![]() Thickness ∼ 10⁴ km, Optically thin, so can only be seen directly during a solar eclipse. Light coming out of interior of sun will scatter ∼ 10 28 times (and take ∼10 6 years) : the surface is the position of last scatter, after which the light takes 7 minutes to reach earth. Photosphere is at a fairly uniform 5800 ☌.Solar Dynamics ObservatoryMany wavelengths simmultanously Channel nameįlaring regions (partial readoutpossible)įlaring regions(partial readout possible) This is in X-rays: note the hot X-rays come from the cool sunspots!Īnd this looks at the mag field: Dark is a N pole, light is a S poleĪnd this looks at the sun at 3 different temperatures: Red at 2 million, green at 1.5 million, and blue at 1 million degrees C. The Sun A prominence erupts from the surface of the sun: note there is very little material actually in theseīut we can look at the sun in different ways, so we can see how structure varies. SO (e.g.) we can pick out Hydrogen (H), which picks up the prominences very clearly What do we mean by taking the sun using the light of various atoms? This is what the solar spectrum looks like: dark lines correspond to various specific elements, and they have precisely known wavelengths.When we split the light up into a spectrum, we can see the sun in different ways Optically, we see a fairly bland surface, broken up by sunspots (and in this case, Mercury!)Ĭredit & Copyright: Rick Scott and Joe Orman The SunOnly star that we can see close up: fortunately it is a fairly typical. If your browser supports JavaScript, be sure it is enabled. This contrast makes sunspots stand out even more.Warning: jsMath requires JavaScript to process the mathematics on this page. ![]() At the same time, the hot gases blocked by these sunspots flow into the areas around them, making those areas even hotter and brighter than normal. Because sunspots are cooler than the rest of the sun's surface, they look darker. The bunched up spots - actually twists in the magnetic field lines - have so much magnetic power that they push back the hot gases beneath them and prevent the heat from rising directly to the surface. (Specifically, a point on the equator takes 25 Earth days to go around, while a point near one of the poles takes 36 days to complete its rotation.) Over time, all that messy and uneven movement twists and distorts the sun's main magnetic field in the same way that your bed sheets get wrinkled and bunched up when you toss and turn in your sleep. The interior and the exterior of the sun rotate separately the outside rotates more quickly at the equator than at the solar north and south poles. Sunspots occur because the sun isn't a hunk of rock like the Earth and the inner planets, but a ball of continually circulating hot gases that doesn't move in one piece. ![]() Sunspots are cooler because they're areas of intense magnetism - so intense that it inhibits the flow of hot gases from the sun's interior to its surface. That interior is surrounded by a larger, lighter area called the penumbra, which is about 500 degrees cooler than the rest of the sun. The dark interior of a sunspot, called the umbra, is about 1,600 degrees cooler than the rest of the sun's surface. Sunspots appear dark to us because they're cooler than the surrounding areas on the sun's visible surface, or photosphere, which has a temperature of about 10,000 degrees Fahrenheit (5,537.8 degrees Celsius).
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