When you think about how our own Earth formed billions of years ago, the picture is still a mystery filled with many many gaps. Astronomers know that stars are born in giant clouds of gas and dust, and that planets come from the swirling disks left behind.
However, looking deep into these swirling cradles of planet formation has always been tricky. Dust hides what lies inside, and even the most powerful telescopes until recently struggled to uncover the fine details.
Now, NASA’s James Webb Space Telescope (JWST), working together with the Hubble Space Telescope, has provided a breathtaking new look at IRAS 04302+2247, also called the Butterfly Star.
About 525 light-years away in the Taurus star-forming region, this young protostar is surrounded by a massive protoplanetary disk stretching 65 billion kilometers across, several times wider than our solar system.
Webb’s detailed images of such disks are helping researchers understand how dust evolves into planets, giving them valuable insights about what happened 4.5 billion years ago when our own solar system took shape.
Capturing the butterfly star
To study this stellar nursery, astronomers used Webb’s Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI), combined with Hubble’s optical observations. Together, they captured IRAS 04302’s disk in extraordinary detail.
The disk is oriented edge-on from our point of view, which means Webb sees it as a thin dark band blocking the bright light of the growing star at the center.
Instead of rings and spirals (which we notice when disks are viewed face-on), this angle reveals the disk’s vertical structure, its thickness, and how dust grains are settling toward the midplane. This settling process is critical because it allows grains to clump together and grow into the building blocks of planets.
“The thickness of the disc is a measure of how efficient this process has been,” the ESA team notes.
What makes the Butterfly Star so striking are the two luminous wings of nebulous gas and dust that appear on either side of the disk. These reflection nebulae shine because light from the protostar bounces off them, creating the butterfly-like shape.
The dark streak across the middle is actually the dense lane of dusty gas that cocoons the young star, making it easier for Webb to detect the faint features around it. Hubble, on its part, highlights clumps and streaks near the dust lane, showing that the star is still actively feeding on material from its surroundings while also releasing jets and outflows.
“Together, these powerful facilities paint a fascinating multiwavelength portrait of a planetary birthplace,” the ESA team added. They have declared the new view of the IRAS 04302+2247 Picture of the Month.
Protoplanetary disks are of great significance
The project is a part of Webb’s GO program #2562, which focuses on four protoplanetary disks that happen to be aligned edge-on, providing a unique chance to measure how efficiently dust is growing and settling in these environments.
Webb’s sharp infrared vision is crucial here, as it reveals the distribution of very small dust grains and traces light scattering far away from the disk. By mapping the Butterfly Star’s protoplanetary disk in such detail, astronomers are piecing together one of the most important puzzles in planetary science. i.e., how simple dust and gas turn into planets.
Understanding this process doesn’t just explain our own origins, it helps scientists predict how common Earth-like worlds might be around other stars.
Moreover, this achievement also highlights the importance of looking at disks from multiple angles. While face-on views show structures like rings and gaps, the edge-on views expose how dust settles vertically. Both perspectives are needed to build a complete picture.
The next goal of the researchers is to expand their survey to more protoplanetary disks, using Webb’s sensitivity to track dust growth at different stages.