Description: 恆星活動是用於描述磁場對恆星產生的各種影響的總稱。擁有強磁場的恆星表面會出現更多星斑。恆星的磁場也可能是其日冕加熱的來源，因此具有更強磁場的恆星通常會從日冕發出更多的X射線和紫外線輻射。在恆星光譜中也可以看到活動跡象，尤其是氫-α譜線的發射。這些效應呲合起來可以粗略地量化恆星的“活動”程度。質量較大的恆星（光譜類型為O型、B型和早期A型）通常活動較弱。隨著恆星質量的降低，活動逐漸增強，並在紅矮星（M型矮星）處達到峰值。年輕恆星比老年恆星更活躍。以太陽為例，其活動遵循一個11年的週期，期間黑子的數量會發生變化。

Related Terms:

• B 型星
• 冕
• 氫
• 紅矮星
• 太陽週期
• 光譜類型
• 太陽黑子
• 太陽黑子週期
• 紫外線（UV）
• M 型星
• 磁場
• O-type Star
• X射線

Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher
The translation of this term and its definition is still awaiting approval

This is an automated transliteration of the simplified Chinese translation of this term

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