26.1 The Sun
The process that the sun uses to produce energy in the form of electromagnetic radiation.
Nuclear fusion.
The distance between stars is typically measured in this unit of distance equaling 9.5 trillion kilometers.
Light year.
This is the cloud of dust and gas spread out over a large region of space.
Nebula.
A group of Stars that form a pattern to observers on earth is called what?
A constellation.
This theory states that the universe came into existence during an enormous instantaneous explosion.
The Big Bang Theory
The primary fuel source for the majority of main sequence stars.
Hydrogen
Astronomers utilize this property of stellar objects to measure the distance of an object from earth.
Parallax
90% of a star's lifetime is spent on this diagonal band of planets that run from the top left to the bottom right of a Hertzsprung-Russell (H-R diagram) that relates size, temperature and brightness.
Main Sequence
Constellations are important as they were and can still be used for this purpose.
Navigation or Mapping
This stuff does not give off any heat or light, but scientists are still able to detect its existence, even if they don't know much more about it.
Dark Matter
The Sun and other stars are kept stable by the equilibrium of these two forces.
Thermal Pressure and gravity.
While many elements are believed to have originated from stars, the most common chemical composition for stars are of these elements.
Hydrogen and Helium
When nuclear fusion begins in the core of the protostar.
Large groupings of older stars are known as what type of star system?
Gloubular clusters.
What do we call the residual heat left over in the universe, often called the echo of the big bang. This residual heat is consistent throughout the universe and often used as evidence to support the big bang theory.
Cosmic Microwave Background Radiation
List each layer of the Sun's atmosphere.
Photosphere, Chromosphere, Corona
The chemical composition of a star can be identified by using this characteristic feature of the star's light.
What a star becomes when fusion ends in its core (the star dies), is dependent on its mass. What are the three possible end stages of Stars?
White Dwarf, Neutron Star, Black Hole
Associations and open clusters are similar in that they typically contain bright young stars; however, they differ because of what reason?
Associations are larger than open cluster (And are also temporary, not yet sorted out by gravity.)
The change in wavelength and frequency of light and sound of a moving object relative to a stationary observer is known as what?
The Doppler Effect
Three common features are present on or about the sun's surface, list each one and describe how they are distinct.
Sunspots - cool areas of gas formed from convective currents
Prominence - Huge loops of heated gas erupting from the edges of sunspots and shaped by the sun's magnetic forces.
Solar Flares - Eruption near sunspots of Charged Particles and X-rays into the universe.
The Hertzsprung-Russell or H-R diagram is a chart displaying the relationship between these three star characteristics.
Star Color/Temperature
Star Size
Star Absolute Brightness/Luminosity
From the very beginning, describe a low-medium mass star at each major phase of its lifespan - identify each form the star takes from birth to death.
(Nebula), Protostar, Main Sequence, Planetary Nebula, White Dwarf, (Black Dwarf)
Identify each of the 4 types of galaxies we discussed in class and explain what makes them distinct from one another.
Spiral - Many stars at the center with gas and dust in pinwheel arms extending outward.
Barred Spiral - Like Spiral but with a bar through the center with arms extending out on either side.
Elliptical - Large spherical galaxy with no arms and mostly old stars.
Irregular - Many young stars with disorganized appearance.
This law states that the speed at which a galaxy moves away from us is proportional to its distance from us.
Hubble's Law