2025/06/26 by A. Tlatov, Tlatov, Andrey
Physics and Astronomy · Social Sciences · #Astrophysical Phenomena and Observations #Educational Leadership and Practices #FOS: Physical sciences #Solar and Space Plasma Dynamics #Solar and Stellar Astrophysics (astro-ph.SR)
paper · pdf · doi:10.48550/arxiv.2506.21698
openalex publication_date 2025/06/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
An analysis of the photometric growth and decay rates of sunspots and pores was carried out. According to the Solar Dynamics Observatory/Helioseismic and Magnetic Imager (SDO/HMI) data for the period 05.2010-03-2025, ≈ 3.5⋅ 10\rm 5 sunspots and pores were detected and their evolution tracked. The growth and decay rates of sunspots depend non-monotonically on the area. For small-area sunspots S \lesssim 50 μsh, a rapid increase in velocity is observed with increasing the area for the growth stage dS\rm gr\rm sp≈ 0.2 ⋅ S\rm 1.35 and for the decay stage dS\rm dc\rm sp≈ 0.28 ⋅ S\rm 1.26 μsh/day. For sunspots S\gtrsim 50 μsh, the growth rate depends weakly on the area: dS\rm gr\rm sp≈ 11.9 ⋅ S\rm 0.32 μsh/day. For the decay stage of sunspots with an area of S≈ 50 - 150 μsh, the decay rate also depends weakly on the area and can be approximated as dS\rm dc\rm sp≈ 11 ⋅ S\rm 0.15 . For sunspot areas S\gtrsim 150 μsh, the decay rate accelerates with increasing area: dS\rm dc\rm sp≈ 0.14 ⋅ S\rm 0.96 μsh/day. For solar pores, the growth and decay rates of solar pores are linearly related to the area. The growth and decay rates for the spots of the leading and trailing polarities are determined. In the range of spot areas S≈ 100 - 200 μsh, the growth and decay rates of sunspots of trailing polarity are higher than those of sunspots of leading polarity.