Diving Into Sunspots

Sunspots Revealed

First view of what goes on below the surface of sunspots. Lighter/brighter colors indicate stronger magnetic field strength in this subsurface cross section of two sunspots. For the first time, NCAR scientists and colleagues have modeled this complex structure in a comprehensive 3D computer simulation, giving scientists their first glimpse below the visible surface to understand the underlying physical processes. (Click to embiggen.)

Today’s what lots of folk think of as the first day of summer for us northern hemisphere types and first day of winter for the southern hemisphere folks. (It’s actually the mid-point, marking the point when the Sun is the farthest north in its yearly path across the sky.)  Today’s the solstice and FATHER’s DAY here in the U.S…. and just in time for this auspicious occasion, the folks at National Center for Atmospheric Research (NCAR) and the Max Planck Institute for Solar System Research bring us a wonderful computer model of sunspots.  I’m dedicating today’s entry to my dad, who loves to look at sunspots! This one’s for you, Daddy!

The interface between a sunspot's umbra (dark center) and penumbra (lighter outer region) shows a complex structure with narrow, almost horizontal (lighter to white) filaments embedded in a background having a more vertical (darker to black) magnetic field. Farther out, extended patches of horizontal field dominate. For the first time, NCAR scientists and colleagues have modeled this complex structure in a comprehensive 3D computer simulation, giving scientists their first glimpse below the visible surface to understand the underlying physical processes. (©UCAR, image courtesy Matthias Rempel, NCAR.

The high-res simulations of sunspots are an important tool for scientists to learn more about these blots of seemingly dark regions on the Sun (I say “seemingly” because they’re actually just cooler than the surrounding area, thus appearing darker).  Sunspots are manifestations of the magnetic fields that play across the Sun’s surface.  They’re also closely associated with massive ejections of material that can come straight at Earth and cause things like aurorae, or even go so far as to disrupt our communications networks and power systems. You may have heard of the term “space weather” — well, sunspots are often involved in the processes that cause space weather.  If you’ve been following the Space Weather FX project I’ve been working on for Haystack Observatory, we’ve been talking a lot about the effects of space weather on all kinds of systems.

Creating detailed simulations of sunspots would not have been possible even as recently as a few years ago. But now, we have the latest generation of supercomputers and a growing array of instruments to observe the Sun — and when you marry the two, you can get some amazing simulations of real life. Partly because of such new technology, scientists have made advances in solving the equations that describe the physics of solar processes. The Sun is a complex object, ever-changing and difficult to probe. So, coming up with a computer model is an important step. “This is the first time we have a model of an entire sunspot,” says lead author Matthias Rempel, a scientist at NCAR’s High Altitude Observatory. “If you want to understand all the drivers of Earth’s atmospheric system, you have to understand how sunspots emerge and evolve. Our simulations will advance research into the inner workings of the Sun as well as connections between solar output and Earth’s atmosphere.”

Outward flows from the center of sunspots were discovered a hundred years ago, and ever since then, atmospheric physicists have been working on explanations for the very complex structures they see in sunspots. This includes the fact that their numbers rise and fall during each 11-year solar cycle.

The work was supported by the National Science Foundation, NCAR’s sponsor. The research team improved a computer model, developed at MPS, that built upon numerical codes for magnetized fluids that had been created at the University of Chicago.  GO read more about it (and see some of their really COOL videos) at the UCAR/NCAR web site.

Magnetar the Magnificent, Reprise

Magnetars!

Magnetars are the most intensely magnetized objects in the universe. Their magnetic fields are some 10,000 million times stronger than Earth’s. If a magnetar were to magically appear at half the Moon’s distance from Earth, its magnetic field would wipe the details off every credit card on Earth.

We’ve got another podcast up today at 365 Days of Astronomy, this one about magnetars. These cosmic beasts are in the news again this week, with the discovery of another one about 15,000 light-years away from us. Astronomers have known about these beasts since 1979, but didn’t really figure them out until a few years ago.

Now, they’re seeing them in various places, including this most recent one — which wasn’t even on the map until its outburst was detected in 2008.  The outburst occurred when the unstable configuration of object’s magnetic field pulled on the magnetar’s crust, allowing matter to spew outwards in sort of exotic volcanic eruption. The outbursting matter tangles with the magnetic field which itself can change its configuration, releasing more energy.

There haven’t been a lot of these strange beasts located in the galaxy, yet.  With this new one, the count comes to 15, but there will be more found as they wake up and send outbursts our way.  The tools are out there to discover them — XMM-Newton and INTEGRAL are sensitive to the soft gamma-ray emissions of magnetars

So, go on over and listen to our podcast, and if you want more info about magnetars, I’ve got a page up here.

Enjoy!

What Species Do You Belong To?

A Species that Can Do THIS

It’s cool to be part of a group of beings that can do something this amazing. Now, if we could just harness our smarts to guide the rest of our destiny so beautifully!