Their sizes vary over a wide range, with a few having been measured to be 50,000 km in diameter. A given sunspot can have a lifetime ranging from a few hours to a few months. Sunspots are regions with temperatures about 1500 K cooler than the photosphere, making them appear darker than their surroundings. Sunspots are temporary "blemishes" that appear on the Sun – they are darker than the surrounding regions and arise from intense magnetic activity. In addition, the photosphere is where sunspots form. Most of the Sun's radiation escapes from the photosphere and is detected as sunlight that we observe here on Earth. When we speak of the size of the Sun, we usually mean the size of the region surrounded by the photosphere. The Sun's atmosphere changes from transparent to opaque over just a few hundred kilometers, so the photosphere is about 500 kilometers thick. It's a little like watching someone walk into fog on a dreary morning - for a while they remain visible, but once they get deep enough into the fog, they disappear, and you can't see any deeper into the fog. The photosphere represents the depth at which we can see no deeper toward the core of the Sun. Instead, as you move from space toward the Sun's core, the gas gets denser and denser. Since the Sun is made up of hot gas, there isn't really a "surface" to it. The three parts of the atmosphere, from the surface of the Sun outward are the photosphere, chromosphere, and corona.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |