SDO opens its eyes and sees our star like never before. Last week, NASA presented the first images and videos from its latest and greatest eye on the Sun: the Solar Dynamics Observatory.
SDO has been in the works for a long, long time, and I’ve been anxiously awaiting data from it for years… so of course I was away from my computer when the images were released. Still, it was worth a few extra days to see something as back-of-the-neck-hair-raising as this: Holy Haleakala! Click to emprominate. As if on cue, just days after SDO’s Atmospheric Imaging Assembly (AIA) was switched on, the Sun threw an epic fit, blasting out an arcing prominence perfectly positioned for us to see. To give you an idea of this, here’s a video made from images from AIA: Kaboom! I’ve been a big fan of the Solar and Heliospheric Observatory (SOHO) for a long time, and SDO is like the Son of SOHO. It also produces stunning full-Sun imagery: Of course, they’ll also have a pile of new mysteries to ponder as well. Credit: NASA/SDO/AIA, NASA/GSFC/SDO/AIA. Solar Dynamics Observatory. Solar and Heliospheric Observatory Homepage.
The boiling, erupting Sun. I keep thinking there’s nothing new under the Sun– or on it.
With SOHO, and SDO, and a thousand other telescopes pointed at it, it would take something pretty freaking cool to surprise me. Well then. Surprise! Holy solar retinopathy! That’s the Sun? Yup. In this picture you can see sunspots, giant convection cells, and the gas that follows magnetic loops piercing the Sun’s surface. The image he took is amazingly high-resolution! Wow, that’s breathtaking! In case you woke up today feeling important. I want to note that there’s a freaky optical illusion I get when I look at the top picture: if I look at one part, say the right hand edge, then quickly move my eye to the top, it appears as if the whole disk of the Sun shrinks for a moment.
Now, about that picture and how it works… The Sun’s surface puts out light at all wavelengths, but the surface isn’t solid. [Update: well, mea culpa: the next paragraph is wrong. Limb darkening. The limb-darkened Sun - An image of the Sun in visible light showing the limb darkening effect as a drop in intensity towards the edge or limb of the solar disk.
The image was taken during 2012 transit of Venus. Limb darkening is an optical effect seen in stars (including the Sun), where the center part of the disk appears brighter than the edge or limb of the image. Limb darkening occurs as the result of two effects:[clarification needed] The density of the star diminishes as the distance from the center increasesThe temperature of the star diminishes as the distance from the center increases.
An idealized case of limb darkening. The second effect is the fact that the effective temperature of the stellar atmosphere is (usually) decreasing for an increasing distance from the center of the star. Calculation of limb darkening[edit] Limb darkening geometry. For example, for a Lambertian radiator (no limb darkening) we will have all ak=0 except a0=1. (See Cox, 2000). Coronal mass ejection. This movie shows the particle flow around Earth as a coronal mass ejection strikes.
A coronal mass ejection (CME) is a massive burst of solar wind and magnetic fields rising above the solar corona or being released into space.[1] Coronal mass ejections are often associated with other forms of solar activity, most notably solar flares, but a causal relationship has not been established. Most ejections originate from active regions on the Sun's surface, such as groupings of sunspots associated with frequent flares. Near solar maxima, the Sun produces about three CMEs every day, whereas near solar minima, there is about one CME every five days.[2] Description[edit] Arcs rise above an active region on the surface of the Sun. Coronal mass ejections are associated with enormous changes and disturbances in the coronal magnetic field. Cause[edit] Recent scientific research[3][4] has shown that the phenomenon of magnetic reconnection is responsible for CME and solar flares.
Impact on Earth[edit]