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WorksheetsLUMINOSITY
Total questions: 12
Worksheet time: 8mins
Which star's colour is invisible in space by the human eyes?
Red Star
Yellow Star
Green Star
Orange Star
Choose the correct explanation(s)
Blue stars are actually colder than red stars. Their low temperature makes them have a chilly environment which results in an outward blue colour.
As the star gets hotter, the wavelength will decrease and moves further to the left, the ultraviolet end of the spectrum. Thus, bluer stars which are on the left of the spectrum are hotter than red stars.
Blue stars are hotter than hot stars because they generally have a greater mass. This means that they have more energy to burn up for fusion in the core, resulting in higher temperatures than red stars.
None of the above
The luminosity of the Sun, 𝐿𝐿⨀, is 3.828∗1026W. Polaris has a mass of 7.5𝑀𝑀⨀and a diameter 30 times that of the Sun. The difference between their absolute magnitudes is 8.47. What is the surface temperature on Polaris?
7600K
7400K
7200K
7000K
6800K
Which celestial body above is most likely to have the highest surface temperature?
A
B
C
D
Which of the following stellar spectral classes has the highest surface temperature?
O
A
F
K
Which of the following is the best approximate ratio of the brightness of a magnitude 1 star, to that of a
magnitude 3 star?
2
4
631/100
100/631
Is the star marked X belong to the main sequence stars?
True
False
Which pair is most likely to have stars with approximately equal radii?
A
B
C
D
It is impossible to compare stellar radii using a H–R diagram.
What kind of star has the longest lifespan?
A very massive star, like a blue giant
An average sized star, like our Sun
A star with low mass, like a red dwarf
Which of the following give off infrared radiation?
people
light bulbs
stars
a heated / glowing stovetop burner
In the simulation, as you go from low temperature objects (like the Earth) to high temperature objects (like the star Sirius A), what happens to the color produced?
It transitions from not emitting light, to emitting red light, then yellow, green, and lastly violet / blue.
It transitions from emitting blue light (the Earth), to emitting red light, then yellow, and lastly violet / blue.
Objects go from being blue to green to red as they heat up.
