Astronomers have just created a massively detailed map of the Milky Way with 3.3. billion stars

In science fiction series like “Star Trek” and “star wars“, spaceships can fly around the galaxy thanks to detailed star maps in which they navigate faster than light ships. Here on Earth, we lack a comparable Google Maps version of our milky way galaxy – or at least we did.

Indeed, astronomers recently published a new, more detailed catalog of the Milky Way, called DECaPS2, which includes 3.32 billion celestial objects. Yes, you read that right: 3.32 billion. The new catalog is our galaxy’s largest roadmap to date, and sheds light on a better understanding of the intricacies and nuances of the galaxy we live in..

“It’s quite a technical feat. Imagine a group photo of over three billion people and each individual is recognizable!” said Debra Fischer, division director of astronomical sciences at the NSF (National Science Foundation) in a press release. “Astronomers will ponder this detailed portrait of more than three billion stars in the Milky Way for decades to come.”

Assembling the catalog was a huge and almost unthinkable undertaking, but thanks to the Cerro Tololo Inter-American Observatory (CTIO) – which is located at an altitude of 2,200 meters atop Cerro Tololo in Chile – the observatory’s unique vantage point has given astronomers the opportunity to capture Southern Hemisphere data in great detail. The new catalog now changes the perspective of scientists looking at the Milky Way since the data was collected in the Southern Hemisphere. The first set of data was published in 2017; in addition to the new data, astronomers believe the new catalog covers 6.5% of the night sky.

“One of the main reasons for the success of DECaPS2 is that we simply pointed to a region with extraordinarily high star density and were careful to identify sources that appear almost on top of each other,” said Andre Saydjarigraduate student at Harvard University, researcher at the University Astrophysics Center | Harvard and Smithsonian and lead author of the article, in a statement. “This allowed us to produce the largest catalog of its kind ever made from a single camera, in terms of the number of objects observed.”

“Astronomers rely on catalogs like these to extract and compress information from sky images about the galaxy we live in,” Saydjari said. “For example, we can learn about galactic structure, galactic dust distributions, and star formation.”

As for the Milky Way, most of the stars are located in its disk, which looks like the spot of light we see in photos of our galaxy from the edge (the only view we can see, thanks to its location directly inside one of the spiral arms of our galaxy). Although this spiral constitutes iconic photographs of our galaxy, it is more difficult to observe the galactic plane and to analyze the enormous number of stars. Indeed, with 100 billion stars in the Milky Way, clouds of dust have long prevented us from seeing the other side — until now.

“When combined with images of Pan-STARRS 1DECaPS2 completes a 360-degree panoramic view of the Milky Way’s disk and additionally reaches much fainter stars,” said Edward Schlafly, researcher at the AURA-run Space Telescope Science Institute and co-author of the paper, said in a statement, “With this new survey, we can map the three-dimensional structure of stars and dust in the Milky Way in unprecedented detail.”

In an email to Salon, Saydjari said the catalog would be an incredibly useful tool for astronomers.

“Astronomers rely on catalogs like these to extract and compress information from sky images about the galaxy we live in,” Saydjari said. “For example, we can learn about galactic structure, galactic dust distributions, and star formation.”

Saydjari added that he hopes people see that sometimes in astronomy the unthinkable is possible.

“I hope people will understand the amount of information available about our galaxy if we apply careful and rigorous statistical analyses,” Saydjari said. “Our program was relatively small in terms of telescope time, but we were able to make a big impact by tackling the difficult problem of crowded dense fields and spending a lot of time on careful software and statistical development.”

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