Saturday, 6 July 2013

Photography: Sun Spots

As the Meterological Office records record temperatures for July, Tony Hicks presents two extraordinary photographs of the sun.

On July 5th, I photographed the sun from my back garden using a Sky Watcher 150PL with a 20mm Plossl lens and a hand-made solar filter (which I created myself) attached to the front of the telescope, using a digital camera with focal imaging.

Big southern sunspots: One of the biggest sunspot groups of Solar Cycle 24 is emerging near the sun's southeastern limb. AR1785 has a "beta-gamma-delta" magnetic field that harbors energy for powerful X-class solar flares. Another active region trailing behind it, AR1787, is only slightly less potent, with a magnetic field capable of M-class eruptions.

These sunspots are a sign that the sun's southern hemisphere is waking up. For most of the current solar cycle, the northern half of the sun has dominated sunspot counts and flare production. The south has been lagging behind--until now. June brought a surge in southern sunspots, and the trend is continuing in July.

Earth at aphelion: yesterday, you were further from the sun than usual. Earth's orbit around the sun is not a perfect circle, it's an ellipse, and on July 5th Earth is at the most distant end of the curve. Astronomers call this "aphelion." When we are at aphelion, the sun appears smaller in the sky (by 1.7%) and global solar heating is actually a little less (by 3.5%) than the yearly average

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