China's space lab has a spot in the Sun

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May 14 2012 6:30 AM

China's space lab has a spot in the Sun

On May 11, the phenomenal astrophotographer Thierry Legault took another amazing picture of the Sun (See Related Posts below for more of Thierry's work that's been featured here at the BA blog). Setting up his equipment in the south of France, he captured this truly magnificent shot of our nearest star... and when you finish picking your jaw off the floor, stick around, because your amazement isn't done yet:

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Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death from the Skies! Follow him on Twitter.

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[Click to hugely ensolarnate.]

I know, right? That HUGE sunspot cluster is Active Region 1476, which has been blorting out some small flares, but nothing major. That's a bit surprising, given how big and active the magnetic field is in those spots. Still, the cluster has grown to something like 200,000 km (120,000 miles) stem to stern, and that one big spot is 100,000 or so km (60,000 miles) across. Mind you, the Earth is about 13,000 km (8000 miles) across, so keep that in mind when you're looking at it.

But there's more to see! Including the reason Thierry took this picture in the first place...

See the circle to the left of the spot? Thierry put that in there to mark the location of something else. See the tiny dot in the middle of the circle? That may not look like much, but it's important.

Thierry chose the time and location of this picture very carefully. From his location in France, at that time, the Chinese spacecraft Tiangong-1 could be seen crossing the Sun's face! That's what that dot is. Tiangong-1 is actually the first module of China's planned space station. It's small, only about 10 meters long, and was about 540 km (320 miles) from Thierry when he took this image. The module is orbiting the Earth at roughly 8 km/sec (5 miles/sec) so it took less than a second to transit the Sun!

I love how you can see the solar panels, perfect little lines sticking out of the main body of the module. From that distance, the module is about 4 arcseconds long -- that's a unit of size on the sky, where for comparison the Sun is about 1800 arcseconds across. So Tiangong-1 is very tiny indeed compared to the Sun, even though the Sun is more than 250,000 times farther away!

So, in many ways, this is a truly remarkable photograph.

And keep your eyes on that sunspot cluster (though not literally, because ow). If it decides to make its presence known again, I'll have something up here on the blog as soon as I know. You can also check Space Weather for current news on solar activity.



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