Global Web Tour of EHT Observatories

The Event Horizon Telescope is a global network of synchronized radio observatories that work in unison to observe radio sources associated with black holes with angular resolution comparable to their event horizons. The required extreme resolving power makes scientists and engineers go to some of the most extreme environments on the Earth to collect data. On EHT social media pages, Twitter  and Facebook, and in this blog post we are taking you on a tour to the 8 observatories that participated in acquisition of the 2017 EHT data, as well as to another 3 that will will be a part of this daring endeavor beyond 2017. Find them all on this interactive map here on the official EHT website!

Eight observatories that participated in EHT observations in 2017 (and later):

The APEX telescope at sunset during the EHT 2018 observing campaign
Sunset over the Atacama desert, Chile, the home of the APEX observatory. Credit: Sven Dornbusch

Atacama Pathfinder Experiment (APEX)
Cerro Chajnantor, Chile
altitude: 5,100 m
single dish, 12-m diameter

web: Tw, Fb, www.eso.org/apex

Operated by the European Southern Observatory (ESO, @ESO, @ESOAstronomy) on behalf of Max Planck Institut fuer Radioastronomie (MPIfR, @maxplanckpress, @maxplancksociety), Onsala Space Observatory (@OnsalaRymd, @onsalarymd), and ESO itself.

Snowy sunrise at the Chajnantor Plateau with ALMA.
Snowy sunrise at the Chajnantor Plateau with ALMA. Credit: NAOJ/NRAO/ESO.

Atacama Large Millimeter/submillimeter Array (ALMA)
Cerro Chajnantor, Chile
altitude: about 5,000 m
array of fifty-four 12-m diameter and twelve 7-m diameter dishes

web: Tw, Fb, https://www.almaobservatory.org/

ALMA is the result of an international association between Europe (ESO, @ESO, @ESOAstronomy), North America (NRAO, @TheNRAO, @TheNRAO) and East Asia (NAOJ, @naoj.eng, @prcnaoj_en), in collaboration with the Republic of Chile.

IRAM 30-meter telescope under the moonlight.
IRAM 30-meter telescope in snow under the moonlight. Credit: IRAM, N. Billot.

IRAM 30-meter Telescope
Pico Veleta, Spain
altitude: 2,850 m
single dish, 30-m diameter

web: http://www.iram-institute.org/EN/30-meter-telescope.php

Operated by Institut de Radioastronomie Millimétrique (IRAM), a collaboration between Centre National de la Recherche Scientifique (CNRS, @CNRS, @CNRS.fr), Max-Planck-Gesellschaft (@maxplanckpress, @maxplancksociety), and Instituto Geográfico Nacional (IGN, @IGNSpain, @IGNSpain).

JCMT while observing with telescope covered.
JCMT while observing at night with telescope covered. Credit: EAO, William Montgomerie.

James Clerk Maxwell Telescope (JCMT)
Maunakea, Hawaii, USA
altitude: 4,100 m
single dish, 15-m diameter

web: Tw, Fb, https://www.eaobservatory.org/jcmt/

Operated by East Asia Observatory (EAO, @EAObservatory) on behalf of National Astronomical Observatories, Chinese Academy of Sciences, National Astronomical Observatory of Japan (NAOJ, @naoj.eng, @prcnaoj_en), Korea Astronomy and Space Science Institute (KASI, @kasi.re.kr), and Academia Sinica Institute for Astronomy and Astrophysics (ASIAA, @epo_asiaa, @asiaa.tw). EAO also partners with Vietnam, Thailand, Malaysia, India and Indonesia.

Large Millimeter Telescope "Alfonso Serrano" at sunset.
Large Millimeter Telescope "Alfonso Serrano" with completed 50-meter surface pointing upward at sunset. Credit: INAOE Archives.

Large Millimeter Telescope "Alfonso Serrano" (LMT)
Sierra Negra, Mexico
altitude: 4,600 m
single dish, 50-m diameter

web: Tw, Fb, http://www.lmtgtm.org/

Operated by Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE, @inaoe_mx, @inaoe.oficial) and the University of Massachusetts (@UMassAmherst, @UMassAmherst).

All 8 antennas of the SMA in nighttime observation.
All eight antennas of the Submillimeter Array in nighttime observation. Credit: Nimesh Patel.

Submillimeter Array (SMA)
Maunakea, Hawaii, USA
altitude: 4,100 m
array of eight 6-m diameter dishes

web: https://www.cfa.harvard.edu/sma/

Operated by the Smithsonian Astrophysical Observatory (SAO, @saoastro, @HarvardSmithsonianCenterForAstrophysics) and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA, @epo_asiaa, @asiaa.tw).

The Submillimeter Telescope under the night sky.
The Submillimeter Telescope open for observations under the starry sky. Credit: Dave Harvey.

Submillimeter Telescope (SMT)
Mount Graham, Arizona, USA
altitude: 3,100 m
single dish, 10-m diameter

web: http://aro.as.arizona.edu/

Operated by the University of Arizona (@UofA, @uarizona) through the Arizona Radio Observatory (ARO).

The South Pole Telescope observing under polar lights.
Beautiful display of the southern lights (aurora australis) over the South Pole Telescope. Credit: Joshua Montgomery.

South Pole Telescope (SPT)
South Pole Station, Antarctica
altitude: 2,800 m
single dish, 10-m diameter

web: Tw, https://pole.uchicago.edu/

Operated by a collaboration led by the University of Chicago (@UChicago, @uchicago), with EHT instrumentation provided by the University of Arizona (@UofA, @uarizona).

One additional observatory that participated in EHT observations in 2018 (and later):

GLT in a long exposure with star trails.
The Greenland Telescope in a long exposure with star trails. Credit: Ming-Tang Chen.

The Greenland Telescope (GLT)
Thule Air Base, Greenland, Denmark
altitude: 77 m
single dish, 12-m diameter

web: Tw, http://vlbi.asiaa.sinica.edu.tw/project.php
https://www.cfa.harvard.edu/greenland12m

Operated by the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA, @epo_asiaa, @asiaa.tw) and the Smithsonian Astrophysical Observatory (SAO, @saoastro, @HarvardSmithsonianCenterForAstrophysics).

Two additional observatories that will participate in EHT observations in 2020 (and later):

New ALMA prototype dish at Arizona Radio Observatory.
Newly installed ALMA prototype dish at Arizona Radio Observatory. Credit: ARO.

Kitt Peak 12-meter Telescope
Kitt Peak, Arizona, USA
altitude: 1,900 m
single dish, 12-m diameter

website: http://aro.as.arizona.edu/

Operated by the University of Arizona (@UofA, @uarizona) through the Arizona Radio Observatory (ARO).

NOEMA Observatory in compact configuration.
NOEMA Observatory in compact antenna configuration in the French Alps. Credit: IRAM & DiVertiCimes.

NOEMA Observatory
Plateau de Bure, France
altitude: 2,500 m
array of twelve 15-m diameter dishes

web: http://www.iram-institute.org/EN/noema-project.php

Operated by Institut de Radioastronomie Millimétrique (IRAM), a collaboration between Centre National de la Recherche Scientifique (CNRS, @CNRS, @CNRS.fr), Max-Planck-Gesellschaft (@maxplanckpress, @maxplancksociety), and Instituto Geográfico Nacional (IGN, @IGNSpain, @IGNSpain).