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# ← Unit 11 Stellar PropertiesTest

### Question Limit

of 52 available terms

### 5 Matching Questions

1. Optical Double
2. Spectroscopic Binary
3. Polaris
4. Variable Stars
5. Spectral type M
1. a Red - Temperature range <3,500 K.
2. b Spectral type F (pale yellow) Temperature range: 6,000-7,500 K.
3. c Stars not physically related to each other but happen to line up so that we see what appears to be a double star system. More rare than one would think.
4. d Two stars that are so close that the only way we can detect the binary nature is through a spectral (red) shift.
5. e Stars that appear to change in brightness.

### 5 Multiple Choice Questions

1. One of the two major classes of variables. There are five classes. One important example: Cepheid Variables.
2. Referred to as the H-R Diagram. Plots two stellar properties. The star's temperature (spectral class) and the star's Luminosity - measured either by solar units (against our Sun) or Absolute Magnitude.
3. Next closest after Proxima Centauri. 6 light years away. Next there are about 30 stars within 16.5 light years of earth.
4. Group of young, hot stars that are physically related by being held together by gravity. <50 -100> stars.
5. Orange - Temperature range: 3,500 - 5,000 K.

### 5 True/False Questions

1. Apparent MagnitudeBrightness if we moved all the stars to the same distance. 10 pc. (Comparing apples to apples)

2. Inverse Square LawIf we see a star at twice the distance, we see 1/4 the amount of light. If the star is at 10 times the distance, we would see 1/100 the amount of light.

3. Stellar EvolutionThe most important stellar property. Measured by an adaptation of Kepler's 3rd Law as derived by Sir Isaac Newton. Kepler's 3rd law you measure the period and average distance of the object's orbit. You need two objects. Over 50% of stars have a companion star.

4. Magnitude SystemMost stars, like our sun

5. Star ClustersGroup of young, hot stars that are physically related by being held together by gravity. <50 -100> stars.