{{Short description|Global network of identical telescopes}} {{Infobox telescope | name = Global Oscillation Network Group (GONG) | image = 250px|alt=GONG network sites map | caption = Map of GONG stations | organization = National Solar Observatory Integrated Synoptic Program (NISP) | location = | coords = see {{slink||Sites}} | built = 1995 | website = {{URL|https://gong.nso.edu}} }}
The '''Global Oscillation Network Group''' (GONG) is a worldwide network of six identical telescopes, designed to have 24/7 observations of the Sun.<ref>{{cite journal |last1=Harvey |first1=J. W. |last2=Hill |first2=F. |last3=Hubbard |first3=R. P. |last4=Kennedy |first4=J. R. |last5=Leibacher |first5=J. W. |last6=Pintar |first6=J. A. |last7=Gilman |first7=P. A. |last8=Noyes |first8=R. W. |last9=Title |first9=A. M. |last10=Toomre |first10=J. |last11=Ulrich |first11=R. K. |last12=Bhatnagar |first12=A. |last13=Kennewell |first13=J. A. |last14=Marquette |first14=W. |last15=Patrón |first15=J. |last16=Saá |first16=O. |last17=Yasukawa |first17=E. |title=The Global Oscillation Network Group (GONG) Project |journal=Science |date=31 May 1996 |volume=272 |issue=5266 |pages=1284–1286 |doi=10.1126/science.272.5266.1284|pmid=8662455 |bibcode=1996Sci...272.1284H }}</ref><ref>{{Cite journal |last=Jain |first=Kiran |last2=Harvey |first2=John W. |last3=Hill |first3=Frank |last4=Komm |first4=Rudolf W. |last5=Leibacher |first5=John W. |last6=Petrie |first6=Gordon J. D. |last7=Pevtsov |first7=Alexei A. |last8=Tripathy |first8=Sushanta C. |date=2026-04-07 |title=Three Decades of Global Oscillation Network Group (GONG): From Helioseismology to Magnetic Field and Space Weather (Invited Review) |url=https://doi.org/10.1007/s11207-026-02639-9 |journal=Solar Physics |language=en |volume=301 |issue=4 |pages=50 |doi=10.1007/s11207-026-02639-9 |issn=1573-093X|doi-access=free }}</ref> The network serves multiple purposes, including the provision of operation data for use in space weather prediction,<ref>{{cite journal |last1=Hill |first1=Frank |title=The Global Oscillation Network Group Facility—An Example of Research to Operations in Space Weather |journal=Space Weather |date=October 2018 |volume=16 |issue=10 |pages=1488–1497 |doi=10.1029/2018SW002001|bibcode=2018SpWea..16.1488H |doi-access=free }}</ref> and the study of solar internal structure and dynamics using helioseismology.
Deployed in 1995, GONG is a set of six observing systems geographically distributed around the Earth so that the Sun can be observed as continuously as possible. The six observatories are the Teide Observatory (Canary Islands), the [https://www.sws.bom.gov.au/Solar/3/1 Learmonth Solar Observatory] (Western Australia), the Big Bear Solar Observatory (California), the Mauna Loa Observatory (Hawaii), the Udaipur Solar Observatory (India) and the Cerro Tololo Inter-American Observatory (Chile). With these sites, GONG typically can observe the Sun 91% of the time, 24/7.<ref>{{Cite journal |last1=Jain |first1=Kiran |last2=Tripathy |first2=Sushanta C. |last3=Hill |first3=Frank |last4=Pevtsov |first4=Alexei A. |date=2021-10-01 |title=Continuous Solar Observations from the Ground—Assessing Duty Cycle from GONG Observations |url=https://iopscience.iop.org/article/10.1088/1538-3873/ac24d5 |journal=Publications of the Astronomical Society of the Pacific |volume=133 |issue=1028 |pages=105001 |doi=10.1088/1538-3873/ac24d5 |arxiv=2110.06319 |bibcode=2021PASP..133j5001J |s2cid=238362018 |issn=0004-6280}}</ref> GONG was constructed to provide observations for helioseismology, which aims to understand the solar interior by analyzing the sound waves that are trapped in it. In 2001, the original GONG detectors were upgraded to 1000 x 1000 pixels and continuous magnetograms were implemented, and the new system is known as GONG++. While GONG still provides helioseismology data, it now also provides full-disk solar magnetic field maps (magnetograms) every minute and full-disk images of the Sun in the wavelength of the Hydrogen–α (Hα) spectral line every 20 seconds. These [https://gong2.nso.edu/products/mainView/table.php?configFile=configs/mainView.cfg data products] are used for research into the solar magnetic field and chromosphere but are also essential inputs into forecasts of space weather. The NOAA Space Weather Prediction Center (SWPC), the US Airforce 557th Weather Wing, and the NASA Community Coordinated Modeling Center (CCMC) all use GONG data to predict space weather conditions. GONG magnetograms are used in modeling of magnetic connectivity between the photosphere and the solar wind in support of NASA's Parker Solar Probe mission.
