NASAさんのインスタグラム写真 - (NASAInstagram)「🌀This spiral galaxy's galactic bulge is not the result of too many holiday cookies.🍪 This galaxy was observed for a Hubble study on galactic bulges, the bright round central regions of spiral galaxies. Spiral galaxies like IC 2051 are shaped a bit like flying saucers when seen from the side; they comprise a thin, flat disk, with a bulky bulge of stars in the center that extends above and below the disk. These bulges are thought to play a key role in how galaxies evolve, and to influence the growth of the supermassive black holes lurking at the centers of most spirals. While more observations are needed in this area, studies suggest that some, or even most, galactic bulges may be complex composite structures rather than simple ones, with a mix of spherical, disk-like, or boxy components, potentially leading to a wide array of bulge forms in the universe. Credit: ESA/Hubble & NASA, P. Erwin et al. #nasagoddard #space #science #galaxy」12月21日 5時58分