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What is the meaning of the term parallax in the context of measuring distance and motion?

• The apparent shift of a nearby star due to Earth's orbit
• The motion of a star toward or away from us
• The distance where parallax equals 1 arcsecond
• The change in wavelength due to motion

What is defined as a parsec?

• A distance of approximately 10 light-years
• The distance where parallax = 1 arcsecond (approximately 3.26 light-years)
• The measurement of distance using radio waves
• The region where pulsating variable stars are found

What is the purpose of radar ranging in astronomy?

• Measuring motion toward or away from Earth
• Classifying stars by temperature
• Measuring distance using radio waves within the solar system
• Mapping the ionized hydrogen around hot stars

In the study of stellar motion, what does radial velocity describe?

• The apparent shift of a star's position
• The rotation speed of an accretion disk
• Motion toward or away from us
• The speed of light through the interstellar medium

What does a Doppler shift indicate regarding a star's motion?

• A change in brightness over time
• A wavelength change due to motion, where red is away and blue is toward
• The true energy output of a star
• The classification of a star into spectral classes

How is apparent magnitude defined?

• The true energy output of a star
• How bright a star looks from Earth
• The brightness of a star at a distance of 10 parsecs
• A plot of brightness versus time

What does absolute magnitude measure?

• A star's brightness at 10 parsecs
• The apparent brightness of a star from Earth
• The temperature of a star's core
• The density of a molecular cloud

What is intrinsic luminosity?

• The apparent shift of a star
• The ionized hydrogen surrounding a star
• A star's true energy output
• The brightness change over a period of time

What information does a light curve provide?

• A comparison of temperature and size
• A classification of spectral types
• A measurement of brightness vs. time
• A map of the interstellar medium

What is the basis for a star's spectral class?

• Its distance from the solar system
• Its classification by temperature (OBAFGKM)
• The density of its accretion disk
• The amount of ionized hydrogen present