Star Cluster $31.40 Priority Mail Express Stamps, 2025 Sheet – Priority Mail Express Postage

Captured in vivid detail by NASA’s James Webb Space Telescope (JWST) in 2022, star cluster IC 348 provides clues to the origins of stars and planetary systems. The U.S. Postal Service celebrates our continued exploration of deep space with a captivating new Priority Mail Express® stamp.

Within the image, stellar material, captured in infrared light by JWST’s filters, cascades like billowing pink, purple, and white curtains while reflecting the light from the cluster’s stars — this is known as a reflection nebula.

Hidden within the enormous cloud of celestial dust are tiny, free-floating brown dwarfs — objects too small to be stars but larger than most planets. Each of the three brown dwarfs is less than eight times the mass of Jupiter. The smallest has just three to four times Jupiter’s mass, a tiny celestial body among the expanse of space. Because this star cluster is young — only about 5 million years old — the brown dwarfs appear relatively bright in infrared light, glowing from the heat of their formation.