The Age of a Cluster of Stars Can Be Judged

question 148

Multiple Choice

The age of a cluster of stars can be judged by the

• A) amount of radioactive elements detected on the surfaces of its stars.
• B) turnoff point on the main sequence of its Hertzsprung-Russell diagram.
• C) total number of stars within the cluster.
• D) number of novae per year occurring within the cluster.

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Definitions:

Adiponectin

A protein hormone produced and secreted by adipose cells that regulates glucose levels as well as fatty acid breakdown.

Calcitonin

A hormone secreted by the thyroid gland that rapidly lowers the calcium content in the blood.

Oxytocin

Hormone secreted by the hypothalamus and released by the posterior lobe of the pituitary gland; stimulates contraction of the pregnant uterus and the ducts of mammary glands.

Suprachiasmatic Nucleus

Main biological clock; located in the hypothalamus. Important in setting circadian rhythms.