Researchers participating in the PHANGS collaboration, or Physics at High Angular resolution in Nearby Galaxies, are using Webb’s infrared capabilities to study 19 spiral galaxies. Megacluster of galaxies reveals its secrets in new Webb telescope image Stars releasing energy created giant bubbles of gas and dust, or luminescent cavities, that gather around the spiral arms of the galaxies, and sometimes these bubblelike features overlap to form shells and a structure similar to a spiderweb. Megacluster of galaxies reveals its secrets in new Webb telescope image Stars releasing energy created giant bubbles of gas and dust, or luminescent cavities, that gather around the spiral arms of the galaxies, and sometimes these bubblelike features overlap to form shells and a structure similar to a spiderweb