Sunspot data for 21 September 2025 of period 2025Q3: (PREV DAY - NEXT DAY)
| Sun250921_1257UTC_sketch.jpg | Sun250921_1300UTC.jpg |
|---|---|
 |  Click here for the sharpened image. |
today started out grey, but in the afternoon it cleared hazy skies with cirrus and some cumuli. Transparency varied a lot, but was good at best moments. The scintillation monitor reported poor seeing on average due to the presence of thin cloud layer (visually it was much better than measured). I made the following observation:
Observation date/time: 21 September 2025 12:57 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 (347mm distance, 80mm diameter) Reference: Earth's rotation axis Exposure (transparency): 0.480ms (using 82nm bandwidth green filter) Seeing (SSSMon): 4.5-5.0" (2.0" at best) =================================================================== Total number of sunspots: 35 | |
InFINNity Deck... Astrophotography... Astro-Software... Astro Reach-out... Equipment... White papers...
Deep Sky... Solar system (Main)... Solar System (Asteroids)... Solar System (Meteors)... Solar System (Comets)... Man-made objects...
Sun Mercury Venus Moon Mars Jupiter Saturn Uranus Aurora Borealis