THE UNIVERSE

Trotter 2014

IV. The Sun A. All life on Earth depends on the energy that

comes from the star in the center of our solar system.

B. Energy produced by the Sun is due to hydrogen atoms fusing together to produce helium atoms.

C. The Sun is composed of 3 layers: 1. Photosphere – innermost not as hot 2. Chromosphere – transition zone 3. Corona – largest & hottest layer

V. Sun Surface Features A. The sun appears to

be a smooth layer but has many surface features including: 1. Sun spots – cooler

areas 2. Prominences – arching

columns of gas 3. Flares – gases

shooting straight upward 4. CMEs (coronal mass

ejections) – auroras All due to magnetic field & reactions across the Sun.

Solar Flares

The sun unleashed a powerful solar flare late Monday (Oct. 22), releasing waves of radiation into space that have already caused a short radio blackout on

Solar flares are caused when magnetic activity ramps up in certain patches, called sunspots, on the surface of our sun

Auroras

Solar Eclipse

Occurs when the Sun, Moon, and Earth line up

Can only happen during a New Moon

Generally, they occur every 2-5 years

Lunar Ecipse

Occurs during a Full Moon

Occurs when Moon, Earth, and Sun are directly aligned.

Next one is October 8, 2014

Sun Cycle

Cycle lasts about every 11 years

Done so by counting sunspots

Sunspots may exist anywhere from a few days to a few months, but they eventually decay, and this releases magnetic flux in the solar photosphere

I. Constellations

A. Constellations are patterns of stars that are named as a group. (88 exist in our sky)

B. All the constellations we see in the sky are part of our galaxy (large collection of stars, gas, & dust held together by gravity), the Milky Way Galaxy

II. Absolute & Apparent Magnitude

A. The actual brightness of the star refers to the stars absolute magnitude.

B. How bright the star actually is to the viewer on Earth is called the apparent magnitude Apparent Magnitude does not equal absolute

magnitutde

III. Measuring in Space A. Distance in space is measure in light years

or the distance light travels in one year (9.5 trillion km) Used to estimate the distance of stars from Earth The distance shifts depending on the

motion/position of Earth as it orbits (parallax)

Astronomical Unit: the distance between the Earth and the Sun

149 597 871 kilometers

VI. Properties of Stars

A. Basic properties of stars include: 1. Diameter 2. Mass 3. Brightness 4. Energy Output (luminosity) 5. Composition – 73% hydrogen, 25% helium 6. Surface Temperature – appears different due to

very slight composition differences

VII. Classifying Stars A. Hertzsprung & Russell Diagram shows the

relationship of temperature & brightness among stars

B. Main Sequence(90%) vs. Dwarfs & Giants (bright)

Temperature: x axis Absolute Magnitude: y axis

IIX. Life of a Star Scientists theorize that a star goes through a

few steps (as hydrogen depletes) 1. Nebula – ball of gas & dust 2. Main sequence – pieces of nebula are pulled

together due to gravity, force increases energy/temperature

3. Red Giant vs. Red Super Giant – when hydrogen begins to deplete outer layer cools & expands, (if large sequence is more quick & violent)

4. White Dwarf vs. Neutron Star or Black hole – outer layers cool & escape to space leaving hot dense core

Star Vocab

Binary star Parallax H-R Diagram Stellar nebula Massive star Red supergiant Red giant Planetary nebula Supernova White dwarf Neutron star Black hole Absolute magnitude Apparent magnitude

Classwork Activity

Star Cycle Flip Book or Comic Strip Must include all aspects of the star cycle For each step, there must be accurate

vocabulary and a small narrative describing what happens

Students will be graded on vocabulary, narratives and aesthetics

This should be turned in by the end of the week in order to remain on track (2/22/2014)

We are now here

Life cycle of our sun

They discovered that stars grouped by type and during their lifetimes would move from one place on the graph to another. As our sun ages, it will move to a giant star to a white dwarf.

IX. Galaxies

A. Galaxies are groups into clusters. B. Types of galaxies:

1. Spiral Galaxies 2. Elliptical Galaxies – football 3. Irregular Galaxies – small irregular

X. Gravitational Pull

A. Every 2 bodies in the universe attract each other with a force that is proportional to the product of their masses.

In other words gravitational force depends on their masses & the distance between the 2 bodies

Gravity increase with larger mass & closer proximityThink about 2 magnets