Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 19: Problem 16

Explain how and why the turnoff point on the H-R diagram of a cluster is related to the cluster's age.

Short Answer

Expert verified
The turnoff point on the H-R diagram of a cluster relates to the cluster's age as it signifies where stars of a certain mass and thus age, are leaving the main sequence due to hydrogen fuel exhaustion in their cores. The mass of stars at the turnoff point signals the age of the cluster – high-mass indicates a young cluster while low-mass suggests an older cluster.

Step by step solution

01

Define the Hertzsprung-Russell (H-R) Diagram

Firstly, the Hertzsprung-Russell diagram or H-R diagram, is a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their spectral classifications or classifications. It's a tool that astronomers use to understand stellar evolution and categorization.
02

Explain the 'Turnoff Point'

In the context of an H-R diagram, the 'turnoff point' is the location on the main sequence where stars are just beginning to leave or turn off the main sequence. This happens because as a star reaches the end of its life span, it exhausts the hydrogen fuel in its core, and begins to evolve off the main sequence.
03

Describe the Aging Process

For a specific cluster, all the stars are roughly the same age, as they all formed from the same interstellar cloud. Hence, stars with higher masses, which evolve faster, will leave the main sequence before stars with lower masses. This creates a turnoff point on the H-R diagram from the main sequence over time.
04

Relating the Turnoff Point to a Cluster's Age

By observing the mass of the stars at the turnoff point (those which are just leaving the main sequence), the age of the cluster can be estimated. Heavier stars leave the main sequence faster, so a high-mass turnoff point indicates a young cluster, while a low-mass turnoff point indicates an older cluster. Thus, the turnoff point on the H-R diagram of a cluster is directly related to the cluster's age.
05

Final Summary

In conclusion, the turnoff point in the H-R diagram is a significant factor used to determine the age of a star cluster. By observing the mass of stars at that point, astronomers can tell if the cluster is older or younger.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Why does a star's luminosity decrease after helium fusion begins in its core?

What is the difference between Population I and Population II stars? In what sense can the stars of one population be regarded as the "children" of the other population?

What is the difference between a detached binary, a semidetached binary, a contact binary, and an overcontact binary?

The stars that make up the binary system W Ursae Majoris (see Figure 19-21c) have particularly strong magnetic fields. Explain how astronomers could have discovered this. (Hint: See Section 16-9.)

The Sun has increased in radius by \(6 \%\) over the past \(4.56\) billion years. Its present-day radius is \(696,000 \mathrm{~km}\). What was its radius \(4.56\) billion years ago? (Hint: The answer is not \(654,000 \mathrm{~km}\).)
See all solutions

Recommended explanations on Physics Textbooks

Conservation of Energy and Momentum

Read Explanation

Oscillations

Read Explanation

Fields in Physics

Read Explanation

Fundamentals of Physics

Read Explanation

Waves Physics

Read Explanation

Electricity

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free