Stars and Stellar Spectra Quiz

Questions and Answers

What unit do astronomers use to measure the temperature of stars?

Kelvin

What is the tool used to categorize and sort stars based on their spectra?

Stellar classification

What process fuels stars in their cores?

Nuclear fusion reactions

What will our sun expand into closer to the end of its life?

Red giant Signup and view all the answers

What is the impact of the size of a star on the nuclear fusion process in its core?

The larger the star, the faster the nuclear fusion process happens Signup and view all the answers

What is the relationship between the temperature of a star and its wavelength?

The greater the temperature, the shorter the wavelength Signup and view all the answers

How do astronomers determine the temperature of a star?

By determining the wavelength of light emitted by the star Signup and view all the answers

Which category of stars emits the most energy and has the shortest wavelength?

Category O Signup and view all the answers

What type of light do moderately intense stars emit?

Yellow or white light Signup and view all the answers

How does the intensity of a star affect its emitted energy and wavelength?

Less intense stars emit less energy and have a longer wavelength Signup and view all the answers

What is the temperature range, in degrees Celsius, for stars mentioned in the text?

2,226 to 49,726 Signup and view all the answers

What is the category of stars cooler than 2500 degrees?

L Signup and view all the answers

What type of energy do hotter stars emit, according to the text?

Shorter wavelength energy Signup and view all the answers

What does Wien's Law state about the energy emitted by an object as its temperature increases?

Shifts towards a shorter wavelength Signup and view all the answers

How do astronomers categorize stars based on temperature?

O, B, A, F, G, K, M, and L Signup and view all the answers

Study Notes

Understanding Stars and Spectra

Stars can have a temperature range from 2500 Kelvin to 50,000 Kelvin, which is equivalent to 2,226 to 49,726 degrees Celsius and 4,040 to 89,540 degrees Fahrenheit.
The hottest temperature ever recorded on Earth's surface is 56.7 degrees Celsius or 134 degrees Fahrenheit in Death Valley, California, making stars' heat seem unimaginable.
Astronomers categorize stars using stellar spectra, with categories O, B, A, F, G, K, M, and L, based on temperature, where O-class stars are the hottest and M-class stars are the coolest.
Brown dwarfs, cooler than 2500 degrees, are in a category called L, but they are not hot enough for fusion reactions and are not technically stars.
The sun is a class-G yellow dwarf star with a surface temperature of about 5800 K.
Spectra is the categorization of all light, including visible and non-visible electromagnetic energy, and it measures photon intensity to determine a star's temperature, density, and chemical composition.
Hotter and brighter stars burn hydrogen at a rapid pace, increasing temperature and resulting in greater recorded photon intensity.
Wavelength and frequency determine a star's energy output and visible color, with shorter wavelengths having higher frequencies and shorter wavelengths emitting blue light.
A blackbody curve, based on Wien's Law, represents wavelength and intensity to determine a star's temperature and the type of energy it emits.
Wien's Law states that as temperature increases, the energy emitted by an object shifts towards a shorter wavelength, making hotter objects appear blue and cooler ones trend red.
Blackbody curves visually represent temperature differences of stars and the type of energy they emit, with hotter stars emitting shorter wavelength energy and cooler stars emitting longer wavelength energy.
Wien's Law asserts that the maximum emitted wavelength of any stellar body is inversely proportional to its absolute temperature, explaining why hotter objects appear blue and cooler ones trend red.