Chapter 21 - Section 2 - Characteristics of Stars Flashcards
constellation
An imaginary pattern of stars in the sky.
spectrograph
An instrument that separates light into colors and makes and image of the resulting spectrum.
What is a spectrograph?
a device that breaks light into colors and produces an image of the resulting spectrum
a graph used to classify stars and to understand how stars change
a tool used by astronomers to measure a star’s parallax
an instrument that measures a star’s absolute brightness
a device that breaks light into colors and produces and image of the resulting spectrum
apparent brightness
The brightness of a star as seen from Earth.
absolute brightness
The brightness a star would have if it were at a standard distance from Earth.
What is a star’s absolute brightness?
the change in the star’s position when viewed from different places
the distance between the star and Earth
the star’s brightness as seen from Earth
the brightness the star would have if it were at a standard distance from Earth
the brightness the star would have if it were at a standard distance from Earth.
How is a parallax useful in astronomy?
Parallax is directly related to a star’s temperature.
Parallax helps astronomers determine the chemical composition of stars.
Parallax shows the distance to very distant stars.
Astronomers often use parallax to measure distances to nearby stars.
Astronomers often use parallax to measure distances to nearby stars.
light-year
The distance that light travels in one year, about 9.5 million million kilometers.
parallax
The apparent change in position of an object when seen from different places.
Hertzsprung-Russel diagram
A graph relating the surface temperatures and absolute brightnesses of stars.
main sequence
A diagonal area on an H-R (Hertzsprung-Russell) diagram that includes more than 90 percent of all stars.
What is the main sequence?
the top of an H-R diagram, where the brightest stars are located
the bottom of an H-R diagram, where the dimmest stars are located
the diagonal area on an H-R diagram that includes more than 90 percent of all stars
the top center and right of an H-R diagram where giant and supergiant stars are found
the diagonal area on an H-R diagram that includes more than 90 percent of all stars
