Hidden Views of Vast Stellar Nurseries Unveiled in Epic Million-Image Mosaic

L1688 Region in Ophiuchus

This image shows the L1688 region in the Ophiuchus constellation. New stars are born in the colorful clouds of gas and dust seen here. The infrared observations underlying this image reveal new details in the star-forming regions that are usually obscured by the clouds of dust. The image was produced with data collected by the VIRCAM instrument, which is attached to the VISTA telescope at ESO’s Paranal Observatory in Chile. The observations were done as part of the VISIONS survey, which will allow astronomers to better understand how stars form in these dust-enshrouded regions. Credit: ESO/Meingast et al.

Astronomers have used VISTA to create an infrared atlas of five stellar nurseries, offering unprecedented insights into star formation and revealing previously unseen objects. The VISIONS atlas will serve as a valuable resource for years and lay the foundation for future observations.

Using the Visible and Infrared Survey Telescope for Astronomy (VISTA), astronomers have created an extensive infrared atlas of five nearby stellar nurseries by combining over one million images. This atlas provides insights into the complex process of star formation and reveals previously unseen objects. The VISIONS survey captured images of star-forming regions in various constellations and observed the same areas repeatedly to study the motion of young stars. The VISIONS atlas will be valuable for astronomers for years to come and will set the groundwork for future observations with other telescopes, such as ESO’s Extremely Large Telescope (ELT).

Using ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA), astronomers have created a vast infrared atlas of five nearby stellar nurseries by piecing together more than one million images. These large mosaics reveal young stars in the making, embedded in thick clouds of dust. Thanks to these observations, astronomers have a unique tool with which to decipher the complex puzzle of stellar birth.

“In these images we can detect even the faintest sources of light, like stars far less massive than the Sun, revealing objects that no one has ever seen before,” says Stefan Meingast, an astronomer at the University of Vienna in Austria and lead author of the new study published on May 11 in Astronomy & Astrophysics. “This will allow us to understand the processes that transform gas and dust into stars.”

Lupus 2 Region Infrared

This image shows the region Lupus 2. New stars are born in the colorful clouds of gas and dust seen here. Credit: ESO/Meingast et al.

Lupus 3 Region Infrared

This image shows the region Lupus 3. New stars are born in the colorful clouds of gas and dust seen here. Credit: ESO/Meingast et al.

Stars form when clouds of gas and dust collapse under their own gravity, but the details of how this happens are not fully understood. How many stars are born out of a cloud? How massive are they? How many stars will also have planets?

To answer these questions, Meingast’s team surveyed five nearby star-forming regions with the VISTA telescope at ESO’s Paranal Observatory in Chile. Using VISTA’s infrared camera VIRCAM, the team captured light coming from deep inside the clouds of dust. “The dust obscures these young stars from our view, making them virtually invisible to our eyes. Only at infrared wavelengths can we look deep into these clouds, studying the stars in the making,” explains Alena Rottensteiner, a PhD student also at the University of Vienna and co-author of the study.

HH 909 A Object in Chamaeleon Infrared

This image shows the HH 909 A object in the Chamaeleon constellation. New stars are born in the colorful clouds of gas and dust seen here. Credit: ESO/Meingast et al.

IRAS 11051-7706 Object in Chamaeleon Infrared

This image shows the IRAS 11051-7706 object in the Chamaeleon constellation. New stars are born in the colorful clouds of gas and dust seen here. Credit: ESO/Meingast et al.

The survey, called VISIONS, observed star-forming regions in the constellations of Orion, Ophiuchus, Chamaeleon, Corona Australis, and Lupus. These regions are less than 1500 light-years away and so large that they span a huge area in the sky. The diameter of VIRCAM’s field of view is as wide as three full Moons, which makes it uniquely suited to map these immensely big regions.

The team obtained more than one million images over a period of five years. The individual images were then pieced together into the large mosaics released here, revealing vast cosmic landscapes. These detailed panoramas feature dark patches of dust, glowing clouds, newly-born stars, and the distant background stars of the Milky Way.

Region Around Coronet Star Cluster Infrared

This image shows the regions around the Coronet star cluster in the Corona Australis constellation. New stars are born in the colorful clouds of gas and dust seen here. Credit: ESO/Meingast et al.

L1688 Region Visible Light

This image shows the environment around the L1688 star-forming region in visible light. This area, located in the Ophiuchus constellation, features prominent dark lanes and glowing nebulae. This image was taken from ESO’s Paranal Observatory with a 10-cm Takahashi FSQ106Ed f/3.6 telescope and a SBIG STL CCD camera, as part of the Gigagalaxy Zoom project. Credit: ESO/S. Guisard

Since the same areas were observed repeatedly, the VISIONS data will also allow astronomers to study how young stars move. “With VISIONS we monitor these baby stars over several years, allowing us to measure their motion and learn how they leave their parent clouds,” explains João Alves, an astronomer at the University of Vienna and Principal Investigator of VISIONS. This is not an easy feat, as the apparent shift of these stars as seen from Earth is as small as the width of a human hair seen from 10 kilometers away. These measurements of stellar motions complement those obtained by the European Space Agency’s Gaia mission at visible wavelengths, where young stars are hidden by thick veils of dust.

