DARK SOLAR FILAMENT: Most solar flares come from sunspots. The next big explosion, however, could come from a different source: A huge magnetic filament is hanging over the surface of the sun, and it could erupt at any moment. Sergio Castillo photographed the structure from his backyard observatory in Corona, CA:
“This dark filament wish is really easy to spot using a backyard solar telescope,” says Castillo. “Many amateur astronomers are photographing it.”
The structure is, essentially, a tendril of plasma more than 400,000 km long held suspended above the surface of the sun by magnetic forces. Its scale is nicely illustrated in this diagram prepared by Spaceweather.com reader Sefano Sello of Pisa, Italy. If the filement were peeled off the sun and stretched out, it would easily reach from Earth to the Moon. It could also be wrapped around the circumference of giant Jupiter many times over.
If the filament becomes unstable and erupts, it could hurl parts of itself into space. Pieces of the filament falling back to the solar surface would explode upon impact, creating one or more Hyder flares. Astronomers with backyard solar telescopes are encouraged to monitor the structure as it turns toward Earth. A photogenic explosion may be in the offing.