The GONG Project is managed by the National Solar Observatory (NSO) Integrated Synoptic Program (NISP), which is operated by the Association of Universities for Research in Astronomy under a cooperative agreement with the National Science Foundation (NSF). GONG has been in operation since 1995 and is aging rapidly. To replace it, NSO is proposing to design and build a next-generation Ground-based solar Observing Network, provisionally named ngGONG.<ref>{{Cite arXiv |last1=Pevtsov |first1=Alexei A. |last2=Martinez-Pillet |first2=V. |last3=Gilbert |first3=H. |last4=de Wijn |first4=A. G. |last5=Roth |first5=M. |last6=Gosain |first6=S. |last7=Upton |first7=L. A. |last8=Katsukawa |first8=Y. |last9=Burkepile |first9=J. |last10=Zhang |first10=Jie |last11=Reardon |first11=K. P. |last12=Bertello |first12=L. |last13=Jain |first13=K. |last14=Tripathy |first14=S. C. |last15=Leka |first15=K. D. |date=2022-11-12 |title= Helio2024 Science White Paper: ngGONG -- Future Ground-based Facilities for Research in Heliophysics and Space Weather Operational Forecast|class=astro-ph.IM |eprint=2211.06712}}</ref> In April 2023, [https://sab.noaa.gov/ NOAA Science Advisory Board] reported on the importance of GONG and its successor data source for space weather operations.<ref>{{Cite web |date=27 April 2023 |title=Statement on Global Oscillation Network Group (GONG) and its Successor Data Source for Space Weather Operations |url=https://sab.noaa.gov/wp-content/uploads/SAB_Report_Apr2023_Space-Weather_GONG.pdf |access-date=12 May 2024 |website=NOAA Science Advisory Board Reports, Report Library}}</ref> It concluded that "GONG provides a vital data source for space weather operations, and it is nearing end of life. The ngGONG project is the most straightforward replacement. It will maintain present operational capabilities, and provide observations for future requirements. The time window to complete ngGONG prior to the demise of GONG is closing." The Board recommended that "NOAA/NWS financially support the design phase for ngGONG, to ensure the initiation of the project."
The Decadal Survey for Solar and Space Physics (Heliophysics) 2024–2033 by the National Academies of Sciences, Engineering, and Medicine<ref>{{Cite book |author1=((Committee on a Decadal Survey for Solar and Space Physics (Heliophysics) 2024–2033)) |url=https://nap.nationalacademies.org/catalog/27938 |title=The Next Decade of Discovery in Solar and Space Physics: Exploring and Safeguarding Humanity's Home in Space |author2=((Space Studies Board)) |author3=((Division on Engineering and Physical Sciences)) |author4=((National Academies of Sciences, Engineering, and Medicine)) |date=2024 |publisher=National Academies Press |isbn=978-0-309-72555-2 |location=Washington, D.C. |doi=10.17226/27938 |bibcode=2024ndds.book.....N }}</ref> recommends ngGONG as NSF's top priority for its Major Research Equipment and Facilities Construction (MREFC) Program.
==Sites== The six GONG stations are located at the geographic coordinates and elevations given in the following table.<ref>{{cite web |title=The Latitude, Longitude and Elevation of the GONG Network of Sites |url=https://gong.nso.edu/sites/lat_long_elv.html |website=NSO/GONG |access-date=28 December 2024}}</ref> {{table alignment}} {| class="wikitable sortable col1left" style=text-align:right |+ Geographical coordinates and elevations of the GONG stations |- ! Observatory ! data-sort-type=number | Latitude ! data-sort-type=number | Longitude ! data-sort-type=number | Elevation |- | Mauna Loa Observatory | 19° 32′ 10.1″ N | data-sort-value=-155 | 155° 34′ 33.3″ W | {{val|3471.3|u=m}} |- | Big Bear Solar Observatory | 34° 15′ 37.2″ N | data-sort-value=-116 | 116° 55′ 17.1″ W | {{val|2063.1|u=m}} |- | Cerro Tololo Inter-American Observatory | data-sort-value=-30 | 30° 10′ 4.2″ S | data-sort-value=-70 | 70° 48′ 19.7″ W | {{val|2190.0|u=m}} |- | Teide Observatory | 28° 18′ 3.0″ N | data-sort-value=-16 | 16° 30′ 43.0″ W | {{val|2425.0|u=m}} |- | Udaipur Solar Observatory | 24° 36′ 53.8″ N | 73° 40′ 10.9″ E | {{val|676.9|u=m}} |- | Learmonth Solar Observatory | data-sort-value=-22 | 22° 13′ 6.6″ S | 114° 6′ 9.8″ E | {{val|14.7|u=m}} |}
==Gallery== <gallery mode="packed" heights="140"> File:GONG at Learmonth.jpg|GONG shelter in Learmonth, Australia File:Mauna loa clouds.jpg|GONG shelter at Mauna Loa, Hawai'i File:GONG at BBSO.jpg|GONG at Big Bear Solar Observatory, California </gallery>
== External links == *[https://gong.nso.edu GONG info] at the National Solar Observatory site
== References == {{Reflist}}
Category:Solar observatories