2023-05-15 11:15:38
Astronomers have managed to map five nearby stellar nurseries in greater detail than ever before.
Using the European Southern Observatory’s (ESO’s) Visible and Infrared Survey Telescope for Astronomy (VISTA), a team of astronomers has created a vast infrared atlas of five nearby stellar nurseries by collecting more than one million images. These large mosaics reveal the presence of young forming stars embedded in thick clouds of dust. Thanks to these observations, the astronomical community now has a unique tool with which to decipher the complex puzzle of stellar birth.
The team is led by Stefan Meingast and João Alves from the University of Vienna in Austria, Hervé Bouy from the University of Bordeaux in France and Monika G. Petr-Gotzens from ESO.
“In these images we can detect even the faintest light sources, such as stars much less massive than the Sun, revealing objects that no one has seen before,” says Meingast. “This will allow us to understand the processes that transform gas and dust into stars.”
Stars form when clouds of gas and dust collapse under their own gravity, but we don’t yet have all the details of how this process happens. How many stars are born from a cloud? How massive are they? How many stars will also have planets?
To answer these questions, Meingast’s team probed five nearby star-forming regions with the VISTA telescope at ESO’s Paranal Observatory in Chile. Using VISTA’s VIRCAM infrared camera, the team captured light coming from deep within the dust clouds. “The dust obscures these young stars, making them virtually invisible to our eyes. Only at infrared wavelengths can we penetrate into the depths.” of these clouds and study the forming stars,” explains Alena Rottensteiner, a doctoral student also at the University of Vienna and a co-author of the study.
The survey, called VISIONS, observed star-forming regions in the constellations Orion, Ophiuchus, Chameleon, Corona Australis and Lupus. These regions are less than 1,500 light-years away and are so large that they span an enormous area of the sky. VIRCAM’s diameter field of view is as wide as three full moons, making it especially well-suited for mapping these immensely large regions.
The team obtained more than a million images over a five-year period. The individual images were put together in the great mosaics, revealing vast cosmic landscapes. These detailed panoramas feature dark patches of dust, bright clouds, newborn stars, and the distant background stars of the Milky Way.
Since the same areas were observed repeatedly, the VISIONS data will also allow the astronomical community to study how young stars move. “With VISIONS we monitor these baby stars for several years, which allows us to measure their movement and learn how they emerge from their parent clouds,” explains João Alves, an astronomer at the University of Vienna and principal investigator for VISIONS. This is not easy, since the apparent change of these stars 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 (ESA) Gaia mission at visible wavelengths, where young stars are obscured by thick veils of dust.
This image shows the region of Lupus 3. New stars are being born in the colorful clouds of gas and dust seen here. The infrared observations that have led to this image reveal new details in star-forming regions that are generally obscured by dust clouds. The image was produced with data collected by the VIRCAM instrument, installed on the VISTA telescope, at ESO’s Paranal Observatory, in Chile. The observations were made as part of the VISIONS survey, which will allow the astronomical community to better understand how stars form in these dust-shrouded regions. (Image: ESO/Meingast et al.)
The VISIONS atlas will keep the astronomy community busy for years to come. “This has great long-term value for the astronomical community, and is why ESO promotes public surveys like VISIONS,” says Monika Petr-Gotzens, ESO astronomer in Garching, Germany, and co-author of this study. . In addition, VISIONS will lay the foundations for future observations with other telescopes such as ESO’s ELT (Extremely Large Telescope), currently under construction in Chile, which will start operating at the end of this decade. “The ELT will allow us to zoom in on specific regions in unprecedented detail, giving us a never-before-seen close-up view of individual stars forming there right now,” concludes Meingast.
Meingast and his colleagues report the technical details of the survey and the main findings they have achieved with it in the academic journal Astronomy & Astrophysics, under the title “VISIONS: The VISTA Star Formation Atlas.” (Source: IT. CC BY 4.0)
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