A new survey of the Milky Way has been released containing more than 3 billion objects, making it one of the largest astronomical catalogs ever made. The second data release from the Dark Energy Camera Plane Survey, or DECaPS2, focuses on the galactic plane, which is the view across the galaxy’s disk where most of the stars reside, covering 6.5% of the night sky.
The dataset is available to astronomers for their research, but can also be viewed online by the public in a web browser. The Legacy Survey Viewer shows a variety of different survey images – you can select DECaPS2 images in the top right box to view the new data and use the top left slider to zoom in and out.
The galactic plane is difficult to image because there are so many stars that can overlap as seen from Earth, and because there is a lot of dust, which you can see as dark swirls in the image above, that can obscure stars behind. So the study looked at near-infrared wavelengths, which can see through the dust for a better view, to build a 3D view of the galaxy.
“One of the main reasons for the success of DECaPS2 is that we simply pointed to a region with an exceptionally high density of stars and were careful to identify sources that appear almost on top of each other,” said lead author of an article on the survey, Andrew Saydjari from the Center for Astrophysics | Harvard & Smithsonian, in a statement. “In this way, we were able to create the largest single-camera catalog of its kind in terms of the number of objects observed.”
The total number of objects visible in the dataset is 3.32 billion and is the result of 10 terabytes of data from 21,400 individual images taken with the Dark Energy Camera in Chile.
“It’s quite a technical feat. Imagine a group photo of over three billion people and everyone is recognizable!” said Debra Fischer of the National Science Foundation, which funded the Dark Energy Camera. “Astronomers will be poring over this detailed portrait of more than three billion stars in the Milky Way for decades to come. This is a fantastic example of what federal agency partnerships can achieve.”