scroll to top
Stuck on your essay?
Get ideas from this essay and see how your work stacks up
Word Count: 393
Have you ever looked up at the sky and wondered whatare those bright and shiny things up thereStars a natural luminious body visible in the skyespecially at night A self-luminious gaseous celestial bodyofgreat mass which produces energy by means of nuclearfusion reactions whose shape is usually spheroidal andwhose size may be as small as the earth or larger than theGalaxies Any of the very large groups of stars andassociated matter that are found throughout the universe In 1802 William Wollaston noted that the spectrum ofsunlight did not appear to be a continious band of colorsbut rather had a series of dark lines superimposed on itWollaston attributed the lines to natural boundaries betweencolors Joseph Fraunhofer made a more careful set ofobservations of the solar spectrum in 1814 and found some600 dark lines and he specifically measured the wavelenghtof 324 of them Many of the Fraunhofer lines in the solarspectrum retain the notations he created to designate themIn 1864 Sir William Huggins matched some of these darklines in the spectra from other stars with terrestrialsubstances demonstrating that the stars are made of thesame materials of everyday material rather than exoticsubstances This paved the way for modern spectroscopySince even before the discovery of the spectrascientists had tried to find ways to catergorize stars Byobserving spectra astronomers realized that the largenumbers of stars exhibit a small number of distinct patternsin their spectral lines Classification by the spectralfeatures quickly proved to be a powerful tool forThe current spectral classification scheme wasdeveloped at Harvard Observatory in the early 20thcentury Work was begun by Henry Draper whophotographed the first spectrum of Vega in 1872After his death his wife donated the equipment anda sum of money to the Observatory to continue hiswork The bulk of classification work was done byAnnie Jump Cannon from 1918 to 1924 The originalscheme used capital letters running alphabetically but the subsequent revisions have reduced this asstellar evolution and typing has become betterunderstood
@Kibin is a lifesaver for my essay right now!!
- Sandra Slivka, student @ UC Berkeley
Wow, this is the best essay help I've ever received!
- Camvu Pham, student @ U of M
If I'd known about @Kibin in college, I would have gotten much more sleep
- Jen Soust, alumni @ UCLA