Sunspot data for 21 April 2021 of period 2021Q2: (PREV DAY - NEXT DAY)

Sun210421_0920UTC_sketch.jpgSun210421_0933UTC.jpg


today we had a fully overcast dull morning, but around 9am UTC a small clearance went over the observatory, just enough to do the following observation:
Observation date/time: 21 April 2021 @ 09:20 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 (340mm distance, 80mm diameter)
Reference:             Earth's rotation axis

===================================================================
Number of groups:      3
Group 1:
    Number of sunspots:    2
Group 2:
    Number of sunspots:    4
Group 3:
    Number of sunspots:    1
-------------------------------------------------------------------
Total number of sunspots: 7

PREV DAY - NEXT DAY

Home Geodesy Navigation Astronomy Literature
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