The Most Productive Ground-based Observatory: A Look Back at ESO’s Science Results of 2019

9 April 2020

Science observations at ESO’s sites in Chile may have paused last month, but data collected by our telescopes in the past continues to further astronomy years after the observations are conducted. A recently released report by the ESO Library shows that, in 2019 alone, over 1000 publications were published using data from ESO telescopes.

The largest contribution to this total comes from ESO’s Very Large Telescope (VLT) and the VLT Interferometer at ESO’s Paranal Observatory in Chile. In 2019, a total of 597 scientific studies were published using data from the facilities. The most productive instruments were UVES, MUSE, and X-shooter with each instrument contributing to over 100 papers individually. 

A few key results to have come out of ESO’s flagship facility, the VLT, in 2019 included: Finding the first gas giant planet orbiting a Sun-like star remnant and the first detection of a heavy element born in the aftermath of a neutron star merger

ESO’s other telescopes at Paranal, VISTA (Visible and Infrared Survey Telescope for Astronomy) and VST (VLT Survey Telescope) made significant contributions as well. In 2019, VISTA and VST data were used in 98 and 55 scientific studies respectively. These include a study where VISTA unveiled a new image of the Large Magellanic Cloud, making about 10 million more individual stars visible, and one on how the VST helped determine Gaia’s orbit to best map the Milky Way.

ESO’s La Silla Observatory turned 50 this past year, the anniversary culminating with a total solar eclipse. Data from La Silla contributed to 207 scientific studies published last year, showing that, even after half a century of observation, La Silla continues to deliver remarkable science. 

The Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, provided data for 219 papers specifically using European ALMA time allocation, while ESO’s APEX, the Atacama Pathfinder EXperiment, contributed data to a total of 32 scientific studies. 

The Basic ESO Publication Statistics report, where the figures are published annually, also highlights that the number of papers published using data from the ESO archive has continued to increase. In 2019, 35% of the over 1000 papers published relied on the use of archive data, either by using exclusively archival ESO data (where none of authors were among the team of observers) or by deploying archival data along with data obtained by the authors.

These publication numbers highlight ESO’s contribution to astronomical research, while the few key results showcased give an idea of the important scientific work conducted with its telescopes. While comparisons between ESO and other observatories are complicated by the different methods used to count scientific studies, ESO remains the world’s most productive ground-based observatory.

More Information

The figures are published in the annual Basic ESO Publication Statistics published by ESO’s Library and Information Centre and calculated using the ESO Telescope Bibliography(telbib), a database containing refereed publications that use ESO data. ESO makes extensive efforts to identify all refereed papers that use ESO data and considers telbib essentially complete. 

Interactive graphs of selected statistics are available online. These graphs display the entire content of the telbib database, which contains records for publications from 1996 to the present. They can be used to explore many aspects of the publication history, including the development of science papers using data from ESO instruments and the use of archival data. 

ALMA, an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile.



Uta Grothkopf
ESO Librarian
Garching bei München, Germany
Tel: +49 89 3200 6280

Bárbara Ferreira
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6670

About the Announcement



Number of papers published using observational data from different observatories (1996–2019)
Number of papers published using observational data from different observatories (1996–2019)