Este fue
tu cielo.

Old Planetary Dust Disks Found by SST

The Spitzer Space Telescope has found that some older stars are surrounded by dust disks. Conventional wisdom suggested that young stars, about a million years old, have large dust disks, while older stars, between 10 and 100 million years old, have none. Spitzer's observations challenge this, showing that dust disks can persist longer than expected around these older stars.