Astronomy for Science Fiction Writers
You know, I never remember where I find this stuff because by the time I get around to blogging it it's been sitting on my browser for three or four days.
But, anyway, here's a blog that talks about astronomy for science fiction writers:
What's a G-type star, anyhow? So of course you want your stellar navigators and scientists to talk knowledgeably about types of stars. Since I previously blogged on the properties of stars, it might be a good time to talk about what those funny letter-number codes mean. What's a G-type star, and how does it differ from an A-type? What does B4 V mean, and is it very much different from B4 III?Back in the Old Days (tm), people would study the light from stars, noting how stars would have patterns of light and dark in their spectra. The main differences causing those patters are the surface temperature and the composition of a star. The job of separating out the spectra of stars into classes fell largely to a group of women at Harvard University; they began by putting them in classes A, B, C, et cetera according to the presence or absence of spectral lines that were characteristic of various elements. A lady named Annie Jump Cannon, however, realized that by and large, the composition of stars were very similar, and so the categories that truly mattered were the temperatures. She went back through their categories, and sorted them out from highest to lowest temperature.