Chasing rainbows and revealing their secrets

With the sound of Nick's dog still ringing in my ears (see comments, previous post ) I'm now ready to reveal my fully calibrated spectrum of Sirius.

 Just to produce a "rainbow" of light from a star makes me very happy, but there's more; the dark lines are  Fraunhofer lines, and an examination of their frequencies reveals the chemical composition of the star.

Here's the 2D spectrum: 

These are 4 of the Balmer lines, at wavelengths of 410 nm, 434 nm, 486 nm, and 656 nm.  

See previous post for the science but what this really means is that light created in the centre of the star Sirius found its way to the surface and passed through the gaseous regions of its upper atmosphere. Most of the light passed through and made its way out into space, but some very specific frequencies were absorbed by the atoms in the gas. Some of the  light then travelled across space for eight and a half years,  made its way to our garden in Hatfield and revealed the fact that the gas is Hydrogen. And that's a kind of magic.

Addendum: To see much improved version with clear sharp hydrogen lines, see later post (final image) here:

http://www.fouragesofsand.com/2011/02/chasing-rainbows-making-pretty-pictures-and-the-joy-of-rspec.html