Presentation Information
[O12-P41]Will Jupiter's South Equatorial Belt disappear?
*Chinami Sasaki1, Yukina Ikeda1, Mei Hanaki1, Manami Nishi1, Mizuki Kamimura1, Noa Kamimura1, Yui Amameishi1, Riko Akimaru1, Koharu Uto1 (1. Kokubu High School)
Keywords:
Jupiter,South Equatorial Belt,disappearing
Since the year before last, we have been continuing our research on phenomena occurring on Jupiter's surface while photographing it. The most prominent features on Jupiter's surface are the Great Red Spot and the two equatorial belts. We learned that the South Equatorial Belt disappears with a period of 3 to 15 years, and began our investigation. We connected a CMOS camera to a 200mm aperture, 2032mm focal length Schmidt-Cassegrain reflecting telescope. We used a Takahashi EM200 TemmaPC-Jr equatorial mount to track the planet. We used a 2x Barlow lens and UV/infrared cut filters on the CMOS camera for imaging. The camera was connected to the telescope tube via the 2x Barlow lens, and the CMOS camera was connected to a laptop computer. We captured images as video, and the data was saved to the HDD. We launched the SharpCap software on the computer to capture images. We selected the camera's exposure time per frame with Exposure and the image resolution with Gain, while focusing on the planet. For the video footage, we adjusted the shooting time to 35 seconds and the number of still images to 2000, taking into account post-processing of the images. After shooting, the video data was stacked using AutoStakkert!. After stacking, we used RegiStax6 to create sharp planetary images. We used the planetary analysis software WINJUPOS to measure the major axis of Jupiter's Great Red Spot and the width of its two equatorial stripes. For past Jupiter image data, we used data published on the Lunar and Planetary Research Society's website. From 2024 to 2025, we measured the width of the two equatorial stripes ourselves, using 32 images over 8 days at 160 locations, and measured the width of the two equatorial stripes using 25 images over 25 days at 125 locations from the Lunar and Planetary Research Society's website data. In addition, from 2009 to 2010, when the South Equatorial Belt was previously absent, we measured the width of the two equatorial stripes using 22 images over 22 days at 110 locations from the Lunar and Planetary Research Society's website data. According to AstroArts (2010), the South Equatorial Belt disappears in cycles of 3 to 15 years, with the most recent disappearance occurring in early May 2010. Based on data from the Lunar and Planetary Research Society, we measured the width of the South Equatorial Belt. Before its disappearance, the width of the South Equatorial Belt was approximately 11,500 km, but it shrunk to approximately 9,500 km just before its disappearance. From the most recent Figure 2, it can be seen that it fluctuates between approximately 10,500 km and approximately 9,500 km. Based on the above, considering the change in its width, it is thought that the disappearance of the South Equatorial Belt will occur soon. We also compared the color changes of the two equatorial belts between 2009-2010 and 2024-2025. Jupiter image data was loaded into StellaImage, decomposed into RGB, graphed in Macali, and compared. The disappearance of the South Equatorial Belt in 2010 did not involve a general fading of color; rather, the central part of the belt faded first, followed by a rapid disappearance of both ends just before its complete demise. As of late March 2026, no fading from the central part of the South Equatorial Belt has been observed. Approximately 16 years have passed since the disappearance of the South Equatorial Belt in May 2010, and it has been observed that the width of the South Equatorial Belt is fluctuating but showing a tendency to shrink. Furthermore, fading in the central part of the belt has not yet occurred, and we would like to continue observing future changes. In the event that the South Equatorial Belt disappears, we would also like to pay attention to changes in other features on Jupiter's surface before and after the disappearance.