An Astronomer Plots the H-R Diagram of a Star Cluster

question 218

Multiple Choice

An astronomer plots the H-R diagram of a star cluster and finds that it contains hot B-type stars on the main sequence and cooler G- and K-type stars noticeably above the main sequence. This cluster is

• A) of indeterminate age since the age of the cluster cannot be estimated from the information given.
• B) impossible because cool stars cannot be above the main sequence when hot stars are on the main sequence.
• C) old because the G and K stars are already evolving off (away from) the main sequence.
• D) very young because the G and K stars are still evolving toward the main sequence.

---

Definitions:

Title Bar

The title bar is the top section of a window in a graphical user interface that displays the title of the application or document open in the window.

HTML Tag

A snippet of code that tells a web browser how to display a portion of the text or how to execute something on a webpage.

Applet Class

In Java, it refers to a small application designed to be transmitted over the internet and executed by a Java-compatible web browser.

JApplet

A Java class for creating applets, which are small applications designed to run within a web browser or applet viewer.