Sunny day, let’s image.
Sun Spotting
With the sun sunning again and after two days of learning all the stuff I should have done pre-retirement, let’s get the S50 out again.
I had tried to track the sun last week, but I summed all the images rather than stacking them, so today I’ll keep it simple. Image the sun early and late in the day, so I can see if there is any relative motion of the sun spots.
The early session had a fair bit of cloud so I took a video of it since it looks atmospheric ,:-).
I downloaded it and asked gemini to provide some melodic music to go with it, its sense of melodic seems a bit mechanistic, maybe unsurprisingly.
The sun spot images
| 9:18 am | 5:44 pm | |
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It great being surprised! My naivety in believing they would be virtually the same. Of course it’s rotated, because the earth is rotating and I’ve turned over ninety degrees. There are plenty of images of today’s sun and one of them is shown below, these images seemingly are always rotated so that the North Pole of the sun is at the top. 
The bottoms spots are horizontal so that gives me a line on my images that I can check if the big bottom spot has moved relative to the suns edge. Using Inkscape I get this
| 9:18 am | 5:44 pm | |
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So lets see the angle variation the spot has experienced,
radius = 279/2
spot_A_distance = radius - 56.6
spot_B_distance = radius - 68.7
spot_A_angle = np.arcsin(spot_A_distance/radius)
spot_B_angle = np.arcsin(spot_B_distance/radius)
np.degrees(spot_A_angle-spot_B_angle)
5.9Found out the actual answer I should have got was 4.6 degrees, so not too bad for a visual estimate.