Download Stella Finger Prints

Stellar Fingerprints
Adapted from Region 4, Fingerprints of the Stars
Objectives:
 Describe the components of the universe (stars).
 Analyze and predict trends from data.
Background:
Now that you know how astronomers use light to collect
information from the universe, let’s look at stars by
themselves. All stars start out in a specific place, called a
nebula (plural is nebulae). Nebulae are large areas of gas
and dust where stars are born and sometimes die. They are
mainly made up of hydrogen, helium, and other gases and
dust. These elements are the key ingredients in making stars.
All stars are first born of mostly hydrogen, the simplest form
of matter in space. Throughout their life, stars convert more
and more hydrogen to helium, the next simplest form of
matter.
As the stars age, they burn off their simpler (lighter) elements in a process known as
nuclear fusion. Nuclear fusion involves fusing different elements to make simpler
(lighter) elements into heavier elements such oxygen and carbon. As elements get fused
together, energy is released. As the fusion continues; the star has lower amounts of the
lighter elements. When the star eventually runs out of its "light element fuel," it tries to
fuse the heavier elements. Heavier elements require more energy to fuse.
The size of the star determines how long it lives and continues the nuclear fusion
process. Medium size stars like the Sun can fuel themselves longer than smaller stars by
fusing helium into oxygen and carbon. Very large stars can continue the nuclear fusion
process much, much longer, making heavier elements like calcium and iron.
Small
Stars
Medium
Stars
(Sun)
Large
Stars
fuse
H
to
form
He
fuse
H
to
form
He
fuse
H
to
form
He
then
then
O
and
C
O
and
C
then
Ne, Na
Mg, S
Si
then
Really
Large
Stars
Ca
Fe
TEKS 8.8A describe components of the universe including stars, nebulae and galaxies, and use models such as the Herztsprung-Russell
diagram for classification
TEKS 8.8B recognize that the Sun is a medium-sized star near the edge of a disc-shaped galaxy of stars and that the Sun is many
thousands of times closer to the Earth than any other star
Stellar Fingerprints
Adapted from Region 4, Fingerprints of the Stars
Objectives:
 Describe the components of the universe (stars).
 Analyze and predict trends from data.
Procedures:
1. Look at the two sets of spectra patterns. Identify the elements present in each of the stars by
comparing the spectra of the stars to those of the elements.
2. Record the elements for each star in the data table by marking an “X” in the table.
3. Use the periodic table to find and record the atomic number and mass of each element in the
table.
Data Table:
Star Name
color & type
Elements Present in Star
H
He
Ca
Li
Na
Mg
Fe
Ne
Sun
yellow main
sequence
Procyon
white main
sequence
Betelgeuse
red super
giant
Sirius
white dwarf
Aldebaran
orange giant
Atomic
Number
Atomic
Mass
Questions:
1. The elements common to all of the stars are _________________________________
2. These elements are common to all of the stars because ________________________
____________________________________________________________________
3. The process in which stars produce energy is ________________________________
4. Based on the data, the most massive stars are probably _______________________
5. The least massive is ___________________________________________________
6. Which elements are produced by the massive stars? __________________________
7. What is a characteristic of the elements produced by the massive stars? ___________
8. Based on the elements present in the Sun and what you know about how stars produce
energy, what inferences can you make about the Sun? __________________
Spectral Patterns for Stars
Spectral Patterns of Elements