The Orion Nebula, 1350 light-years from Earth, appears to the naked eye as a fuzzy star in the sword of Orion. The nebula is spawning stars large and small, so observers often study it to learn about star birth. Now, however, astronomers say that at least 10% to 20% of the thousands of stars ascribed to the 1-million-year-old Orion Nebula cluster actually belong to the Iota Orionis cluster, which lies just in front of the Orion Nebula and is four to five times older. The finding means astronomers must revisit earlier conclusions about young stars, the researchers write in a future issue of Astronomy & Astrophysics. For example, planet-forming disks tend to disperse with time, so if some of the Orion stars are older than thought, a greater percentage of the youngest ones sport protoplanetary disks. And that means there could be an even greater abundance of strange new worlds for astronomers to discover.
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