Billions of celestial objects revealed in the gargantuan survey of the Milky Way

Astronomers have launched a gargantuan survey of the galactic plane of the Milky Way. The new dataset contains a staggering 3.32 billion celestial objects – arguably the largest such catalog by far. Data for this unusual survey were captured with the Dark Energy Camera, built by the US Department of Energy, at the NSF Cerro Tololo Inter-American Observatory in Chile, a program of the NOIRLab.

The Milky Way Galaxy contains hundreds of billions of stars, bright star regions, and dark clouds of dust and vapor. This imaging and catalog of objects is needed for Herculean study, but a recent release of astronomical data known as the second release of the Dark Energy Camera Plane Survey (DECaPS2) shows a staggering number of these objects in remarkable detail. The DECaPS2 survey, which took two years to complete and produced more than 10 terabytes of data from 21,400 individual eruptions, which are about 3.32 billion objects — arguably the largest such catalog compiled to date. Astronomers and the public can explore the dataset here.

This new collection was captured by the Dark Energy Camera (DECam) instrument on the Víctor M. Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory (CTIO), a part of NSF’s NOIRLab Program. The CTIO is a constellation of international astronomical telescopes erected on Cerro Tololo in Chile at an altitude of 2,200 meters (7,200 feet). CTIO’s lofty observation gives astrologers a unique view of the southern celestial hemisphere, which allowed them to capture the southern DEC in the Galactic plane in such a way.

DECaPS2 view of the plane of the Milky Way as seen from the southern sky at optical and near subsurface wavelengths. The first findings of DECaPS data were released in 2017, and, with the addition of new emission data, the survey now covers 6.5% of the night sky and spans a staggering 130 degrees in longitude. While it might sound modest, this equates to 13,000 times the angular distance of the full moon.

The DECaPS2 dataset is available to the entire scientific community and is hosted by the Astro Data Lab NOIRLab, which is part of the Community Science and Data Center. Interactive access to imaging with panning/zooming inside the car is available from the Ambassador Surveyor Inspector, World Telescope and Aladin.

Most of the stars and dust in the Milky Way are located in their orbit, a bright ball stretching across this image – in which the spiral arms lie. While this outpouring of stars and dust makes for beautiful images, it also makes observing the Galactic plane challenging. The dark threads of dust visible through this image of the stars absorb and completely blot out the fainter stars, and the diffuse light of the nebula interferes with attempts to measure the brightness of individual objects. Another challenge arises from the sheer number of stars that are included in the image and can make it difficult to distinguish individual stars from their neighbors.

Despite the challenges, astronauts ventured into the Galactic plane to gain a better understanding of our Milky Way. Observing near the broken waves, they could see much of the light being absorbed by the dust. The researchers also added electronic software that allowed them to better predict the career behind each star. This helped to reduce the effects of nebula and crowded star fields in such large astronomical images, so that the final catalog of processed data was more accurate.

“One of the main reasons for the success of DECaPS2 is that we simply showed it in a region with an extraordinarily high density of stars and were careful about identifying sources that appear close to each other,” said Andreas Saydjari, a graduate student. Harvard University, researcher at the Center for Astrophysics, Harvard & Smithsonian, and lead author of the paper. “And so it allowed us to produce the largest such catalog ever from a single camera, in terms of the number of objects observed.”

“Combined with images from Pan-STARRS 1, DECaPS2 completes a 360-degree panoramic view of the Milky Way and additionally covers much fainter stars,” said Edward Schlafly, researcher at the Space Telescope Science Institute and co-managed by AURA. -according to the published DECaPS2 paper Journal of Astrophysics Supplement. “With this new analysis, we describe the three-dimensional structure of Milky Way stars and dust in a unique way.”

“Since my work on the Sloan Digital Sky Survey two decades ago, I’ve been looking for a way to make better measurements over unstructured areas,” said Douglas Finkbeiner, a professor at the Center for Astrophysics, co-author of the paper and principal investigator behind the event. “He accomplished this work and more.”

“This is quite technical. Imagine a photo group of over three billion people and every single one is recognizable,” says Debra Fischer, director of the Astronomical Sciences division at NSF. “Astronomers have been evaluating this detailed portrait of more than three billion stars in the Milky Way for decades to come. This is a fantastic example of what companies through federal agencies can achieve.”