bootsykowan's Blog

One of the most dramatic triumphs of astrophysical spectroscopy during the 19th century was the discovery of helium. An emission line at 587.6 nm was first observed in the Solar corona during the eclipse of 1868 August 18th, although the precise wavelength was difficult to establish at the time (due to the short observation using temporary set-ups of instruments transported to Asia). Two months later, Norman Lockyer used a clever technique and managed to observe the Solar prominence without waiting for an eclipse. He noted the precise wavelength (587.6 nm) of this line, and saw that no known terrestrial elements had a line at this wavelength. He concluded that this must be a newly discovered element, and called it 'helium'. Helium was discovered on Earth eventually (1895) and showed the same 587.6 nm line. Today, we know that helium is the second most abundant element in the Universe.

We also know today that the most abundant element is hydrogen. However, this fact was not obvious at first. Many years of both observational and theoretical works culminated in 1925, when Cecilia Payne published her PhD thesis entitled 'Stellar Atmospheres'. (Footnote: this was the first ever PhD awarded at Harvard; it was also praised as "undoubtedly the most brilliant PhD thesis ever written in astronomy" nearly 40 years later. She later turned to studies of variable stars, and coined the term 'cataclysmic variables'.) In this work, she utilized many excellent spectra taken by Harvard observers, measured the intensities of 134 different lines from 18 different elements. She applied the up-to-date theory of spectral line formation, and found that the chemical compositions of stars were probably all similar, the temperature being the important factor in creating their diverse appearances. She was then able to estimate the abundances of 17 of the elements relative to the 18th, silicon. Hydrogen appeared to be more than a million times more abundant than silicon, a conclusion so unexpected that it took many years to become widely accepted.

http://imagine.gsfc.nasa.gov/docs/science/how_l1/spectr
al_what.html

======================================
The Periodic Table, Mental Health and Stars were forever connected in my brain when I heard the excitement of a young astronomer at the Smithsonian Air and Space Museum describe his discovery of a new star.  It was after 1981 because by then I was familiar with Lithium.  He said that lithium gives the early age of a star.  As the star ages, it loses lithium.  My husband's mental health disability pension depended on lithium.  It's only recently that I've accepted that Hydrogen is "the first substance" that Descartes and Spinoza were concerned with.  Today I'm seeing the 2006 documentary THE DEATH OF THE SUN.It seems it's ordinary now that first there was hydrogen and then there was helium.  Generations of chemicals.  However, it's hard to find a table of the birth through death of a star via the Periodic Table of Elements. Are all stars stamped out of the same cloth?  The same cloth our sun is?  
When I was in the 6th grade at Van Ness Elementary School, Mrs. Samenow made this statement that has always influenced how I analyze anything -- carefully.  She called it science.  She said "All we really KNOW is that there's a molecule and inside the molecule is an atom.  In your day and mine, we will never know what's inside the atom."  Six years later, I whispered to her through the air "Mrs. Samenow, now we both know what inside the atom."  They just announced the dropping of the atomic bomb on Japan.  You'll never understand the thrill that went through me.  The Periodic Table of Elements worked.  I didn't even take chemistry until I went to college, but I did make the connection.  
I get the same feeling of awe of the supernatural when reading the extract above.  It would be wonderful, if it's even true, that there is such a thing as the Periodic Table of Elements of the birth, life and death a star.  Maybe now, there are different kinds of stars with different Periodic Table elements to describe it.  Things change every day now about "heaven".
A female human, Cecilia Payne?