Chapter 29 Stars

Which statement best describes stars?

• large planets that are composed mostly of gases

• celestial bodies made up of gas that give off light

• faint dots of light that can be seen from Earth’s surface

• objects that form in the outer parts of the solar system

What information does she need to calculate the absolute magnitude of a star?

• color and temperature of the star

• color and composition of the star

• apparent magnitude and distance from Earth of the star

• color and distance from Earth of the star

What characteristic of stars is measured by luminosity?

• brightness

• size

• temperature

• distance from Earth

Which of the stars listed in the table above would look the brightest when observed from Earth?

• Sirius

• Rigel

• Arcturus

• Aldebaran

Which star has the greatest luminosity?

• Sirius

• Rigel

• Arcturus

• Aldebaran

Based on the information in the table, which of these statements is true?

• Sirius and Arcturus appear blue when observed from Earth.

• When observed from Earth, Rigel and Betelgeuse appear the dimmest.

• Aldebaran, Rigel, and Betelgeuse have lower luminosity than Sirius, Vega, and Arcturus do.

• Sirius looks the brightest from Earth, but Rigel has the greatest luminosity.

Based on the graph, what conclusion can be drawn about the relationship between temperature and absolute magnitude?

• Absolute magnitude is not related to the temperature of a star.

• A hotter star has a greater absolute magnitude than a cooler star.

• There is an inverse relationship between temperature and absolute magnitude.

• Hotter stars will have a more positive value for absolute magnitude, which measures luminosity.

Based on the graph, a star of which color most likely has the lowest luminosity?

• red

• blue

• yellow

• white

Which of the following units is used to express the size of stars?

• kilometer

• light-year

• solar radius

• astronomical unit

Which of the following pairs of terms directly relates to the actual brightness of a star?

• absolute magnitude and luminosity

• apparent magnitude and luminosity

• size and luminosity

• absolute magnitude and apparent magnitude