1. SOLAR FLARES Marina Rodríguez Baras 1

2. Solar activity Why do we study it? Close study of the internal processes of a star. Preventing the effects on the Earth. NASA/Steele Hill 2

3. Solar flare: definition Definition: Big explosions on the surface of the sun. Effect: They heat material and release energy. Place: Usually near sunspots. TRACE satellite. September 5, 2005 3

4. Example: 13 Dec 2006 (Hinode) Hinode's Solar Optical Telescope (SOT) on Dec. 13, 2006 4

5. Energy released Electromagnetic radiation: Across the whole spectrum. Flares classified by their X-ray flux. Each class has a tenth of the energy of the superior one. ClassPeak flux [w/m 2 ] in 1-8 Å X>10 -4 M10 -5 to 10 -4 C10 -6 to 10 -5 B10 -7 to 10 -6 A10 -8 to 10 -7 5

6. Energy released Each category has nine subdivisions (X1- X9, M1-M9…) NOAA satellites, July 2000 6

7. Origin: magnetic shear Origin in the structure of the magnetic field around sunspots. Magnetic field lines twisted and sheared. Reconnection of lines provoke release of energy. NOAA Active Region AR6659, June 10, 1991 7

8. Origin: magnetic shear Hinode's Solar Optical Telescope (SOT), 10th-14th December 2006 8

9. Reconnection of lines Tension accumulated causes a reconnection of the lines of magnetic field. The reconnection implies releasing a high amount of energy. Figure of Gordon D. Holman (NASA) 9

10. Reconnection of lines Magnetic reconnectionReconnection in 3D Figures of Gordon D. Holman (NASA) 10

11. Global events K Schrijver & A (NASA) (solar flare 1st August 2010) 11

12. Global events Solar Dynamics Observatory (1st August 2010) 12

13. It is waiting for us! Thank you! 13

14. 14 Solar Dynamics Observatory (NASA), April 19 2010