Scientists create Milky Way stars’ new map on which there are 3.3 billion objects

Thanks to the new DECaPS2 project, astronomers have begun to learn much more about the Milky Way galaxy. Scientists have published the galaxy’s new star catalog that describes an unprecedented number—3.32 billion—of objects. This is the largest of such star catalogs—albeit it describes only a small fraction of objects hidden in the universe.

The Dark Energy Camera (DECam) is used in this project. It is a 520-megapixel video camera mounted on the 4-meter Víctor M. Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile.

As Universetoday.com reports, this camera was originally created specifically for the Dark Energy Survey project, which was completed in 2019. In parallel, the camera was adapted for the new project, and the first DECaPS2 data was published back in 2017. The latest update covers 6.5% of the sky and 130 degrees—which is 13,000 more than the full Moon.

According to Andrew Saijari, the leader of the new study, the success of DECaPS2 is not the long duration of the project, but solving the difficult problem of studying dense stellar regions located in the galactic plane.

In the course of their work, the scientists directed the aforesaid telescope to a part of the sky with a very high density of stars and carefully separated the light sources from each other, which, due to their large number, were literally arranged on top of each other.

The DECam camera has become an ideal tool for studying the most densely populated regions of this galaxy. It operates in the near-infrared spectrum, which enables it to "see" through clouds of dust and gas that absorb visible light.

The aforementioned website notes that by combining the obtained data with images taken by the Pan-STARRS 1 observatory, a three-dimensional map of the Milky Way disk can be prepared. Data on the structure and arrangement of stars and interstellar space had not been available before.