GENERAL KNOWLEDGE

GK

THE UNIVERSE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
What information can we get about stars from their spectral lines?
A
their size
B
their names
C
chemical composition
D
the favorite food
Explanation: 

Detailed explanation-1: -This type of study is called spectroscopy. The science of spectroscopy is quite sophisticated. From spectral lines astronomers can determine not only the element, but the temperature and density of that element in the star. The spectral line also can tell us about any magnetic field of the star.

Detailed explanation-2: -Short answer: Hydrogen and helium (and tiny amounts of lithium). That’s it. Astronomers know that the first stars, officially known as Population III stars, must have been made almost solely of hydrogen and helium-the elements that formed as a direct result of the big bang.

Detailed explanation-3: -The primary reason that stellar spectra look different is because the stars have different temperatures. Most stars have nearly the same composition as the Sun, with only a few exceptions. Hydrogen, for example, is by far the most abundant element in most stars.

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