DECam Captures 570-Megapixel View of Corona Australis Cloud 430 Light-Years Away

Q: What violent cosmic collisions are hidden inside the freezing dust of the Corona Australis cloud?

The “violent cosmic collisions” inside the Corona Australis cloud are not galaxy smashups but much smaller, high-energy impacts tied to newborn stars: jets and outflows from protostars slamming into surrounding gas and dust, creating Herbig-Haro objects. In this cloud’s dense Coronet star-forming region, very young stars are still accreting material while also ejecting narrow, fast streams of ionized gas. When those jets hit the cold molecular cloud at speeds of hundreds of kilometers per second, they generate shock fronts that heat and excite the gas. Those shocks are what astronomers identify as Herbig-Haro objects. One of the clearest examples in Corona Australis is HH100, highlighted in background material linked to the new DECam image. It marks a place where matter launched by a young star collides with nearby gas, briefly lighting up an otherwise dark, frozen environment. These features are transient on astronomical timescales, lasting only tens of thousands of years. The new image also points to a broader truth about the cloud: beneath dust at roughly 13–22 kelvin, star birth is not calm. Gravity is collapsing gas into protostars, while those same forming stars blast material back out, carving cavities, driving shocks, and reshaping the nebula around NGC 6729, NGC 6726, NGC 6727, and IC 4812. So the hidden violence is the collision of protostellar jets and winds with the cloud itself—the shock-driven activity that reveals stars being born.

Q: How does a single telescope image capture both the universe's oldest stars and its newest fiery creations simultaneously?

It can because the image is a line-of-sight snapshot of a crowded patch of sky, not a picture of objects all at the same distance or age. In the same DECam field, the Corona Australis Molecular Cloud lies only about 430 light-years away and is actively making stars. Its gas and dust are so cold that they collapse into protostars, while young stars such as the binary R Coronae Australis light up the cloud. The blue parts of NGC 6729 are reflection nebulae, where dust scatters starlight, and the orange glow is emission nebulae, where ultraviolet radiation from newborn stars ionizes gas. Those are the image’s “newest fiery creations.” At the upper right, however, sits NGC 6723, a globular cluster roughly 27,000 to 29,000 light-years away. It only appears close to the cloud because both fall within the camera’s wide field of view. In reality, it is a separate background object packed with hundreds of thousands of stars, many more than 10 billion years old and some nearly as old as the universe. What makes this possible technically is DECam’s unusual combination of breadth and detail: a 570-megapixel camera with 74 detectors and a nearly 1-meter lens on the Blanco 4-meter telescope. That allows astronomers to record a nearby stellar nursery and a far more distant ancient cluster in one exposure, turning a single image into a visual timeline of stellar life—from birth to some of the Milky Way’s oldest surviving stars.

Q: Why is this freezing, star-birthing molecular cloud suddenly accelerating away from our galaxy's plane?

The most likely reason is past supernova feedback: astronomers now think shock waves from at least two nearby ancient supernova explosions pushed the Corona Australis star-forming complex and gave it enough momentum to accelerate away from the Milky Way’s plane. That idea comes from a 2023 Astronomy & Astrophysics study, which found the Corona Australis complex is not static but moving away from the Galactic plane with measurable acceleration. The cloud itself is extremely cold—about 13 to 22 kelvin, or roughly minus 260 Celsius—which is why it can still collapse into new stars. Its frigid temperature is not causing the motion; the movement is a large-scale dynamical effect, likely imposed from outside. Follow-up work in 2025 added more detail. Researchers split the complex into a younger “CrA-Main” and an older “CrA-North” subregion and found they were once closer together but are now drifting apart. That supports a picture of the cloud having been disturbed by energetic events, rather than simply evolving quietly in place. In practical terms, Corona Australis appears to be part of a broader story seen in nearby interstellar clouds: supernovae can compress gas enough to trigger star formation while also shoving whole cloud complexes through space. So the same violent events that may have helped shape this stellar nursery may also be driving its unusual upward escape from the Galaxy’s disk.

1 articles · Updated · Livescience.com · Aug 23

A newly shared DECam image reveals the Corona Australis Molecular Cloud in striking detail, combining swirling nebulae, dark dust lanes and bright star clusters in one wide field.
430 light-years from Earth, the cloud is among the nearest active star-forming regions; temperatures near minus 440 F let dense gas and dust collapse into new stars.
NGC 6729 glows on the image's left, where reflected blue light and orange ionized gas surround R Coronae Australis, a binary system with a 43-to-47-year orbit.
NGC 6723 appears in the upper right about 29,000 light-years away, packing hundreds of thousands of ancient stars and hinting at a complex evolutionary history.
The image also showcases DECam's reach: the 570-megapixel instrument on Chile's Blanco 4-meter telescope uses 74 detectors and a 1-meter lens to survey wide southern skies.

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Livescience.com1d ago

Dark Energy Camera Captures Corona Australis Molecular Cloud Image

What violent cosmic collisions are hidden inside the freezing dust of the Corona Australis cloud?

How does a single telescope image capture both the universe's oldest stars and its newest fiery creations simultaneously?

Why is this freezing, star-birthing molecular cloud suddenly accelerating away from our galaxy's plane?

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1 total

Livescience.com1d ago

Dark Energy Camera Captures Corona Australis Molecular Cloud Image

DECam Captures 570-Megapixel View of Corona Australis Cloud 430 Light-Years Away

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