James Webb Captures a Protostar in a Fiery Hourglass
The very young star is a window into our own solar system’s past
Looking at the James Webb Space Telescope’s latest showstopping image of a faraway protostar is like peering back to a time when the sun and planets of our solar system were just beginning to form.
The dazzling new photo, which NASA shared Wednesday, shows the fiery hourglass shape made by a star in its infancy. Webb snapped the portrait using its near-infrared camera (NIRCam), which can capture scenes in the wavelength range of 0.6 to 5 microns—beyond what’s detectable in the visible spectrum.
The protostar and its dark cloud, both named L1527, are located in the Taurus star-forming region some 460 light-years from Earth. Scientists estimate L1527 to be around 100,000 years old, which is relatively young in star terms—this hot, bright celestial body still has a long way to go before it becomes a full-grown star. (Our sun, meanwhile, is around 4.6 billion years old.) Researchers consider L1527 a class 0 protostar, which represents the earliest stage of star formation.
Eventually, L1527 will create its own energy via the nuclear fusion of hydrogen, which is a hallmark of stars. But for the time being, it’s still an unstable, puffy bundle of gas that’s continuing to gather mass. For comparison, L1527 is around 20 to 40 percent the mass of the sun.
The protostar, though not visible in Webb’s image, is situated at the center, within the skinny neck of the hourglass shape. The dark line running through the middle is a dense swath of material called an accretion or protoplanetary disk, which formed as a result of the young star gathering mass and drawing dense dust and gas toward itself.
As the spiraling accretion disk feeds material to L1527, the protostar will gain even more mass, which will cause its core to compress and heat up. Given enough time, the temperature will rise so much that nuclear fusion can begin.
The disk is about the size of our solar system—but the similarities don’t stop there. Some of the dust and gas is likely to start clumping together, and those clumps could eventually become planets. As such, L1527 may one day become its own solar system.
The orange and blue clouds in the photo—the upper and lower halves of the hourglass shape—are regions where material blasted out from the star has collided with surrounding matter. These areas mark the boundaries of cavities cleared by the ejections, which scientists also refer to as “stellar burps.”
“To the top and the bottom, you see light from the protostar illuminating the cavities within the surrounding outflows of gas and dust from this object,” said Mark Clampin, the astrophysics division director for NASA’s Science Mission Directorate, during a House subcommittee meeting this week, as reported by Gizmodo’s Isaac Schultz.
As the protostar shoots out material, it also shocks filaments of molecular hydrogen, preventing other new stars from forming in the region. This means the protostar can keep most of the surrounding matter for itself and doesn’t have to share.
Layers of dust between Webb and the protostar give the regions their different colors. A thin layer of dust allows plenty of blue light to escape, creating the bluer areas. A thicker layer of dust, by contrast, doesn’t let as much blue light through, thus giving rise to the more orange-colored pockets.
The gorgeous snapshot of L1527 is just one of the many dispatches Webb has sent back to scientists since launching in December 2021. A collaboration between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA), the high-tech telescope has also revealed distant galaxies, exposed Neptune’s hard-to-see rings and given us new views of old favorites, like the Pillars of Creation, to name a few.