025rbs in NGC 7331 |url=https://www.rochesterastronomy.org/sn2025/sn2025rbs.html |access-date=2025-09-25 |website=www.rochesterastronomy.org}}</ref> easily visible in [[Amateur astronomy|amateur telescopes]].

=== The First Gravitationally Lensed Superluminous Supernova === SN 2025wny was discovered and reported by GOTO on September 1, 2025.<ref>{{Cite web |title=Discovery certificate for object 2025wny {{!}} Transient Name Server |url=https://www.wis-tns.org/object/2025wny/discovery-cert |access-date=2026-01-08 |website=www.wis-tns.org}}</ref><ref>{{Cite web |title=2025wny {{!}} Transient Name Server |url=https://www.wis-tns.org/object/2025wny |access-date=2026-01-08 |website=www.wis-tns.org}}</ref> It was quickly identified as a candidate [[Gravitational lens|gravitationally lensed]] supernova,<ref name=":3">{{Cite journal |last1=Johansson |first1=Joel |last2=Perley |first2=Daniel A. |last3=Goobar |first3=Ariel |last4=Wise |first4=Jacob L. |last5=Qin |first5=Yu-Jing |last6=McGrath |first6=Zoë |last7=Schulze |first7=Steve |last8=Lemon |first8=Cameron |last9=Gangopadhyay |first9=Anjasha |last10=Tsalapatas |first10=Konstantinos |last11=Andreoni |first11=Igor |last12=Bellm |first12=Eric C. |last13=Bloom |first13=Joshua S. |last14=Dekany |first14=Richard |last15=Dhawan |first15=Suhail |date=2025-12-05 |title=Discovery of SN 2025wny: A Strongly Gravitationally Lensed Superluminous Supernova at ''z''= 2.01 |journal=The Astrophysical Journal Letters |volume=995 |issue=1 |pages=L17 |doi=10.3847/2041-8213/ae1d61 |doi-access=free |arxiv=2510.23533 |bibcode=2025ApJ...995L..17J |issn=2041-8205}}</ref> where the gravitational effect of a massive object like a galaxy causes the light from the supernova to be bent and magnified.

Spectroscopic observations from the [[Nordic Optical Telescope]] and [[W. M. Keck Observatory]] confirmed that the light from 2025wny was being gravitationally lensed and also showed it was a [[superluminous supernova]] (SLSN),<ref name=":3" /> making it the first example of a gravitationally lensed SLSN.<ref>{{Cite web |date=2025-12-12 |title=Astronomers Discover the First Gravitationally Lensed Superluminous Supernova – W. M. Keck Observatory |url=https://keckobservatory.org/sn-2025wny/ |access-date=2026-01-08 |language=en-US}}</ref> Images taken later that month by the [[Liverpool Telescope]] showed multiple images of the supernova in an [[Einstein Cross]] pattern.<ref>{{Cite web |title=2025-296 {{!}} Transient Name Server |url=https://www.wis-tns.org/astronotes/astronote/2025-296 |access-date=2026-01-08 |website=www.wis-tns.org}}</ref>

