Contains:  Solar system body or event
4 days solar rotation, Dennys_T

4 days solar rotation

4 days solar rotation, Dennys_T

4 days solar rotation

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Description

My mini project here was to measure the width of our star in pixels, the position of sunspots at a few days interval in order to calculate the sun’s rotation period. Assuming that each spot is not in movement on the surface itself (only moving with the surface) and that the sphere is a perfect one (near true as it is only 10km flatter at the poles than the equator).

Earth’s revolution around the sun was taken into account in my calculation, raising by a few degrees the measured rotation over 3 days, and also that the monitored spots were not traveling along the equator, bringing another correction into the final figure.

Results: a rotation of 43.25 degrees over 73 hours resulting in a 26.63 days rotation for spots at 11.5 degrees above equator. The exact value is 25 days at equator and 34 at the poles. By interpolating for 11.5 degrees north, we obtain 26.15 days, so an approximate error of 1.8% on my calculations.

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Astro-Québec
Imaged with APT