noun
second magnitude star
Astronomical term for a star with an apparent magnitude between 1.5 and 2.5. Used in both scientific and casual stargazing contexts.
北斗七星のうち、二等星はどれですか。
Which of the Big Dipper stars is a second magnitude star?
今夜は二等星までよく見える。
Tonight we can see stars down to second magnitude clearly.
Compound of 二 (ni, 'two'), 等 (tō, 'class, rank'), and 星 (sei, 'star'). The term follows the standard pattern for stellar magnitude classification.