Sunspot data for 4 September 2025 of period 2025Q3: (PREV DAY - NEXT DAY)

Sun250904_0803UTC_sketch.jpgSun250904_0805UTC.jpg





Click here for the sharpened image.
today we had large patches of densely packed cumuli. Transparency in between was good, and the scintillation monitor reported very good seeing on average. I made the following observation: 
Observation date/time:   04 September 2025 08:03 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 (349mm distance, 80mm diameter)
Reference:               Earth's rotation axis
Exposure (transparency): 0.530ms (using 82nm bandwidth green filter)
Seeing (SSSMon):         1.3-1.8" (1.0" at best)

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Total number of sunspots:  38

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