APOD: The Sun Rotating (2014 Mar 12)

[APOD Robot]

The Sun Rotating

Explanation: Does the Sun change as it rotates? Yes, and the changes can vary from subtle to dramatic. In the above time-lapse sequences, our Sun -- as imaged by NASA's Solar Dynamics Observatory -- is shown rotating though the entire month of January. 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-colored 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. This year our Sun is near its Solar maximum activity of its 11-year magnetic cycle. As the video ends, the same large and active sunspot region previously mentioned rotates back into view, this time looking differently.

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[Boomer12k]

How fascinating.

:---[===] *

[CURRAHEE CHRIS]

That was really cool!! I have only taken an interest in astronomy for little over 2 years now and the sun is just one of those things that has never really seemed inspiring or interesting to me. It just seems so timeless yet you look at videos like that and it makes you see how active the sun is and how precarious our solar system is/can be. I've never been so amazed at how much energy is ripping through the sun until i realize the immense distance it is from us.

At times it seemed like that video- the large one on the left was 3D??? I feel like I could see regions where the sunspots were where the sunspots were more depressed than the normal shell of the sun.

Really neat video!!

[rstevenson]

I never knew the Sun could play a synthesizer!

Rob

[Beyond]

It even has it's own song. I am your sunshine, your only sunshine...

[Guest]

<-- also finds the music distracting.

[neufer]

<-- also finds the music distracting.

I liked the music. Way to go, Gill

[BMAONE23]

I never knew the Sun could play a synthesizer!

Rob

At least it wasn't a synthesized Sun

[BMAONE23]

That was really cool!! I have only taken an interest in astronomy for little over 2 years now and the sun is just one of those things that has never really seemed inspiring or interesting to me. It just seems so timeless yet you look at videos like that and it makes you see how active the sun is and how precarious our solar system is/can be. I've never been so amazed at how much energy is ripping through the sun until i realize the immense distance it is from us.

At times it seemed like that video- the large one on the left was 3D??? I feel like I could see regions where the sunspots were where the sunspots were more depressed than the normal shell of the sun.

Really neat video!!

The Coronal Hole at the top of our closest Star certainly appears to sink into the surface of the largest disk

[geckzilla]

I also enjoyed the music. It was calming and not intrusive. And, technically, the images of the sun were entirely synthesized. Or did you think you were looking at the actual sun?

[LocalColor]

Wow - watched the video over and over. Another great APOD - thanks!

[Anthony Barreiro]

That was really cool!! I have only taken an interest in astronomy for little over 2 years now and the sun is just one of those things that has never really seemed inspiring or interesting to me. It just seems so timeless yet you look at videos like that and it makes you see how active the sun is and how precarious our solar system is/can be. I've never been so amazed at how much energy is ripping through the sun until i realize the immense distance it is from us.

At times it seemed like that video- the large one on the left was 3D??? I feel like I could see regions where the sunspots were where the sunspots were more depressed than the normal shell of the sun.

Really neat video!!

The Sun is one of the best celestial objects to observe through any telescope. Unlike any other star, the Sun is close enough that we can resolve surface details with very modest telescopes. With a safe white light filter you can watch sunspots develop and rotate across the Sun's surface from one day to the next. With a hydrogen-alpha filter you can see the same sort of plumes and tendrils of gas in the Sun's atmosphere seen in the large image in this video. And the Sun is visible during the day, so you don't have to stay up late!

[neufer]

The Sun is one of the best celestial objects to observe through any telescope. Unlike any other star, the Sun is close enough that we can resolve surface details with very modest telescopes. With a safe white light filter you can watch sunspots develop and rotate across the Sun's surface from one day to the next. With a hydrogen-alpha filter you can see the same sort of plumes and tendrils of gas in the Sun's atmosphere seen in the large image in this video. And the Sun is visible during the day, so you don't have to stay up late!

---

[list]The sun was shining on the sea,
Shining with all his might:
He did his very best to make
The billows smooth and bright--
And this was odd, because it was
The middle of the night.

The moon was shining sulkily,
Because she thought the sun
Had got no business to be there
After the day was done--
"It's very rude of him," she said,
"To come and spoil the fun!"[/list][/color]

[Ron-Astro Pharmacist]

<-- also finds the music distracting.

I liked the music. Way to go, Gill

I'll ditto that. The music was quite appropriate. And on that note Wki had an interesting comment, "If in fact the sun had an atmosphere, and we could hear the sun, it would be roughly equivalent to every loud speaker from every concert in our earth's history."

From 93 million miles I would be curious to hear its sound at the, also appropriate, decibel level. Wonder what it would be telling us?

[Craig Willford]

I wonder what is the mechanism to drive the sun's equator to rotate at a speed different than the higher latitudes.

It doesn't exhibit bands of opposite direction winds, as with Jupiter and the other gas planets, so the Coriolis effect doesn't seem to apply.

You would think the angular rotation rate would be the same at any latitude.

Craig Willford

[CURRAHEE CHRIS]

The Sun is one of the best celestial objects to observe through any telescope. Unlike any other star, the Sun is close enough that we can resolve surface details with very modest telescopes. With a safe white light filter you can watch sunspots develop and rotate across the Sun's surface from one day to the next. With a hydrogen-alpha filter you can see the same sort of plumes and tendrils of gas in the Sun's atmosphere seen in the large image in this video. And the Sun is visible during the day, so you don't have to stay up late!

Thanks for that. My initial response was what about my eyes but you've adequately addressed that with the filters. Also very interesting post on the sound the sun would emit if it had an atmosphere. Good thing it doesnt!! My wife says its hard enough to get a good night sleep with my snoring!!

[Chris Peterson]

And on that note Wki had an interesting comment, "If in fact the sun had an atmosphere, and we could hear the sun, it would be roughly equivalent to every loud speaker from every concert in our earth's history."

From 93 million miles I would be curious to hear its sound at the, also appropriate, decibel level. Wonder what it would be telling us?

The Sun does have an atmosphere, and does produce sounds. You could figure out how loud it would sound from the Earth if someone has published an acoustic energy level at its surface, as you'd then just apply the inverse square law.

[Nitpicker]

I wonder what is the mechanism to drive the sun's equator to rotate at a speed different than the higher latitudes.

It doesn't exhibit bands of opposite direction winds, as with Jupiter and the other gas planets, so the Coriolis effect doesn't seem to apply.

You would think the angular rotation rate would be the same at any latitude.

Craig Willford

The differential rotation is only in the outer third of the Sun, in the convective zone. The differential rotation is "typical" fluid behaviour driven by the solid-body rotation of the interior.

There is an excellent (and concise) article on the transition zone between the Sun's radiative interior and convective exterior, here:
http://en.wikipedia.org/wiki/Tachocline

The graph of the tachocline in the article (which I saw yesterday for the first time) is my new favourite graph. It reminds me of -- and seems analogous to -- the solutions to certain differential equations, where a slight difference in initial conditions results in a significantly different outcome.

[Boomer12k]

We Love you, SUN!!!!!!
Thank you for all the light and heat!!!!

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