Star Types Quick Check
1 of 61 of 6 Items
Question
Use the diagram to answer the question.
The Hertzsprung-Russell Diagram is shown. The left y-axis is labeled luminosity and the right y-axis is labeled absolute magnitude. The bottom x-axis is labeled with temperature left parenthesis Kelvin right parenthesis. The temperatures along the bottom are 40,000, 20,000, 10,000, 7,500, 5,500, 4,500, and 3,000. The top x-axis is labeled spectral class. The spectral classes labeled along the top from left to right are O, B, A, F, G, K, and M. Spectral class O lines up with a temperature of 40,000 K. Spectral class B lines up with a temperature of 20,000 K. Spectral class A lines up with a temperature of 10,000 K. Spectral class F lines up with a temperature of 7,500 K. Spectral class G lines up with a temperature of 5,500 K. Spectral class K lines up with a temperature of 4,500 K. Spectral class M lines up with a temperature of 3,000 K. Stars of different luminosity, absolute magnitude, spectral classes, and temperatures are plotted on the graph. Red giants and supergiants are shown in the upper right quadrant, indicating lower temperatures. White dwarfs are shown in the lower left quadrant, indicating higher temperatures and lower luminosity. Different main sequence stars are shown, ranging from hot and bright in the upper left quadrant to cooler and dimmer in lower right quadrant.
Which spectral class does a star fit into if it has a surface temperature of 20,000 K?
(1 point)
Responses
M
M
G
G
B
B
A
The correct answer is B.
Can you please elaborate on why that is correct? Thanks!
Yes, I apologize for not providing an explanation earlier.
In the given diagram, the spectral class B is shown to have a temperature of 20,000 K. The spectral classes are labeled along the top x-axis and are arranged in order from hottest to coolest, with O being the hottest and M being the coolest.
Therefore, if a star has a surface temperature of 20,000 K, it would fall into the spectral class B.
Which of these properties is the best measure of a star's brightness?(1 point)
Responses
age
age
apparent magnitude
apparent magnitude
absolute magnitude
absolute magnitude
size
Is it age?
No, age is not the best measure of a star's brightness. The best measure of a star's brightness is the apparent magnitude.
Which of these phrases describes the sun?(1 point)
Responses
Class G yellow star
Class G yellow star
Class A white star
Class A white star
Class M red star
Class M red star
Class O blue star
is it class G yellow star?
Yes, the correct answer is "Class G yellow star" to describe the Sun.
Star Types Quick Check
4 of 64 of 6 Items
Question
Use the diagram to answer the question.
The Hertzsprung-Russell Diagram shows the spectral class of stars across the top, the temperature in Kellvin of stars across the bottom. The luminosity of stars, with the luminosity of the Sun equal to one, on the right, and the absolute magnitude of stars on the right. Blue giants, red supergiants, red giants, main sequence stars, the Sun, and white dwarfs are shown on the diagram.
Which type of star is in spectral class K and has a luminosity of 106?
(1 point)
Responses
red giant
red giant
red supergiant
red supergiant
blue giant
blue giant
white dwarf
The correct answer is "white dwarf".
How is the sun classified on an Hertzsprung-Russell Diagram?(1 point)
Responses
as a white dwarf star
as a white dwarf star
as a supergiant star
as a supergiant star
as a main sequence star
as a main sequence star
as a giant star
is it a giant star?