A team of astronomers has produced a large catalog of the Milky Way’s layout. Considered the largest of its kind ever created, the new data set brings 3.32 billion objects in our galaxy observed by the Dark Energy camera, of the Inter-American Observatory of Cerro Tololo, formed by different telescopes installed in Chile.
- How are space photos taken?
- New map of the Milky Way appears to reveal ‘fossils’ of ancient spiral arms
Observing the billions of stars, star-forming regions, and towers of gas and dust is no easy task, yet researchers have managed to reveal a surprising amount of these objects in unprecedented detail. Over the course of two years of work on the Dark Energy Camera Plane Survey (DECaPS2), they achieved more than 21,400 individual exposures of more than 3 billion objects.
The result is the image below:
The DECaPS2 survey revealed observations of the plane of the Milky Way as seen in the southern hemisphere in visible light and near-infrared wavelengths. The first batch of data was published in 2017 and, with the most recent one, the program has now covered 6.5% of the night sky (equivalent to 13,000 times the angular area of the Moon at full phase).
“One of the main reasons for DECaPS2’s success is that we simply pointed to a region with an extraordinarily high density of stars, and we were careful to identify sources that appear to be almost one above the other,” said Andrew Saydjari, lead author of the paper that describes the observations. “This allowed us to produce the largest catalog ever made with a single camera”, he concluded.
Most of the Milky Way’s stars and dust reside in the disk, the bright streak that runs through the image you saw above. Of course, the stars and dust there make for amazing photos, but they are also a challenge for observations: the dust there absorbs starlight and “hides” the fainter ones, while the nebulae interfere with attempts to measure the brightness of objects. individual.
To complete, the amount of stars is such that they can overlap in the photo, making it even more difficult to differentiate them individually. By looking at this very complete region at near-infrared wavelengths, astronomers were able to see what’s beyond the dust absorbing the light. Furthermore, they used data processing techniques that allowed them to predict the background behind each star.
As a result, the final catalog of processed data is more accurate. “With this new survey, we can map the three-dimensional structure of stars and dust in the Milky Way in unprecedented detail,” added Edward Schlafly, co-author of the study. “This is a great technical feat: imagine a group photo of over three billion people — and every single individual is recognizable!” said Debra Fischer, director of astronomical sciences at NSF.
The paper describing the observations will be published in the Astrophysical Journal supplement and can be accessed in the arXiv repository, without peer review.
Source: arXiv; NOIRLab