The Growth and Decay of Individual Sunspots and Pores

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 data for the period 2010 May–2025 March, ≈3.5 × 10 ^5 sunspots and pores were detected and their evolution tracked. The growth and...

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Bibliographic Details
Main Author: Andrei G. Tlatov
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:The Astrophysical Journal
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Online Access:https://doi.org/10.3847/1538-4357/ade790
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Summary: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 data for the period 2010 May–2025 March, ≈3.5 × 10 ^5 sunspots and pores were detected and their evolution tracked. The growth and decay rates of sunspots depend nonmonotonically on the area. For small-area sunspots S  ≲ 50 μ sh, a rapid increase in velocity is observed with increasing area for the growth stage $d{S}_{{\rm{sp}}}^{{\rm{gr}}}\approx 0.2\cdot {S}^{1.35}$ and for the decay stage $d{S}_{{\rm{sp}}}^{{\rm{dc}}}\approx 0.28\cdot {S}^{1.26}$ μ sh day ^−1 . For sunspots S  ≳ 50 μ sh, the growth rate depends weakly on the area: $d{S}_{{\rm{sp}}}^{{\rm{gr}}}\approx 11.9\cdot {S}^{0.32}$ μ sh day ^−1 . For the decay stage of sunspots with an area of S  ≈ 50–150 μ sh, the decay rate also depends weakly on the area and can be approximated as $d{S}_{{\rm{sp}}}^{{\rm{dc}}}\approx 11\cdot {S}^{0.15}$ . For sunspot areas S  ≳ 150 μ sh, the decay rate accelerates with increasing area: $d{S}_{{\rm{sp}}}^{{\rm{dc}}}\approx 0.14\cdot {S}^{0.96}$ μ sh day ^−1 . 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 μ sh, the growth and decay rates of sunspots of trailing polarity are higher than those of sunspots of leading polarity.
ISSN:1538-4357