ANALISIS EVOLUSI KELOMPOK BINTIK MATAHARI DAN PROBABILITAS LEDAKAN MATAHARI KELAS X BERDASARKAN NILAI FRAKTAL KELOMPOK BINTIK MATAHARI AR12192 DAN AR12209

• Main Author: Ersasiwi Aziza, Shafira
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/57572
• Institution: Institut Teknologi Bandung

Solar energetic activity, such as solar flare, was produced by the magnetic field on individual sunspots or sunspot groups. The magnetic field on the sunspots is implied from the total area of the spots. Additionally, magnetism can be analyzed using fractal dimension (FD). The evolution of the sunspot groups and the probability of the X-class solar flares would be analyzed by measuring the total area and FD value of the sunspot group throughout its lifetime. The large sunspot groups have a long lifetime evolution and triggered lots of energetic solar flares. AR12192 was the largest sunspot group on 24 solar cycles that reemerged as the recurrent sunspots, AR12209. The analysis of the total area and FD value was conducted in heliographic longitude ?~60, so the projection effect of the images could be minimized. There were 31 images of AR12192 and 31 images of AR12209 taken from IAS SDO with HMI Continuum filter. The evolution of sunspot groups can be analyzed from the relation of the total area to time and the relation of FD value to time during the lifetime. Whereas, the probability of X-class flares is analyzed by observing the changes before, during, and after it. Based on the research, the evolution of sunspot groups was initialized with the increasing total area until it reached the maximum. Afterward, the total area was decreasing at the end. It's valid for AR12192, AR12209, and the total evolution of AR12192. Nevertheless, the FD value of AR12192 was increasing and the range 1,31 – 1,52, but the FD value of AR12209 was decreasing and the range 1,12 – 1,35, which indicates that the level complexity of AR12192 is greater than the AR12209. Thus, the total evolution of AR12192 was increasing in the beginning and decreasing at the end. The studied on X-class probability was found that it occurred when the total area was >~16×108 km2. The total areas increased before until start of flares and decreased during flares until the end of the flares. Furthermore, flares occurred when the FD value was >~1.42. There were increased before the flare then decreased after it.