#TITLE_ALTERNATIVE#

• Main Author: YUS'AN (NIM : 10310008); Pembimbing : Dr. Dhani Herdiwijaya, UBAYDILLAH
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20587
• Institution: Institut Teknologi Bandung

The sun is the biggest source of energy for the Earth. All activities occur on the sun will affect human activities. Solar cycle can be determined through the sun 11 years cycle (average). Those cycle shows the magnetic activity of the Sun, from the minimum to the maximum and then back to minimum, marked by the occurrence of Plage and Sunspot. Plage is a bright spot, generally located around the black spots (sunspots). Measuring the Plage and Sunspot can be used as a direct indicator for solar activity. <br /> <br /> This study aims to determine the evolution of Plage and Sunspot. Observations of solar activity using a filter Calcium II - K (Ca II - K), because it is sensitive to high magnetic activity in the chromosphere of the Sun. This filter is mounted on the solar telescope, located at Bosscha Observatory. Telescope diameter is 60 mm (f / 6.6) with 0.7 A bandwidth. Image is recorded by detector DMX 41AU 02.AS Imaging Source (1280 x 960 pixels, 4.65 &#956;m, 8 bits) that is incorporated on a mounting, Vixen Sphinx. <br /> <br /> Those sun image then enhanced using freeware, Registax. Furthermore health freeware, Image J was used as a wide measurement instruments of Plage and Sunspot. Tresholding methods Huang (1994) and Otsu (1979) also used to facilitate the detection of those object.