Chemical Composition of Stars

What is the purpose of fingerprints? How are fingerprints useful? Where do you see fingerprints being used?

Activity Students are to press their thumb gently onto the ink pad and then press their thumb onto the notes Students should wipe the ink off their thumb with the wipe provided Students should compare/contrast their fingerprint with their neighbor.

Types of Fingerprints

Review-Electromagnetic Spectrum

Spectrometer Students will put on the glasses provided and take note of the spectral lines that appear on the right (3:00 position) Students should write notes as to what colors are being observed and in which order the colors appear Students will reproduce what they observed using colored pencils on the spectrometer worksheet provided for two gases

Class Discussion How did the fingerprint activity relate to the spectrograph activity? Each person has a unique set of fingerprints and each element of a star has a unique line spectrum By comparing a star’s spectrum with the spectrum of known elements, astronomers can infer how much of each element is found in the star

Examples of Line Spectrums of Elements

Chemical Composition Of Stars In Clusters Can Tell History Of Our Galaxy and Others Doppler effect If the spectral lines are shifted toward the blue end of the spectrum for the star, then the star is moving towards us. If the dark lines are shifted toward the red end of the spectrum for the star, it is moving away from us.

Animation http://www.classzone.com/books/earth_science/terc/content/visualizations/es2802/es2802page01.cfm