Tag Archives: Sol

Like the Earth, the sun rotates, as it does, it changes in both subtle and dramatic ways. To wit:

In the featured time-lapse sequences, our Sun — as imaged by NASA‘s Solar Dynamics Observatory — is shown rotating though an entire month in 2014. In the large image on the left, the solar chromosphere is depicted in ultraviolet light, while the smaller and lighter image to its upper right simultaneously shows the more familiar solar photosphere in visible light. The rest of the inset six Sun images highlight X-ray emission by relatively rare iron atoms located at different heights of the corona, all false-coloured to accentuate differences. The Sun takes just under a month to rotate completely — rotating fastest at the equator. A large and active sunspot region rotates into view soon after the video starts. Subtle effects include changes in surface texture and the shapes of active regions. Dramatic effects include numerous flashes in active regions, and fluttering and erupting prominences visible all around the Sun’s edge. Presently, our Sun is passing an unusually low Solar minimum in activity of its 11-year magnetic cycle. As the video ends, the same large and active sunspot region previously Video Credit: SDO, NASA; Digital Composition: Kevin M. Gill mentioned rotates back into view, this time looking different.

(Video: SDO, NASA; Digital Composition: Kevin M. Gill)

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Extraordinary footage from the European Space Agency’s Solar Orbiter (which still hasn’t reached its closest distance to the sun) showing surface features of our star including phenomena called “campfires” – omnipresent miniature eruptions that could be contributing to the high temperatures of the solar corona and the origin of the solar wind – too small to have been captured by previous instruments.

And that’s not all. To wit:

“Right now, we are in the part of the 11-year solar cycle when the Sun is very quiet,” says Sami Solanki, the director of the Max Planck Institute for Solar System Research in Gottingen, Germany, and PHI Principal Investigator. “But because Solar Orbiter is at a different angle to the Sun than Earth, we could actually see one active region that wasn’t observable from Earth. That is a first. We have never been able to measure the magnetic field at the back of the Sun.”

It gets better. As the mission progresses, the Solar Orbiter’s image resolution capabilities will roughly double.

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For ten years now, NASA’s Solar Dynamics Observatory has been capturing an image of Sol every 0.75 seconds from geosynchronous orbit around the earth. In this mesmeric hour long video, every second represents a day in the sun’s life, with various noteworthy events highlighted. To wit:

12:24, June 5, 2012 — The transit of Venus across the face of the Sun. Won’t happen again until 2117.

13:50, Aug. 31, 2012 — The most iconic eruption of this solar cycle bursts from the lower left of the Sun.

43:20, July 5, 2017 — A large sunspot group spends two weeks crossing the face of the Sun.

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Aggh! It’s a TIE fighter. No wait, it’s a sunspot. No wait, it’s the International Space Station. But what’s it doing on the Sun? To wit:

Transiting the Sun is not very unusual for the ISS, which orbits the Earth about every 90 minutes, but getting one’s timing and equipment just right for a great image is rare. Strangely, besides that fake spot, in this recent two-image composite, the Sun lacked any real sunspots. The featured picture combines two images — one capturing the space station transiting the Sun — and another taken consecutively capturing details of the Sun’s surface. Sunspots have been rare on the Sun since the dawn of the current Solar Minimum, a period of low solar activity. For reasons not yet fully understood, the number of sunspots occurring during both the previous and current solar minima have been unusually low.

(Image: Rainee Colacurcio)

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