Lupus 3 Region Visible Light

A dark cloud of cosmic dust snakes across this spectacular image, illuminated by the brilliant light of new stars. This dense cloud is a star-forming region called Lupus 3, where dazzlingly hot stars are born from collapsing masses of gas and dust. This image was created from images taken using the VLT Survey Telescope and the MPG/ESO 2.2-meter telescope. Credit: ESO/R. Colombari

Coronet Region Visible Light

This image, taken with the Wide Field Imager on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile, shows the nearby star-forming region around the Coronet star cluster, in the Corona Australis constellation. Credit: ESO

The VISIONS atlas will keep astronomers busy for years to come. “There is tremendous long-lasting value for the astronomical community here, which is why ESO steers Public Surveys like VISIONS,” says Monika Petr-Gotzens, an astronomer at ESO in Garching, Germany, and co-author of this study. Moreover, VISIONS will set the groundwork for future observations with other telescopes such as ESO’s Extremely Large Telescope (ELT), currently under construction in Chile and set to start operating later this decade. “The ELT will allow us to zoom into specific regions with unprecedented detail, giving us a never-seen-before close-up view of individual stars that are currently forming there,” concludes Meingast.


This video takes us on a journey to the L1688 region, where new stars are being born. We first see the Milky Way in visible light, and then we switch to an infrared view, which reveals young stars hidden by dust in this region. Credit: ESO, N. Risinger (skysurvey.org), DSS, S. Guisard, Meingast et al. Music: Johan B. Monell

Reference: “VISIONS: The VISTA Star Formation Atlas” by Stefan Meingast, João Alves, Hervé Bouy, Monika G. Petr-Gotzens, Verena Fürnkranz, Josefa E. Großschedl, David Hernandez, Alena Rottensteiner, Magda Arnaboldi, Joana Ascenso, Amelia Bayo, Erik Brändli, Anthony G.A. Brown, Jan Forbrich, Alyssa Goodman, Alvaro Hacar, Birgit Hasenberger, Rainer Köhler, Karolina Kubiak, Michael Kuhn, Charles Lada, Kieran Leschinski, Marco Lombardi, Diego Mardones, Laura Mascetti, Núria Miret-Roig, André Moitinho, Koraljka Mužic, Martin Piecka, Laura Posch, Timo Prusti, Karla Peña Ramírez, Ronny Ramlau, Sebastian Ratzenböck, Germano Sacco, Cameren Swiggum, Paula Stella Teixeira, Vanessa Urban, Eleonora Zari and Catherine Zucker, 11 May 2023, Astronomy & Astrophysics.
DOI: 10.1051/0004-6361/202245771

The team is composed of Stefan Meingast (University of Vienna, Austria [Vienna]), João Alves (Vienna), Hervé Bouy (Université de Bordeaux, France [Bordeaux]), Monika G. Petr-Gotzens (European Southern Observatory, Germany [ESO]), Verena Fürnkranz (Max-Planck-Institut für Astronomie, Germany [MPIA]]), Josefa E. Großschedl (Vienna), David Hernandez (Vienna), Alena Rottensteiner (Vienna), Joana Ascenso (Universidade do Porto, Portugal [Porto]; Universidade de Lisboa, Portugal [Lisboa]), Amelia Bayo (ESO; Universidad de Valparaíso, Chile), Erik Brändli (Vienna), Anthony G. A. Brown (Leiden University, Netherlands), Jan Forbrich (University of Hertfordshire, UK [Hertfordshire]), Alyssa Goodman (Harvard-Smithsonian Center for Astrophysics, USA [CfA]), Alvaro Hacar (Vienna), Birgit Hasenberger (Vienna), Rainer Köhler (The CHARA Array of Georgia State University, USA), Karolina Kubiak (Lisboa), Michael Kuhn (Hertfordshire), Charles Lada (CfA), Kieran Leschinski (Vienna), Marco Lombardi (Università degli Studi di Milano, Italy), Diego Mardones (Universidad de Chile, Chile), Núria Miret-Roig (European Space Agency, European Space Research and Technology Centre, Netherlands [ESA]), André Moitinho (Lisboa), Koraljka Mužiiic (Porto; Lisboa), Martin Piecka (Vienna), Laura Posch (Vienna), Timo Prusti (ESA), Karla Peña Ramírez (Universidad de Antofagasta, Chile), Ronny Ramlau (Johannes Kepler University Linz, Austria; Johann Radon Institute for Computational and Applied Mathematics, Austria), Sebastian Ratzenböck (Vienna; Research Network Data Science at Uni Vienna), Germano Sacco (INAF – Osservatorio Astrofisico di Arcetri, Italy), Cameren Swiggum (Vienna), Paula Stella Teixeira (University of St Andrews, UK), Vanessa Urban (Vienna), Eleonora Zari (MPIA), and Catherine Zucker (Bordeaux).