The image above is a portion of a new gigantic nine-gigapixel image from the VISTA infrared survey telescope at ESO’s Paranal Observatory of the central portion of the Milky Way Galaxy. The resolution of this image is so great, that if it was printed out in the resolution of a typical book, it would be 9 meters long and 7 meters tall! Click on the image to have access to an interactive, zoomable view of the more than 84 million stars that astronomers have now catalogued from this image. The huge dataset contains more than ten times more stars than previous studies and astronomers say it is a major step forward for the understanding of our home galaxy.
“By observing in detail the myriads of stars surrounding the centre of the Milky Way we can learn a lot more about the formation and evolution of not only our galaxy, but also spiral galaxies in general,” said Roberto Saito from Pontificia Universidad Católica de Chile, Universidad de Valparaíso, lead author of the study.
UPDATE: The image is also available on Gigapan, which provides a very smooth interface in which to explore and zoom around the image.
The dataset contains a treasure trove of information about the structure and content of the Milky Way. One interesting result revealed in the new data is the large number of faint red dwarf stars, which are prime candidates to search for small exoplanets using the transit method. Using this dataset, astronomers can also study the different physical properties of stars such as their temperatures, masses and ages.
To help analyze this huge catalogue, the brightness of each star is plotted against its color for about 84 million stars to create a color–magnitude diagram. This plot contains more than ten times more stars than any previous study and it is the first time that this has been done for the entire bulge.
This infrared view of the central part of the Milky Way from the VVV VISTA survey has been labelled to show a selection of the many nebulae and clusters in this part of the sky. Credit: ESO/VVV Consortium, Acknowledgement: Ignacio Toledo, Martin Kornmesser
“Each star occupies a particular spot in this diagram at any moment during its lifetime,” said Dante Minniti, also from Pontificia Universidad Catolica de Chile, Chile, co-author of the study. “Where it falls depends on how bright it is and how hot it is. Since the new data gives us a snapshot of all the stars in one go, we can now make a census of all the stars in this part of the Milky Way.”
Getting such a detailed view of the central region of our galaxy is not an easy task.
“Observations of the bulge of the Milky Way are very hard because it is obscured by dust,” said Minniti. “To peer into the heart of the galaxy, we need to observe in infrared light, which is less affected by the dust.”
The team used ESO’s 4.1-metre Visible and Infrared Survey Telescope for Astronomy (VISTA), which has a wide field of view. This new image is just one of six public surveys carried out with VISTA.
“One of the other great things about the VVV survey is that it’s one of the ESO VISTA public surveys. This means that we’re making all the data publicly available through the ESO data archive, so we expect many other exciting results to come out of this great resource,” said Saito.