Sunspot data for 31 July 2025 of period 2025Q3: (PREV DAY - NEXT DAY)
| Sun250731_1744UTC_sketch.jpg | Sun250731_1749UTC.jpg |
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 |  Click here for the sharpened image. |
Today was mainly grey, but in the evening it cleared to about 40% cumuli topped with patches of cirrus and an otherwise hazy sky. Transparency in between was poor, but the scintillation monitor reported reasonable seeing on average. I made the following observation:
Observation date/time: 31 July 2025 17:44 UTC Telescope: GTT60 (Galileo Type Telescope) Focal length: 1490mm (plano convex singlet) Aperture: 60mm Stop: 30mm Eyepiece: -75mm (plano concave singlet, 24mm aperture) Observation type: projection (350mm distance, 80mm diameter) Reference: Earth's rotation axis Exposure (transparency): 1.080ms (using 82nm bandwidth green filter) Seeing (SSSMon): 3.0-4.0" (1.5" at best) =================================================================== Total number of sunspots: 20 | |
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