=== Superluminous Supernova Driven by a Magnetar === In late 2024, the supernova SN 2024afav was discovered by GOTO and classified as a superluminous supernova.<ref>{{Cite web |title=Discovery certificate for object 2024afav {{!}} Transient Name Server |url=https://www.wis-tns.org/object/2024afav/discovery-cert |access-date=2026-03-14 |website=www.wis-tns.org}}</ref><ref>{{Cite web |title=Classification certificate for object 2024afav {{!}} Transient Name Server |url=https://www.wis-tns.org/object/2024afav/classification-cert |access-date=2026-03-14 |website=www.wis-tns.org}}</ref> Observations of 2024afav by the [[Las Cumbres Observatory]] network showed it varied in brightness, with bumps in its [[light curve]].<ref>{{Cite journal |last=Kumar |first=Harsh |last2=Blanchard |first2=Peter K. |last3=Berger |first3=Edo |last4=Athukoralalage |first4=Wasundara |last5=Hiramatsu |first5=Daichi |last6=Gomez |first6=Sebastian |last7=Andrews |first7=Moira |last8=Bostroem |first8=K. Azalee |last9=Farah |first9=Joseph R. |last10=Howell |first10=D. Andrew |last11=McCully |first11=Curtis |date=2026-02-02 |title=SN 2024afav: A Superluminous Supernova with Multiple Light-curve Bumps and Spectroscopic Signatures of Circumstellar Interaction |url=https://iopscience.iop.org/article/10.3847/2041-8213/ae3749 |journal=The Astrophysical Journal Letters |volume=998 |issue=1 |pages=L3 |doi=10.3847/2041-8213/ae3749 |doi-access=free|issn=2041-8205}}</ref> In 2026, a paper was published in the journal [[Nature (journal)|Nature]], showing that the way in which the period of these bumps changed over time could be explained by a newly formed [[magnetar]], a highly magnetic neutron star, providing energy to power the supernova.<ref>{{Cite journal |last=Farah |first=Joseph R. |last2=Prust |first2=Logan J. |last3=Howell |first3=D. Andrew |last4=Ni |first4=Yuan Qi |last5=McCully |first5=Curtis |last6=Andrews |first6=Moira |last7=Kumar |first7=Harsh |last8=Hiramatsu |first8=Daichi |last9=Gomez |first9=Sebastian |last10=Wynn |first10=Kathryn |last11=Filippenko |first11=Alexei V. |last12=Bostroem |first12=K. Azalee |last13=Berger |first13=Edo |last14=Blanchard |first14=Peter |date=2026-03-11 |title=Lense–Thirring precessing magnetar engine drives a superluminous supernova |url=https://www.nature.com/articles/s41586-026-10151-0 |journal=Nature |language=en |volume=651 |issue=8105 |pages=321–325 |doi=10.1038/s41586-026-10151-0 |issn=1476-4687|url-access=subscription }}</ref><ref>{{Cite web |last=Young |first=Monica |date=2026-03-11 |title=Super-Bright Supernovae Are Magnetar Birth Cries |url=https://skyandtelescope.org/astronomy-news/super-bright-supernovae-are-magnetar-birth-cries/ |access-date=2026-03-14 |website=Sky & Telescope |language=en-US}}</ref>

== Kilonova Seekers == Kilonova Seekers is a [[citizen science]] project on the [[Zooniverse]] platform designed to assist GOTO in identifying real astrophysical transients.<ref>{{Cite web |date=2023-07-12 |title=Play 'spot the difference' to help scientists identify cosmic explosions |url=https://www.port.ac.uk/news-events-and-blogs/news/play-spot-the-difference-to-help-scientists-identify-cosmic-explosions |access-date=2025-01-31 |website=University of Portsmouth |language=en}}</ref> Volunteers are shown transient detections from GOTO, alongside a reference GOTO observation and the difference between the two, and asked whether they believe it to be a real detection. If a source reaches an 80% consensus, and has at least 8 votes, an alert is sent to the GOTO team for further investigation.<ref>{{Cite journal |last1=Killestein |first1=T L |last2=Kelsey |first2=L |last3=Wickens |first3=E |last4=Nuttall |first4=L |last5=Lyman |first5=J |last6=Krawczyk |first6=C |last7=Ackley |first7=K |last8=Dyer |first8=M J |last9=Jiménez-Ibarra |first9=F |last10=Ulaczyk |first10=K |last11=O’Neill |first11=D |last12=Kumar |first12=A |last13=Steeghs |first13=D |last14=Galloway |first14=D K |last15=Dhillon |first15=V S |date=2024-09-11 |title=Kilonova Seekers: the GOTO project for real-time citizen science in time-domain astrophysics |url=https://academic.oup.com/mnras/article/533/2/2113/7735340 |journal=Monthly Notices of the Royal Astronomical Society |volume=533 |issue=2 |pages=2113–2132 |doi=10.1093/mnras/stae1817 |doi-access=free |issn=0035-8711|hdl=2299/28414 |hdl-access=free }}</ref>

As of January 31, 2025, there have been over 2 million classifications made via Kilonova Seekers by over 3200 volunteers. In total over 158,000 possible sources have been completed as either real or bogus.<ref>{{Cite web |title=Kilonova Seekers |url=https://www.zooniverse.org/projects/tkillestein/kilonova-seekers |access-date=2025-01-31 |website=[[Zooniverse]]}}</ref>

== See also ==

* [[All Sky Automated Survey for SuperNovae|All Sky Automated Survey for SuperNovae (ASAS-SN)]] * [[Asteroid Terrestrial-impact Last Alert System|Asteroid Terrestrial-impact Last Alert System (ATLAS)]] * [[BlackGEM]] * [[Pan-STARRS]] * [[Vera C. Rubin Observatory]] * [[Zwicky Transient Facility|Zwicky Transient Facility (ZTF)]]

== References ==

{{reflist}}{{Portal bar|Astronomy|Stars}}{{Astronomy navbox}} [[Category:Astronomical surveys]] [[Category:Optical telescopes]] [[Category:Robotic telescopes]] [[Category:Astronomical observatories in La Palma]] [[Category:Siding Spring Observatory]]