stars - katy independent school districtstaff.katyisd.org/sites/0704733/documents/stars...studying...
TRANSCRIPT
![Page 1: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/1.jpg)
Stars
![Page 2: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/2.jpg)
Studying Stars
• Astronomers use a spectroscope to study
the movement of stars
• Blue shift – towards earth
• Red shift – away from earth
• Change in a wavelength moving toward or
away from earth is the Doppler Effect
![Page 3: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/3.jpg)
Galaxies Galore
• Types of Galaxies:
– Spiral – spinning wit “arms”
– Elliptical – roundish
– Irregular – no set pattern
• Star Clusters
– Open - apart
– Globular - together
![Page 4: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/4.jpg)
What is a star?
• The objects that produces heat and
light in solar systems
• A star is a ball of plasma held
together by its own gravity
– Nuclear reactions occur in stars (H
He)
– Energy from the nuclear reactions is
released as electromagnetic radiation
![Page 5: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/5.jpg)
Characteristics of Stars
• DISTANCE
– Measured in light-years
• The distance which a ray of light would
travel in one year
• About 6,000,000,000,000 (6 trillion) miles
• 186,000 miles per second
![Page 6: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/6.jpg)
Characteristics of Stars
• Magnitude (brightness)
– A measure of brightness of celestial
objects
• Smaller values represent brighter objects
– Apparent magnitude
• How bright a star appears to be from Earth
– Absolute magnitude (luminosity)
• How bright a star actually is
![Page 7: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/7.jpg)
Characteristics of Stars
http://www.seasky.org/cosmic/sky7a01.html
• Temperature & Color
– The color of a star indicates the Temp of
the star
– Stars are classified by Temp
• Decreasing Temp (bright to dim)
• O, B, A, F, G, K, M [Oh Be A Fine Girl, Kiss
Me ]
![Page 8: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/8.jpg)
Hertzsprung-Russell Diagram
http://www.dustbunny.com/afk/stars/lifecycle/hrdiagram.gif
![Page 9: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/9.jpg)
Main Sequence Stars
• A major grouping of stars that forms a
narrow band from the upper left to the
lower right when plotted according to
luminosity and surface temperature on the
Hertzsprung-Russell diagram
![Page 10: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/10.jpg)
Types of Stars
Classification
Class Temperature Color
O 20,000- 60,000 K Blue
B 10,000 – 30,000 K Blue-white
A 7,500 – 10,000 K White
F 6,000 – 7,500 K Yellow-white
G 5,000 – 6,000 K Yellow
K 3,500 – 5,000 K Orange
M 2,000 – 3,500 K Red
![Page 11: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/11.jpg)
http://www.answers.com/topic/stellar-classification
![Page 12: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/12.jpg)
Life Cycle of Stars
http://hea-www.cfa.harvard.edu/CHAMP/EDUCATION/PUBLIC/ICONS/life_cycles.jpg
![Page 13: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/13.jpg)
Life Cycle of Stars
• Begin their lives as clouds of dust and gas called nebulae
• Gravity may cause the nebula to contract
• Matter in the gas cloud will begin to condense into a dense region called a protostar
• The protostar continues to condense, it heats up. Eventually, it reaches a critical mass and nuclear fusion begins.
• Begins the main sequence phase of the star
• Most of its life is n this phase
![Page 14: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/14.jpg)
Life Cycle of Stars
Life span of a star depends on its size.
– Very large, massive stars burn their fuel much faster than smaller stars
– Their main sequence may last only a few hundred thousand years
– Smaller stars will live on for billions of years because they burn their fuel much more slowly
• Eventually, the star's fuel will begin to run out.
![Page 15: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/15.jpg)
Life Cycle of Stars
• It will expand into what is known as a red
giant
• Massive stars will become red supergiants
• This phase will last until the star exhausts
its remaining fuel
• At this point the star will collapse
![Page 16: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/16.jpg)
Life Cycle of Stars
• Most average stars will blow away their
outer atmospheres to form a planetary
nebula
• Their cores will remain behind and burn as
a white dwarf until they cool down
• What will be left is a dark ball of matter
known as a black dwarf
![Page 17: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/17.jpg)
Life Cycle of Stars
• If the star is massive enough, the collapse
will trigger a violent explosion known as a
supernova
• If the remaining mass of the star is about
1.4 times that of our Sun, the core is
unable to support itself and it will collapse
further to become a neutron star
![Page 18: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/18.jpg)
Life Cycle of Stars
• The matter inside the star will be
compressed so tightly that its atoms are
compacted into a dense shell of neutrons.
If the remaining mass of the star is more
than about three times that of the Sun, it
will collapse so completely that it will
literally disappear from the universe. What
is left behind is an intense region of gravity
called a black hole
![Page 19: Stars - Katy Independent School Districtstaff.katyisd.org/sites/0704733/Documents/Stars...Studying Stars •Astronomers use a spectroscope to study the movement of stars ... earth](https://reader034.vdocuments.net/reader034/viewer/2022050312/5f744b9fa9110973c23de3d3/html5/thumbnails/19.jpg)
Life Cycle of Stars
http://www.seasky.org/cosmic/sky7a01.html