Over 1000 studies using ESO data: a look back at ESO’s science results of 2020

20 May 2021

ESO observatories operated under challenging conditions in 2020 due to the unprecedented COVID-19 pandemic, having to reduce and even pause scientific observations for a few months. Nonetheless, 2020 was still a very productive year for the observatory with regard to the number of papers that were published using data from ESO telescopes, mostly obtained in previous years. A recently published report from the ESO library shows that 2020 represents the fourth consecutive year that over 1000 scientific studies using ESO data were published.

The majority of these publications, more than 600, used data from ESO’s flagship facility, the Very Large Telescope (VLT), and the VLT Interferometer (VLTI). Highlights include the first ever image of a multi-planet system around a Sun-like star and observing a star “dance” around a supermassive black hole.

Of the 608 studies carried out using observations from the VLT and VLTI, 336 (55%) used data from the Multi Unit Spectroscopic Explorer (MUSE), the Ultraviolet-Visual Echelle Spectrograph (UVES), or from the X-shooter spectrograph. These were the three most productive VLT instruments in 2020, as was the case in 2019.

Data from the survey telescopes at ESO’s Paranal Observatory in northern Chile, the Visible and Infrared Survey Telescope for Astronomy (VISTA) and the VLT Survey Telescope (VST), led to over 150 published papers in 2020, in line with previous years. One result, which used data from the VST, combined with data from ESO’s VLT and the New Technology Telescope, showed how hot stars are plagued by giant magnetic spots.

Approximately 200 papers were published using data obtained from ESO’s oldest observatory, La Silla. Of these, a significant portion (122) came from the High Accuracy Radial velocity Planet Searcher (HARPS), an instrument mounted on ESO’s 3.6-metre telescope that is dedicated to the search for, and study of, exoplanets.

The Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, provided data for over 440 papers. Almost half (48%) of these used data obtained during European ALMA time. An example includes a study on the interstellar thread of one of life’s building blocks, published in January 2020.

ESO is also a partner in the Atacama Pathfinder Experiment (APEX), which is located near ALMA on the Chajnantor plateau in Chile’s Atacama region. In 2020, observations obtained during ESO observing time at APEX contributed to more than half (56%) of papers from all APEX observing time.

For the second year running, more than a third (36%) of all ESO data papers published in 2020 used observations that came partly or exclusively from the ESO Science Archive. This highlights the fact that past observations continue to be used by astronomers and lead to further breakthroughs in science — sometimes years after they have initially been taken. Although data obtained this year will be lower due to the closure of observatory sites, older ESO data is still being used and will continue to contribute to astronomy.

These impressive publication numbers highlight ESO’s important role in helping astronomers further our knowledge of the Universe. Comparing publication statistics for ESO and other observatories is complicated by the fact that different institutes use different methods to count scientific studies; nonetheless, ESO has remained the world’s most productive ground-based observatory in 2020, with over 1000 papers published using ESO data.

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

Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Tel: +49 89 3200 6670

About the Announcement



Number of papers published using observational data from different observatories (1996–2020)
Number of papers published using observational data from different observatories (1996–2020)
Number of papers published using different ESO telescopes (1996–2020)
Number of papers published using different ESO telescopes (1996–2020)