| Abstract from DBPedia | A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in about two thirds of all spiral galaxies, and generally affect both the motions of stars and interstellar gas within spiral galaxies and can affect spiral arms as well. The Milky Way Galaxy, where the Solar System is located, is classified as a barred spiral galaxy. Edwin Hubble classified spiral galaxies of this type as "SB" (spiral, barred) in his Hubble sequence and arranged them into sub-categories based on how open the arms of the spiral are. SBa types feature tightly bound arms, while SBc types are at the other extreme and have loosely bound arms. SBb-type galaxies lie in between the two. SB0 is a barred lenticular galaxy. A new type, SBm, was subsequently created to describe somewhat irregular barred spirals, such as the Magellanic Clouds, which were once classified as irregular galaxies, but have since been found to contain barred spiral structures. Among other types in Hubble's classifications for the galaxies are the spiral galaxy, elliptical galaxy and irregular galaxy.棒渦巻銀河（ぼううずまきぎんが、barred spiral galaxy）は銀河のハッブル分類における種類の一つである。渦巻銀河と全く同じ特徴（バルジ即ち中心核部分は老齢の赤っぽい星が多い。腕の部分は青い若い星が多く見られ、星間物質を豊富に含む、等）を持つが、銀河中心のバルジを貫くような配置の棒状構造をディスク（中心核と腕を含む銀河円盤）内に持ち、渦状腕がこの棒構造の両端から伸びている点が通常の渦巻銀河と異なる。 全天で観測される渦巻銀河のうち、約半数が棒渦巻銀河である。我々の銀河系（天の川銀河）も棒渦巻銀河であると考えられている。 (Source: http://dbpedia.org/resource/Barred_spiral_galaxy) |
