Astronomers using the Robert C. Byrd Green Bank Telescope found the
negatively-charged form of octatetraynyl (C8H-) in a cold interstellar
cloud (middle left) and in the gaseous envelope surrounding an old,
evolved star (middle right). This is the largest negatively-charged
molecule yet found in space. The scientists believe it probably is
formed in steps, illustrated here, proceeding downward.
1. A molecule of C2H attaches to a molecule of C6H2, producing a
molecule of C8H2 and a hydrogen atom.
2. Radiation (squiggly line) breaks one hydrogen atom from the C8H2,
leaving C8H and a hydrogen atom.
3. Finally, an electron attaches itself to the C8H molecule, freeing a
burst of radiation (overall glow seen around the molecule) and leaving
the negatively-charged ion C8H-.
Credit: Bill Saxton, NRAO/AUI/NSF |
