Sun without sunspots In January 2018 the Sun had no sunspots for almost two weeks. This spotless period was a prelude to an approaching period of solar minimum in 2019, when the sun's activity was at the low end of its 11-year cycle. (more) How Hot Is the Sun? Ask the Chatbot a Question More Actions Share Share Share to social media Facebook X URL https://www.britannica.com/science/How-Hot-Is-the-Sun Feedback Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login). Feedback Type Select a type (Required) Factual Correction Spelling/Grammar Correction Link Correction Additional Information Other Your Feedback Submit Feedback Thank you for your feedback Our editors will review what you’ve submitted and determine whether to revise the article.

　　External Websites Ask the Chatbot a Question Written and fact-checked by The Editors of Encyclopaedia Britannica Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors. The Editors of Encyclopaedia Britannica Last Updated: Apr 2, 2025 • Article History Table of Contents Table of Contents Ask the Chatbot The surface of the Sun, known as the photosphere, reaches a temperature of about 5,800 kelvin (K; 10,000 degrees °F). This intense heat is what gives the Sun its glow, providing the warmth necessary for life on Earth. Deep within the Sun, the temperature in the core is 15 million kelvin (27 million °F). This is the powerhouse of the Sun, where nuclear fusion occurs, converting hydrogen into helium and releasing energy that makes its way to the surface as sunlight. It is this fusion process that keeps the Sun shining brightly. Interestingly, the Sun’s atmosphere also has some unexpected ...(100 of 159 words)

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