{
  "id": 15059953,
  "title": "New 3D model reveals how shadows reshape chemistry in stellar nurseries",
  "url": "https://urgent.news/2026/10/16/new-3d-model-reveals-how-shadows-reshape-chemistry-in-stellar",
  "topic": "science",
  "section": "Science",
  "published": "2026-10-16T22:40:04.000Z",
  "source": {
    "name": "Phys.org",
    "slug": "phys-org",
    "url": "https://phys.org/news/2026-10-3d-reveals-shadows-reshape-chemistry.html"
  },
  "original_language": "en",
  "account": "A new high-resolution 3D model has revealed how shadows cast by dense gas in stellar nurseries reshape the chemistry within these cosmic nurseries, influencing the infrared light observed by telescopes like the James Webb Space Telescope. Led by Dr. Brandt Gaches from the University of Duisburg-Essen, an international team developed the model, which was published in Astronomy & Astrophysics.\n\nStars form within vast clouds of cold gas and dust. When massive young stars emerge and begin to shine, their intense ultraviolet light heats the surrounding gas, breaks apart molecules, and triggers a cascade of chemical reactions in the outer layers of the clouds, known as photodissociation or photon-dominated regions. These regions provide vital clues about star formation and gas recycling throughout the galaxy and across the universe's history.\n\nThe Orion Bar, located about 1,350 light-years from Earth, serves as an ideal natural laboratory for studying these processes. Its nearly edge-on orientation allows astronomers to observe its different chemical layers in exceptional detail. While previous models often represented the Orion Bar as a series of one-dimensional layers, the new high-resolution 3D model captures its complex, irregular structure.\n\nThe model reveals how dense regions of gas cast shadows, creating shielded pockets in which the chemistry develops differently. These shadows alter the behavior of molecular hydrogen, the most abundant molecule in the universe, and lead to the recombination of ionized carbon. This results in distinct chemical transitions, such as the change from atomic to molecular hydrogen, which leave a clear signature in the infrared to radio wavelengths of light observed from these regions.\n\nThe intricate three-dimensional structure of the Orion Bar also explains the arcs and filaments observed by the James Webb Space Telescope (JWST). By simulating the complex 3D structure, the model allows researchers to create realistic images of how such regions should appear to JWST, facilitating comparisons with the telescope's actual observations. This enables scientists to study how the three-dimensional structure of stellar nurseries shapes their chemistry, a phenomenon that simpler one-dimensional models cannot capture.",
  "summary": "How do young stars reshape the clouds from which they are born? A new high-resolution 3D model developed by an international team led by Dr Brandt Gaches from the University of Duisburg-Essen shows how the uneven structure of stellar nurseries creates shadows that alter their chemistry and influence the infrared emission observed by the James Webb Space Telescope. The model has now been published…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}