Editing European VLBI Network

{{Short description|Network of radio telescopes across Europe that link together for radio interferometry}}
{{more citations needed|date=December 2018}}
{{Infobox observatory}}
The '''European VLBI Network''' ('''EVN''') is a network of radio telescopes located primarily in Europe and Asia, with additional antennas in South Africa and Puerto Rico, which performs very high angular resolution observations of cosmic radio sources using [[very-long-baseline interferometry]] (VLBI). The EVN is the most sensitive VLBI array in the world, and the only one capable of real-time observations. The [[Joint Institute for VLBI ERIC]] (JIVE) acts as the central organisation in the EVN, providing both scientific user support and a correlator facility. Very Long Baseline Interferometry (VLBI) achieves ultra-high angular resolution and is a multi-disciplinary technique used in astronomy, geodesy and astrometry.

The EVN operates an open-sky policy, allowing anyone to propose an observation using the network<ref>{{Cite web|url=https://www.evlbi.org/using-evn|title=Using the EVN {{!}} EVLBI|website=www.evlbi.org|access-date=2020-02-07}}</ref>

== EVN Telescopes ==
The EVN network comprises 22 telescope facilities:<ref>{{cite web | title = Pictures of EVN telescopes | url = http://www.evlbi.org/intro/intro.html | access-date = 2018-09-26 | archive-url = https://web.archive.org/web/20120224193835/http://www.evlbi.org/intro/intro.html | archive-date = 2012-02-24 | url-status = dead }}</ref>

{| class="wikitable"
! Name
! Dish Size
! Location
! Operated by
|-----
| [[Effelsberg 100-m Radio Telescope]]
| 100 metres
| {{Flagicon|Germany}} [[Effelsberg]], [[Germany]]
| [[Max Planck Institute for Radio Astronomy]]
|-----
| [[Westerbork Synthesis Radio Telescope]]
| 12 x 25 metres
| {{Flagicon|Netherlands}} [[Westerbork (village)|Westerbork]], [[Netherlands]]
| [[ASTRON]]
|-----
| [[Sardinia Radio Telescope]]
| 64 metres
| {{Flagicon|Italy}} [[San Basilio, Sardinia|San Basilio]], [[Italy]]
| [[Istituto Nazionale di Astrofisica]]
|-----
| [[Lovell Telescope]]
| 76 metres
| {{Flagicon|UK}} [[Goostrey]], [[Cheshire]], [[United Kingdom]]
| [[Jodrell Bank Observatory]]
|-----
| [[Cambridge 32 metres]]
| 32 metres
| {{Flagicon|UK}} [[Mullard Radio Astronomy Observatory]], [[United Kingdom]]
| [[Jodrell Bank Observatory]]
|-----
| [[Mark II (radio telescope)|Mark II]]
| 25 metres
| {{Flagicon|UK}} [[Goostrey]], [[Cheshire]], [[United Kingdom]]
| [[Jodrell Bank Observatory]]
|-----
| [[Medicina Radio Observatory]]
| 32 metres
| {{Flagicon|Italy}} [[Medicina]], [[Italy]]
| [[Istituto Nazionale di Astrofisica]]
|-----
| [[Onsala Space Observatory]]
| 25 metres and 20 metres
| {{Flagicon|Sweden}} [[Onsala]], [[Sweden]]
| [[Chalmers University of Technology]]
|-----
| [[Ventspils International Radio Astronomy Centre]]
| 32 metres and 16 metres
| {{Flagicon|Latvia}} [[Ventspils]], [[Irbene]], [[Latvia]]
| [[Ventspils University College]]
|-----
| [[Noto Radio Observatory]]
| 32 metres
| {{Flagicon|Italy}} [[Noto]], [[Italy]]
| [[Istituto Nazionale di Astrofisica]]
|-----
| [[Toruń Centre for Astronomy]]
| 32 metres
| {{Flagicon|Poland}} [[Toruń]], [[Poland]]
| [[Nicolaus Copernicus University]]
|-----
| [[Metsähovi Radio Observatory]]
| 14 metres
| {{Flagicon|Finland}} [[Kirkkonummi]], [[Finland]]
| [[Aalto University]]
|-----
| [[Sheshan 25 metres]]
| 25 metres
| {{Flagicon|China}} [[Sheshan Island|Sheshan]], [[Shanghai]], [[China]]
| [[Shanghai Astronomical Observatory]]
|-----
| [[Xinjiang Astronomical Observatory|Nanshan 25 metres]]
| 25 metres
| {{Flagicon|China}} [[Ürümqi]], [[China]]
| 
|-----
| [[Spanish National Observatory]]
| 40 metres and 14 metres
| {{Flagicon|Spain}} [[Yebes]], [[Province of Guadalajara|Guadalajara]], [[Spain]]
| [[Instituto Geográfico Nacional (Spain)]]
|-----
| [[Wettzell (20m Radio telescope)]]
| 20 metres
| {{Flagicon|Germany}} [[Germany]]
|[[Federal Agency for Cartography and Geodesy|Bundesamt für Kartographie und Geodäsie]] (BKG) [[Technical University of Munich|Technische Universität München]] (TUM)
|-----
| [[Madrid Deep Space Communication Complex]]
| 70 metres
34 metres
| {{Flagicon|Spain}} [[Robledo de Chavela]], [[Spain]]
| [[Instituto Nacional de Técnica Aeroespacial|INTA]] / [[NASA]] / [[JPL]]
|-----
| [[Hartebeesthoek Radio Astronomy Observatory]]
| 26 metres
| {{Flagicon|South Africa}} [[Hartebeesthoek]], [[South Africa]]
| [[National Research Foundation of South Africa]]
|-----
| [[Arecibo Observatory]]
| 305 metres
| {{Flagicon|USA}} [[Arecibo]], [[Puerto Rico]]
| [[SRI International]] / [[Universities Space Research Association|USRA]] / [[Metropolitan University (Puerto Rico)|UMET]]
|-----
| [[:eo:Radioastronomia observatorio Svetloje|RAO Svetloe]]
| 32 metres
| {{Flagicon|Russia}} [[Leningrad Oblast|Leningrad]], [[Russia]]
| [[:ru:Институт прикладной астрономии РАН|Institute of Applied Astronomy]]
|-----
| [[:eo:Radioastronomia observatorio Zelenĉuka|RAO Zelenchuckskaya]]
| 32 metres
| {{Flagicon|Russia}} [[Zelenchukskaya]], [[Zelenchuksky District|Zelenchuksky]], [[Karachay-Cherkessia]], [[Russia]]
| [[:ru:Институт прикладной астрономии РАН|Institute of Applied Astronomy]]
|-----
| [[:eo:Radioastronomia observatorio Badaro|RAO Badary]]
| 32 metres
| {{Flagicon|Russia}} [[Badary]], [[Tunkinsky District|Tunkinsky]], [[Buryatia]], [[Russia]]
| [[:ru:Институт прикладной астрономии РАН|Institute of Applied Astronomy]]
|}

