Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
7 Cards in this Set
- Front
- Back
|
Describe how astronomers determine the composition, temperature, and brightness of the stars. |
They use a spectrograph - a device used to separate light into different colors or wavelengths. Because differentelements absorbdifferent wavelengths oflight, scientists candetermine the elementsthat make up a star bystudying its spectrum. |
|
|
Describe and give examples of types of stars motions. |
apparent motion- motion visible to the unaided eye, which is caused by the movement of the earth Circumpolar Stars- Stars that are always visible in the night sky and appear to be circling the north star Actual Motion- can rotate on an axis, revolve around one another, or move away or toward our solar system |
|
|
explain the difference between absolute and apparent magnitude |
apparent magnitude- the brightness of a star as seen from the earth Absolute Magnitude- the brightness that a star would have at a distance of 32.6 light years from earth |
|
|
Describe how a protostar becomes a star. |
When its temperature becomes 10 mill. nuclear fusion begins and a star is born |
|
|
Explain how a main sequence of a star generates energy. |
by nuclear fusion, converting hydrogen to helium in its core
|
|
|
Constellation |
a group of stars organized in recognizable pattern |
|
|
Describe 3 types of galaxies |
Spiral- a star group with a nucleus of bright stars and arms containing young stars Elliptical- a star group elongated in shape Irregular- a star group of no particular shape, rich in dust and gas |
