*銀河とは何か？
銀河は、恒星、ガス、塵、暗黒物質が重力によって一体となった巨大な天体構造です。宇宙には無数の銀河が存在し、それぞれが異なる形や特徴を持っています。
代表的な銀河の形状には、円盤状の「渦巻銀河」、不規則な形の「不規則銀河」、そして楕円形の「楕円銀河」があります。私たちの太陽系が属する「天の川銀河」は渦巻銀河で、約2,000億から4,000億個の恒星を含むとされています。
*What is a Galaxy?
A galaxy is a massive cosmic structure composed of stars, gas, dust, and dark matter held together by gravity. There are countless galaxies in the universe, each with its own distinct shape and characteristics.
The main types of galaxies include the "spiral galaxy," which has a disk-like structure; the "irregular galaxy," which has an irregular shape; and the "elliptical galaxy," which is more rounded. Our solar system is part of the "Milky Way galaxy," which is a spiral galaxy. The Milky Way contains roughly 200 to 400 billion stars. This vast and complex structure is just one example of the countless galaxies that populate the universe.
