The Spectrum of Stars in an Open Cluster Is Found

question 275

Multiple Choice

The spectrum of stars in an open cluster is found to contain spectral lines from many heavy elements; the stars are known as "metal-rich." What is the source of these heavy elements?

• A) fusion reactions on the very hot surfaces of these stars
• B) The heavy-element content of these stars is not enhanced but the hydrogen and helium content has been depleted by intense stellar winds made up preferentially of these light elements.
• C) fusion reactions in the star cores, carried to the surface by convection
• D) the interstellar medium, which originated in explosions of stars earlier in history that had manufactured heavy elements by nuclear fusion

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Definitions:

Stimulus Energy

The physical energy from the environment that impacts sensory organs, leading to perception.

Electromagnetic Energy

Refers to a form of energy that is reflected or emitted from objects in the form of electrical and magnetic waves that can travel through space.

Ultraviolet Light

A type of electromagnetic radiation with a wavelength shorter than that of visible light but longer than X-rays.

Absolute Threshold

The minimum intensity of a stimulus that one can detect 50% of the time.