# Astronomy college course/Introduction to stellar measurements/questions/Original version of this quiz

## Questions based on Introduction to Stellar Measurements

1 Stellar parallax is

 an annual change in angular position of a star as seen from Earth an astronomical object with known luminosity. the total amount of energy emitted per unit time. a numerical measure of brightness as seen from Earth a numerical measure of brightness as seen from a distance of approximately 33 light-years

2 Luminosity is

 an annual change in angular position of a star as seen from Earth an astronomical object with known luminosity. the total amount of energy emitted per unit time. a numerical measure of brightness as seen from Earth a numerical measure of brightness as seen from a distance of approximately 33 light-years

3 A standard candle is

 an annual change in angular position of a star as seen from Earth an astronomical object with known luminosity. the total amount of energy emitted per unit time. a numerical measure of brightness as seen from Earth a numerical measure of brightness as seen from a distance of approximately 33 light-years

4 Absolute magnitude is

 an annual change in angular position of a star as seen from Earth an astronomical object with known luminosity. the total amount of energy emitted per unit time. a numerical measure of brightness as seen from Earth a numerical measure of brightness as seen from a distance of approximately 33 light-years

5 Relative magnitude is

 an annual change in angular position of a star as seen from Earth an astronomical object with known luminosity. the total amount of energy emitted per unit time. a numerical measure of brightness as seen from Earth a numerical measure of brightness as seen from a distance of approximately 33 light-years

6 In 1989 the satellite Hipparcos was launched primarily for obtaining parallaxes and proper motions allowing measurements of stellar parallax for stars up to about 500 parsecs away, which is about ____ times the diameter of the Milky Way Galaxy.

 0.015 0.15 1.5 15 150

7 An object emits thermal (blackbody) radiation with a peak wavelength of 250nm. How does its temperature compare with the Sun?

 The temperature is the same 2 times colder than the Sun 2 times hotter than the Sun 5 times colder than the Sun 5 times hotter than the Sun

8 The "normalized intensity" of a Sun-like star situated one parsec from Earth would be 4πI = 1. What is 4πI for a star with 100 times the Sun's energy output that is situated 10pc from Earth?

 10-2 10-3 10-1 10-4 1

9 An orbiting satellite makes a circular orbit 5 AU from the Sun. It measures a parallax angle of 0.2 of an arcsecond (each way from the average position). What is the star's distance?

 10 parsecs 25 parsecs 5 parsecs 1 parsec 50 parsecs

10 A star that is increasing it's temperature while maintaining constant luminosity is

 getting smaller in size turning red in the process of dying on the verge of becoming a supernovae e) getting larger in size

11 The range of wavelength for visible light is between

 400 and 700 nanometers 1 and 10 nanometers 600 and 1200 nanometers 0.1 and 10 nanometers 5000 and 6000 nanometers

12 Based on the HR diagrams and images in stars shown in the materials, a very large red supergiant has a diameter that is about ____ greater than a small white dwarf.

 3x103 3x109 3x1011 3x107 3x105