Identify this Celestial Body


Phil Plait @ Discovery Magazine explains:

The Sun’s surface puts out light at all wavelengths, but the surface isn’t solid. It’s a gas, and it tapers off with height. Normally, a thin gas in space emits light at very specific colors as electrons jump from one energy level to another in the individual atoms. But compressed gas in the thicker, denser part of the Sun mashes together all those energies, spreading them out, so it emits white light (that layer of the Sun is called the photosphere). Above that layer, where the gas is thinner (in a layer called the chromosphere), the hydrogen does emit light at specific colors. One of these, Hα, is in the red part of the spectrum, and in fact hot, thin hydrogen emits very strongly in Hα.

By plopping a filter in front of a telescope, you can block a lot of the light from the photosphere but let light from the chromosphere through. That’s what Alan Friedman did — he used a filter that let through a very narrow range of colors centered on Hα — to get this stunning picture. Well that, plus quite a bit of image processing! But everything you’re seeing there is real, and is happening on the Sun.


[via Kottke]


November 5, 2010. Tags: , , , , , , , , , , , , . Smarts. Leave a comment.

Sun Spot

Ink drawing of a sun spot circa 1888.

[via Robin Sloan @ Snarkmarket]

October 13, 2010. Tags: , , , , , , , , . Art. Leave a comment.

Asteroid Discoveries 1980-Present

Where I work, there is an ongoing debate about the relative merits of actual measurements and statistical modeling.  Measurements tell you what’s _actually_ going on in reality, but in terms of time and money, it’s expensive.  Statistical modeling is faster and cheaper, but less accurately describes what’s _actually_ going on in reality.

I think this video demonstrates one instance of a seamless blend of measurements and modeling.

[…] asteroids that were discovered from 1980 to 2010 appear in the sequence as they were discovered.

Note that a new pattern emerges in 2010,

with discovery zones in a line perpendicular to the Sun-Earth vector. These new observations are the result of the WISE (Widefield Infrared Survey Explorer) which is a space mission that’s tasked with imaging the entire sky in infrared wavelengths.

[via John Farrier @ Neatorama]

August 28, 2010. Tags: , , , , , , , . Video. Leave a comment.

How close can you get to the sun without dying?

Surprisingly close.

The sun is about 93 million miles away from Earth, and if we think of that distance as a football field, a person starting at one end zone could get about 95 yards before burning up.

That equates to about 3 million miles before you go poof.

[Alessandra Calderin @ Popular Science via John Farrier @ Neatorama]

[photo via NYT]

July 22, 2010. Tags: , , , , , , , , , . Smarts. Leave a comment.