Additionally the EVN often links with the UK-based 7-element [[Jodrell Bank]] [[MERLIN]] interferometer. It can also be connected to the US [[Very Long Baseline Array]] (VLBA), achieving a global [[VLBI]], obtaining sub-milliarcsecond resolution at frequencies higher than 5&nbsp;GHz.<ref>{{cite web | title = Introduction to the EVN | url = http://www.evlbi.org/intro/intro.html | access-date = 2014-02-03 | archive-url = https://web.archive.org/web/20120224193835/http://www.evlbi.org/intro/intro.html | archive-date = 2012-02-24 | url-status = dead }}</ref>

== e-EVN ==
Since 2004, the EVN has started to be linked together using international fibre optic networks, through a technique known as [[e-VLBI]]. The EXPReS project was designed to connect telescopes at Gigabit per second links via their National Research Networks and the Pan-European research network [[GÉANT2]], and make the first astronomical experiments using this new technique. This allows researchers to take advantage of the e-EVN's Targets of Opportunity for conducting follow-on observations of transient events such as [[X-ray binary]] flares, [[supernova]] explosions and [[gamma-ray bursts]].

EXPReS's objectives are to connect up to 16 of the world's most sensitive radio telescopes on six continents to the central data processor of the European VLBI Network at the [[Joint Institute for VLBI ERIC]] (JIVE). Specific activities involve securing "last-mile connections" and upgrading existing connections to the telescopes, updating the correlator to process up to 16 data streams at 1&nbsp;Gbit/s each in real time and research possibilities for distributed computing to replace the centralized data processor.

== History ==
The EVN was formed in 1980 by a consortium of five of the major radio astronomy institutes in [[Europe]] (the European Consortium for VLBI). Since 1980, the EVN and the Consortium has grown to include many institutes with numerous [[radio telescopes]] in several western European countries as well as associated institutes with telescopes in Russia, Ukraine, China and South Africa. Proposals for an additional telescope in Spain are under consideration.

Observations using the EVN have contributed to scientific research on [[Fast Radio Burst]]s (FRBs),<ref>{{Cite web|url=http://www.jive.eu/repeating-fast-radio-burst-spiral-galaxy-deepens-mystery-where-these-signals-originate|title=A repeating Fast Radio Burst from a spiral galaxy deepens the mystery of where these signals originate from {{!}} Jive|website=www.jive.eu|access-date=2020-02-07}}</ref> gravitational lensing,<ref>{{Cite web|url=http://www.jive.eu/new-images-super-telescope-bring-astronomers-step-closer-understanding-dark-matter|title=New images from a super-telescope bring astronomers a step closer to understanding dark matter {{!}} Jive|website=www.jive.eu|language=en|access-date=2020-02-07}}</ref> and supermassive black holes.<ref>{{Cite web|url=http://www.jive.eu/surprise-discovery-provides-new-insights-stellar-deaths|title=Surprise discovery provides new insights into stellar deaths {{!}} Jive|website=www.jive.eu|language=en|access-date=2020-02-07}}</ref>

== See also ==
* [[Northern Extended Millimeter Array]]

== References ==
{{Reflist}}

== External links ==
*{{Commons category-inline}}
*[https://www.evlbi.org/ The European VLBI Network] on the internet
*[http://www.jive.eu Joint Institute for VLBI ERIC] on the internet

{{Radio-astronomy}}
{{Authority control}}

[[Category:Astronomy in Europe]]
[[Category:Interferometric telescopes]]
[[Category:Radio telescopes]]