As part of the VISIONS survey program, astronomers have surveyed five nearby star-forming molecular cloud complexes associated with the constellations of Chamaeleon, Corona Australis, Lupus, Ophiuchus, and Orion, with ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA) at Paranal Observatory.
Ongoing star formation processes as observed by VIRCAM/VISTA in the VISIONS program. The top panel shows L1688 in the Ophiuchus star-forming complex, depicting several dozen prominent young stellar objects located within one of the closest embedded clusters to Earth. The young stars are surrounded by a highly structured cloud composed of gas and dust that is largely being shaped by young, optically revealed hot stars in the vicinity. The bottom panels further highlight the complex morphology of the gaseous, dusty neighborhood of partly concealed young stars in the Ophiuchus molecular clouds L1709 and L1689. Image credit: Meingast et al., doi: 10.1051/0004-6361/202245771.
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, University of Vienna astronomer Stefan Meingast and colleagues surveyed five nearby star-forming regions with the VISTA Infrared Camera (VIRCAM) on the VISTA telescope.
These regions are located less than 1,500 light-years away in the constellations of Orion, Ophiuchus, Chamaeleon, Corona Australis and Lupus.
“In the VISIONS 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,” Dr. Meingast said.
“This will allow us to understand the processes that transform gas and dust into stars.”
Using the VIRCAM instrument, the astronomers 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,” said University of Vienna Ph.D. student Alena Rottensteiner.
“Only at infrared wavelengths can we look deep into these clouds, studying the stars in the making.”
Over a period of five years, the researchers obtained more than one million images of the five star-forming regions.
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,” said Dr. João Alves, an astronomer at the University of Vienna.
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,” said Dr. Monika Petr-Gotzens, an astronomer at ESO.
“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.”
“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,” Dr. Meingast said.
The findings appear in the journal Astronomy & Astrophysics.
_____
Stefan Meingast et al. 2023. VISIONS: the VISTA Star Formation Atlas I. Survey overview. A&A 673, A58; doi: 10.1051/0004-6361/202245771
