基礎的な物理学と数学的概念を用いて太陽の物理特性、構造、形成、未来の進化などの知見をまとめた一冊です。太陽に黒点が出るのはなぜなのか、表面で爆発現象（太陽フレア）が起きるのはなぜなのか。太陽の複雑な特性は、常に変化し続ける太陽の磁気と関係しています。これがありふれた星を、惑星間空間に可変型放射線や高エネルギー粒子、磁気を放出させる「マシン」へ変えるのです。太陽について解明できれば天文学や基本物理学上の重要な発見にもつながるため、多くの研究者がその謎に挑んでいます。
　　

• Explains how the Sun works including its physics, and structure, origins, and future evolution
• Considers the importance of the Sun for life on Earth, and its impact on our climate
• Shows how studying the Sun has led to remarkable discoveries in astronomy and basic physics
• Discusses what we still have yet to discover about our nearest star

    
The Sun, as our nearest star, is of enormous importance for life on Earth - providing the warm radiation and light which allowed complex life to evolve. The Sun plays a key role in influencing our climate, whilst solar storms and high-energy events can threaten our communication infrastructure and satellites.
                
This Very Short Introduction explores what we know about the Sun, its physics, its structure, origins, and future evolution. Philip Judge explains some of the remaining puzzles about the Sun that still confound us, using elementary physics, and mathematical concepts. Why does the Sun form spots? Why does it flare? As he shows, these and other nagging difficulties relate to the Sun's continually variable magnetism, which converts an otherwise dull star into a machine for flooding interplanetary space with variable radiation, high-energy particles and magnetic ejections. Throughout, Judge highlights the many reasons that the Sun is important, and why scientists engage in solar research.