Wednesday, April 19, 2006
The Sodium doublet
Steven previously mentioned his favorite absorption line in the sun's spectrum as sodium. And what's not to like: Strong, conspicuous, identical to the emission you see from low-pressure sodium lights, the sodium doublet is to the Fraunhofer lines like a hot dog is to ballpark food.
With this image I experimented with a vertical blur to remove the variations in intensity along the length of the slit due to dust, irregular coatings, and a small piece of crud in the digital camera. The spectrum is also sharpened, so you can't use this image to find astrophysical data.
The color is weird--I am always surprised how redward the sodium doublet is from where I think it should be in the yellow, but in reality it's more orange than yellow. And yellow is visually such a small portion of the spectrum that there isn't much to it.
Other spectrum posts:
The Solar Spectrum: Magnesium Green