May 10, 2011 - Happy Birthday, Cecilia Payne-Gaposchkin

Don't you love it when someone reveals a whole new understanding of the universe?

And when that “someone” is a woman, you'd think she was unusual enough that we would have all heard of her! But I don't ever recall seeing this English-American astronomer's name before, ever!

Born on this day in 1900, Cecilia Payne studied botany, physics, and chemistry at Cambridge, in England. She completed her studies but didn't get a degree. You've probably already figured out it was because she was a woman—yep, Cambridge did not award degrees to women, back then!

While at Cambridge, Payne became fascinated by astronomy, and she went to the U.S. to study astronomy at Radcliffe (now part of Harvard). She was the first person to earn a PhD in astronomy at the college—and her paper (doctoral dissertation) was considered brilliant by at least some readers.

What Payne did was relate the type (spectral class) of stars to their actual temperatures, and she showed that the variation of the placement of the lines in a star's spectrum was caused by different temperatures, not just different amounts of the various elements.

At the time, people were sure that the Sun and other stars was made up of the same stuff as the Earth. That was what is called “the accepted wisdom” of the time. However, Payne's analysis indicated that the Sun had a lot more helium and a MILLION times more hydrogen than the Earth!

Unfortunately, Payne was just a student, and a more well-established astronomer named Henry Norris Russell persuaded her not to put forth that conclusion. Later, other evidence emerged showing that Payne, not “accepted wisdom,” was right.

And here's where science shines: Russell looked at the evidence, accepted the evidence, and changed his mind.

Here's where science doesn't always shine: once Russell, the older, more famous, astronomer, changed his mind and accepted Payne's conclusion, many other scientists gave HIM, not her, the credit!

Aack!

Anyway, I have heard of Russell, because of the famous Hertzsprung-Russell diagram showing the different types of stars. I have never—until now—heard of Cecilia Payne.

(By the way, Payne later married and became Cecilia Payne-Gaposchkin).

For more...

Read about the life and death of an average star. 

Learn about different types of stars using Astrobiology's Teacher or Student Guide. 

Here and here are worksheet activities you can use to compare various types of stars.