Vocabulary 1
What is the magnitude of a celestial object as it would be seen at a distance of 10 parsecs.
Absolute magnitude
After exhausting its fuel, a low-mass star will shrink and become a dense, hot remnant known as a ______________.
White dwarf
What does H-R stand for?
Hertzsprung-Russell
What is a light-year?
distance light travels in one year
What are the inner planets in the solar system?
Mercury, Venus, Earth, and Mars
_____________ is the force responsible for keeping planets in orbit around stars.
Gravity
What is any star that has a large radius for its mass and temperature?
Giant star
Are blue stars hot or cold?
Hot
What is an astronomical unit?
An average distance from the Earth to the Sun
What are the outer planets in the solar system?
Jupiter, Saturn, Uranus, and Neptune
Spectral class
What is a measurement of radiated electromagnetic energy per unit time?
Luminosity
Are red stars hot or cold?
Cold
What do orbit calculations consider?
Mass, distance, and velocity
How many laws are in Kepler's Law?
3
The sun is a ______________ because it is in a stable place, fusing hydrogen into helium.
Main sequence star
Stars are classified into different groups based on their color and temperature, which is called their _________________.
Spectral class
Where are red stars and white dwarfs located on the H-R diagram?
Red giants are in the upper right because they are cool. White dwarfs are located in the lower left because they are hot.
What is Newton's law of gravitation?
F=G(M1 M2/r2)
Hydrogen and Helium
A star's brightness depends on both its distance and actual energy output, which is why scientists measure both __________________ and _________________.
Apparent magnitude, Absolute magnitude
Supergiant
What two main properties of stars does the H-R diagram show?
Luminosity and temperature
What does a red shift indicate?
Galaxies are moving away from us
Are outer planets large and gaseous or short and rocky?
Large and gaseous