Answer to Question #65321 in Astronomy | Astrophysics for King

Question

Explain how sunspots survive for so long even though they are surrounded by hotter
matter. (A 5 marks answer is needed, so please don't give a brief answer)

Answer 1

In the center of the sunspot magnetic lines are directed almost perpendicular to the surface of the sun, and it approaches the edge of the spots they incline to the surface. However, the center spot magnetic lines are rather complicated and this is what prevents the development of granulation in the central regions of sunspots. Heated solar plasma consists of electrically charged particles that cannot move across the magnetic field lines straight. So powerful lines of the magnetic field at the center spot "pushed" back flow of hot plasma in the solar interior. Accordingly, the center spot you can see the lower layers are heated much less than in neighboring spot areas where well developed solar granulation. Therefore, the temperature at the center spot is below about 1000 or 1500 K surface temperature of the sun outside spots. According to the law of blackbody radiation flux from the center spot much smaller and the observer sees against the bright solar surface area that is two to four times darker. Closer to the edge spots magnetic field lines more streamlined and much inclined to the surface of the sun. Accordingly, it is possible movement of charged plasma that is made by convection from the interior of the sun, and the edge spots seen many threads of hot plasma directed along the magnetic field lines. Therefore spots on the edge of a substance heated than in the center, but still less than the outside spots.