Completion of the largest infrared map of the Milky Way

The data gathered provides unprecedented insights into the structure and composition of the Milky Way.

The VISTA (Visible and Infrared Survey Telescope for Astronomy), a European Southern Observatory (ESO) facility in Chile, has successfully mapped over 1.5 billion objects in the Milky Way.

Over the course of 13 years, the VISTA Variables in the Vía Láctea (VVV) survey and its extension, the VVV eXtended survey (VVVX), observed the central regions of the Milky Way. Beginning in 2010, these surveys required 420 nights of observation to capture approximately 200,000 images, monitoring over 1.5 billion celestial objects and generating 500 terabytes of scientific data. This represents the largest volume of data ever collected for an ESO observational project.

Notable discoveries

The data gathered provides unprecedented insights into the structure and composition of the Milky Way, the galaxy that contains our own Solar System. Notable discoveries include:

• Globular clusters: the oldest objects in our Galaxy.
• Hypervelocity stars: stars expelled from the Galaxy by the central supermassive black hole.
• Galactic windows: clear views through interstellar dust and gas to the other side of the Galaxy.
• RR Lyrae variable stars: the oldest known population in the centre of the Galaxy.
• Brown dwarf stars and binary floating planets: unique celestial objects that enhance our understanding of stellar and planetary formation.

UK role on VISTA

The University of Edinburgh is one of 18 UK universities which form part of the VISTA Consortium who work closely together with scientists from the Science and Technology Facilities Council through its team at the UK Astronomy Technology Centre (UK ATC) to play a role in the development and delivery of the telescope to the ESO.

Edinburgh involvement

The Wide-Field Astronomy Unit (WFAU) in the University of Edinburgh’s Institute for Astronomy curates and publishes the VVV/VVVX data, along with that from the other public surveys conducted with the VISTA telescope, in its VISTA Science Archive (VSA).

The WFAU Director, Prof Bob Mann said:

Members of the WFAU team – led by Dr Nick Cross – have been working closely with the VVV/VVVX consortium since their survey started. The VSA provides a long-term home for their survey data and many additional data products derived by the consortium, ensuring that their vast, and wonderfully rich, dataset will remain accessible to astronomers. Sky survey data has a scientific longevity, and researchers will be extracting exciting science from the VVV/VVVX dataset for many years to come.