Presentation Information
[O12-P103]Comparison of sunspot area ratios obtained from solar imaging using smart telescopes with various phenomena in space weather forecasting.
*Kaito Momose1, *Harutugu Uekusa1, *Taichi Ozasa1, *Naotaro Shigemoto1 (1. Hongo senior high school)
Keywords:
Sunspot relative number,Sunspot area ratio,High-energy particles,Solar wind
1. Background and Objectives of the Research
Solar activity has become more active since July 2025, and solar flare activity has entered a period of maximum activity. The number of sunspots changes in a cycle of approximately 11 years, with the period of maximum activity being called the solar maximum and the period of minimum activity being called the solar minimum. During the solar maximum, solar flares occur frequently, and there is a risk that phenomena such as the Dellinger effect may disrupt daily life. We decided to investigate the correlation between the number of sunspots and various solar phenomena and consider the possibility of their impact on daily life. In addition, based on similar previous research on the sun, we decided to conduct sunspot observations using our own measurement method.
2. Observation Method
Starting in January 2026, we began photographing the sun every Saturday after school using a smart telescope (ZWO-SeestarS30) (Photos 1 and 2). To determine the ratio of sunspot area to photosphere area, we used image processing software (ImageJ), but due to large errors during binarization, we decided to calculate it manually. We imported the image in grayscale, aligned the edge of the photosphere with a circle of 25 cm in diameter, and printed it out on B4 paper (Figure 1). We measured the area of sunspots on the 25 cm diameter photosphere surface of the sun using 1 mm grid technical paper (Photo 3). For the area, we used a 1 mm x 1 mm grid as one square, counting a square that was almost completely black as 1 and an incomplete square as 1/2. To account for individual differences, we performed the same task three times (by three people) and calculated the average. The calculated sunspot area ratio was compared with the relative number of sunspots obtained from space weather forecasts (Figure 2), solar X-rays, proton phenomena (Figure 3), high-energy electron influences (Figure 4), geomagnetic data, radiation belt electrons, geomagnetic storms, and Dellinger phenomena.
3. Results
The area ratio obtained from the aggregation is shown in Figure 5. The apparent area of the sun is defined as the area of a circle when the spherical sun is viewed from the observation point, and the ratio to the sunspot area is shown by a broken line. From Figure 5, the ratio of the sunspot area to the apparent area of the sun (hereinafter referred to as the sunspot area ratio) fluctuated between approximately 0.003 and 0.07. Furthermore, when comparing February 6th, which had the highest sunspot area ratio in Figure 5, with Figure 4, the fluence of high-energy electrons in Figure 4 was extremely low, at one-tenth of the normal level. In addition, when comparing Figure 3 and Figure 4, high-energy protons increased by about 0.2 RFU (a unit indicating the intensity of high-energy protons from the sun) on February 24th and 25th, when the relative number of sunspots was low. Furthermore, Figure 6, which shows the correlation between the sunspot area ratio and the relative number of sunspots, showed a positive correlation with a correlation coefficient r = 0.0003.
Solar activity has become more active since July 2025, and solar flare activity has entered a period of maximum activity. The number of sunspots changes in a cycle of approximately 11 years, with the period of maximum activity being called the solar maximum and the period of minimum activity being called the solar minimum. During the solar maximum, solar flares occur frequently, and there is a risk that phenomena such as the Dellinger effect may disrupt daily life. We decided to investigate the correlation between the number of sunspots and various solar phenomena and consider the possibility of their impact on daily life. In addition, based on similar previous research on the sun, we decided to conduct sunspot observations using our own measurement method.
2. Observation Method
Starting in January 2026, we began photographing the sun every Saturday after school using a smart telescope (ZWO-SeestarS30) (Photos 1 and 2). To determine the ratio of sunspot area to photosphere area, we used image processing software (ImageJ), but due to large errors during binarization, we decided to calculate it manually. We imported the image in grayscale, aligned the edge of the photosphere with a circle of 25 cm in diameter, and printed it out on B4 paper (Figure 1). We measured the area of sunspots on the 25 cm diameter photosphere surface of the sun using 1 mm grid technical paper (Photo 3). For the area, we used a 1 mm x 1 mm grid as one square, counting a square that was almost completely black as 1 and an incomplete square as 1/2. To account for individual differences, we performed the same task three times (by three people) and calculated the average. The calculated sunspot area ratio was compared with the relative number of sunspots obtained from space weather forecasts (Figure 2), solar X-rays, proton phenomena (Figure 3), high-energy electron influences (Figure 4), geomagnetic data, radiation belt electrons, geomagnetic storms, and Dellinger phenomena.
3. Results
The area ratio obtained from the aggregation is shown in Figure 5. The apparent area of the sun is defined as the area of a circle when the spherical sun is viewed from the observation point, and the ratio to the sunspot area is shown by a broken line. From Figure 5, the ratio of the sunspot area to the apparent area of the sun (hereinafter referred to as the sunspot area ratio) fluctuated between approximately 0.003 and 0.07. Furthermore, when comparing February 6th, which had the highest sunspot area ratio in Figure 5, with Figure 4, the fluence of high-energy electrons in Figure 4 was extremely low, at one-tenth of the normal level. In addition, when comparing Figure 3 and Figure 4, high-energy protons increased by about 0.2 RFU (a unit indicating the intensity of high-energy protons from the sun) on February 24th and 25th, when the relative number of sunspots was low. Furthermore, Figure 6, which shows the correlation between the sunspot area ratio and the relative number of sunspots, showed a positive correlation with a correlation coefficient r = 0.0003.