The Sun and its Danger Zone: The Chromosphere

One of the deeply confusing aspects of our Sun (and other stars) is their temperature structure. Starting in the core, the Sun is millions of degrees kelvin and supports nuclear burning. As you leave the nuclear burning core and climb first into the radiative zone and then the convective zone, the temperature systematically drops until it reaches a temperature of several 1000 degrees at a star’s surface. This makes sense. In the core, the gas is being compressed under the pressure of all the upper layers of the star gravitationally pushing down. The pressure allows nuclear reactions to release energy in a form that can heat things up: specifically light. That light then interacts with stellar material, being absorbed and reabsorbed over and over as it loses energy and goes on a random walk through the radiative region (think light bulb heating the air around it), and then (think of the lava lamp material above a light bulb) it also gives off energy as it heats cells of material at the base of the convective zone that rise and convectively give off heat as the cells rise (and then, when cool, sink back down).

So far so good.

The problem is, as you then move away from the surface of the Sun, you enter regions where the temperatures again go up – A lot – like back to millions of degrees hot levels of a lot!

And no one fully knows why. This is a very counter intuitive situation. Imagine that the surface of a lava lamp was 23C and the air half an inch away was 200C! In a press conference Wednesday, astronomers announced that they think they may have found a starting point for understanding what is going on in this bizarre situation.

Read More

Party at the AAS

Party at the AAS

210_invitation.gifTonight there will be a celebration of community building involving cocktails. To get details, just get Out of the Rain. (or look at the card at left)
 
 
 
 
 
 
 
 
 
 
 

Read More

Giving AAS a Face

Giving AAS a Face

img_9215.jpgThere is an excellant collection of photos from the conference (including one of yours truly) over at the 808scenezine.com that were taken by Katie Whitman. I’m still running around a bit madly, but I’ll be adding pictures to things. For now, get your photo fix here.

Read More

“The Universe” on TV

“The Universe” on TV

theuniverse.JPGA new player has emerged on the science special scene. The History Channel is premiering “The Universe” tonight. You can watch “The Universe” Tuesdays at 8pm/9c. The first episode is on “The Sun.” Here is what they plan to talk about:

Read More

All the news you’ll see again: Solar Atmospheric Heating, Tidal Tails, and Crab Nebula Explosion Date

Here’s highlights of the news I’ll be talking about later:

  • Scientists have (again) found new tidal streams of material around the galaxy from a previously unknown, now shredded galaxy
  • Scientists have (again) found a new explanation of how the Sun heats its chromosphere
  • Scientists have (again) dated the Crab Nebula explosion to 1054 AD
  • New results, new press conferences and press releases, and, well, the same old same old. Science moves forward in incremental steps, and sometimes things circle and circle as they slowly move forward.

    Read More
Now live! Expect the Unexpected.
Currently offline.