NASAさんのインスタグラム写真 - (NASAInstagram)「First discovered in 1798 by German-English astronomer William Herschel, NGC 613 is a galaxy that lies in the southern constellation of Sculptor, 67 million light-years away. Featured here in an image from @NASAHubble, NGC 613 is a lovely example of a barred spiral galaxy. It is easily distinguishable as such because of its well-defined central bar and long arms, which spiral loosely around its nucleus. As revealed by surveys, about two-thirds of spiral galaxies, including our own Milky Way galaxy, contain a bar. Recent studies have shown that bars are more common in galaxies than they were in the past, giving us important clues about galaxy formation and evolution. Image credit: ESA/Hubble & NASA, G. Folatelli」1月17日 2時02分