First ‘bone’ of the Milky Way identified
Astronomers have identified a new structure in the Milky Way: a long tendril of dust and gas that they are calling a “bone.” “This is the first time we’ve seen such a delicate piece of the galactic skeleton,” says the lead author Alyssa Goodman of the Harvard-Smithsonian Center for Astrophysics (CfA). Goodman presented the discovery Jan. 8 in a press conference at a meeting of the American Astronomical Society in Long Beach, Calif. Our Milky Way is a spiral galaxy — a pinwheel-shaped collection of stars, gas, and dust. It has a central bar and two major spiral arms that wrap around its disk. Because we view the Milky Way from the inside, its exact structure is difficult to determine. Internal bones, or endoskeletons, have been seen in other spiral galaxies. Observations, especially at infrared wavelengths of light, have found long, skinny features jutting between galaxies’ spiral arms. These relatively straight structures are...