Exploring the Universe. .The sun gives off tremendous amounts of energy in forms of electromagnetic...
If you can't read please download the document
Exploring the Universe. .The sun gives off tremendous amounts of energy in forms of electromagnetic radiation.The sun's interior consists of the core,the
.The sun gives off tremendous amounts of energy in forms of
electromagnetic radiation.The sun's interior consists of the
core,the radiation zone,and the convection zone.The suns atmosphere
consists of three layers: the photosphere, the chromosphere and the
coron.The sun's magnetic field produces striking features on and
above it surface ex: sunspots,prominences,and solar flares.The suns
mass is more than 300,000 x the mass of earth and its volume is
about 1,000,000 x that of earth THE SUN Core- Central region where
nuclear fusion occurs. Radiation zone- a region of highly
compressed gas. Convection zone- The outer layer or the suns
interior Photosphere- 500 kilometers thick and has an average
temperature of about 5800 K. Chromosphere- Middle layer of the
sun's atmosphere. Corona-The outermost layer of the sun.
Solarwinds- a stream of electrically charged particles that flow
outwards from the sun. Sunsports- area of gas in the photosphere
that are cooler than the surrounding gases. prominences- huge loops
of gas that erupt from sunspot region. Solar flare-Sudden release
of energy from the sun usually occur near sunspots.
Slide 3
The sun The Corona
Slide 4
Stars. A large glowing ball of gas in space. A star generates
its energy through nuclear fusion in its core,the coolest star to
earth is the sun.Stars are so far apart that astronomers use larger
units,including the light-year.various methods have been created
just to determine the distance of stars.Due to the
telescope,astronomers can now measure the distance of stars with
greater accuracy.Stars are classified by color size,brightness
other properties are mass and chemical compositions.Astronomers can
estimate the diameter and volume of a star by the star's
temperature by absolute brightness.Hertzsprung-Russell Diagram or
(H-R) are used to estimate the size of stars and their distance to
infer how stars change over time Star- Is a large,glowing ball of
gas in space which generates through nuclear fusion in its core.
Light-Year-Is the distance that light travels in a vacuum in a
year, which is about 9.5 trillion kilometers. Parallax- The
apparent change in position of an object with respect to a distant
background. Apparent brightness- The brightness of a star as it
appears from earth. Absolute brightness- is how bright a star
really is. Absorption lines- Show where light has been absorbed.
H-R diagram- Is a graph of the surface temperature,or,color, and
absolute brightness. Main sequence- Astronomers call this diagonal
band on the H-R diagram. Supergiants- The very bright stars at the
upper right of the H-R diagrams. Giants-Bright stars that are
smaller and fainter than supergiant. White Dwarfs-Small dense
remains of low or medium mass stars..
Slide 5
Slide 6
Life Cycles of Stars.A star is formed when a contracting cloud
of gas and dust becomes so dense and hot that nuclear fusion
begin.A star's mass determines the stars place on the main sequence
and how long it will stay.The dwindling supply of fuel in a stars
core ultimately leads to the stars death as a white dwarf, neutron
star, or black hole Nebula- Is a large cloud of gas and dust spread
out over a large volume of space. Protostar- A contracting cloud of
gas and dust with enough mass to form a star. Planetary nebula- The
dying star surrounded by a glowing cloud of gas. Supernova- An
explosion so violent that the dying star becomes more brilliant
than an entire galaxy. Neutron star- Is the dense remnant of a
high-mass star that has exploded as a supernova. pulsar-A spinning
neutron star that appears to gives off strong pulses of radio
waves. Black Hole-Is an object whose surface gravity is so great
that even electromagnetic waves traveling at the speed of
light.
Slide 7
Rosette Nebula
Slide 8
Groups of Stars.Astronomers have determined that more than half
of gas and dust becomes so dense and hot nuclear fusion begin.There
are three basic kinds of star clusters: open,association and
globular clusters.Astronomers classify galaxies into four main
types, spiral, barred-spiral, elliptical and irregular
Constellation- group of stars that appears to form a pattern. Star
System- A group of two or more stars that are held together by
gravity. Binary system-A star system with two stars. Globular
Cluster- A large group of older stars. Galaxy- A huge group of
individual stars, star systems, star cluster,dust, and gas bound
together by gravity. Spiral Galaxies- Have a bulge of stars at the
center, Milky Way. Barred spiral galaxies- Have a bar through the
center with the arms extending outward from the bar on either side.
Elliptical galaxies- are spherical or oval, with no trace of spiral
arms.
Slide 9
Open Clusters Spiral Galaxies
Slide 10
The Expanding Universe.The observed red shift in the spectra of
galaxies shows that the universe is expanding.Astronomers theorize
that the universe came into being at a single moment in a event
called the big bang.The existence of cosmic microwave background
radiation and the red shift in the spectra of distant galaxies
strongly support the big bang theory.Dark matter cannot be seen
directly,but its presence can be detected by observing its
gravitational effects on visible matter.Dark energy is theorized to
be causing the rate of expansion to increase.If the expansion is
accelerating, its likely that the universe will expand forever Red
shift- the light of galaxies is shifted towards the red wavelengths
Hubble's law-the speed at which a galaxy is moving is proportional
to its distance from us Big bang Theory- states that the universe
began in an instant, billions of years ago, in an enormous
explosion Dark Matter- matter that does not give off radiation