If you log on to ScienceAlert regularly, you’ll be familiar with some stunning space images, but one recently released image has to be one of the best yet: 2 years in the making, 10 terabytes of data, 21,400 individual exposures. combined, and a final image showing a whopping 3.32 billion celestial objects.
We have the Dark Energy Camera (DECam) to thank for this beautiful shot from space, which is part of the 4-meter Víctor M. Blanco Telescope at the Cerro Tololo Inter-American Observatory (CTIO), some 2,200 meters (7 218 feet) above sea level in Chile.
The image was released as part of the Dark Energy Camera Plane Survey (DECaPS2), and it gives us more detail than ever before about this part of space – it’s about 6.5% of the entire sky nocturnal, focusing on the galactic plane of the Milky Way where most of the galaxy’s mass is located.
“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,” explains the astronomer Andrew Saydjari of Harvard University in Massachusetts.
“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.”
This high density comes with a few problems: the vast expanses of space dust and the glow of brighter stars can completely block light from darker objects. By measuring both optical and near-infrared wavelengths, DECam overcomes these problems.
The team also used a special data-processing technique to better estimate what each star’s background should look like, allowing more stars to be observed with greater clarity and improving the overall accuracy of the image.
When combined with other surveys of the sky – such as the Pan-STARRS project – the latest telescope technology gives us an unprecedented look at the Universe outside our planet, which of course gives us clues as to how it came into existence.
“When combined with images from Pan-STARRS 1, DECaPS2 completes a 360-degree panoramic view of the Milky Way’s disk and additionally reaches much fainter stars,” says astronomer Edward Schlafly of Space Telescope Science. Institute of Maryland.
“With this new survey, we can map the three-dimensional structure of stars and dust in the Milky Way in unprecedented detail.”
The results are simply fantastic and well worth the two year wait. Data collected through the survey is freely available to other researchers and the general public.
DECam was originally built to investigate dark energy and to better understand this mysterious force that is believed to drive the Universe. It continues to produce incredibly detailed images of deep space, and there will be many more to come.
“It’s quite a technical feat,” says astronomer Debra Fischer of the National Science Foundation (NSF) in the US, who was not directly involved in the research. “Imagine a group photo of over three billion people, and each individual is recognizable!”
“Astronomers will ponder this detailed portrait of more than three billion stars in the Milky Way for decades to come. It’s a fantastic example of what partnerships between federal agencies can achieve.”
The research was published in the Astrophysical Journal Supplement Series.