Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 17: Problem 8

Why is the magnitude scale called a "backward" scale? What is the difference between apparent magnitude and absolute magnitude?

Short Answer

Expert verified
The magnitude scale is called a 'backward' scale because the brighter a celestial object is, the lower its assigned numerical value. Apparent magnitude measures how bright a celestial object appears from Earth and can be influenced by distance and intervening matter. Absolute magnitude, on the other hand, denotes the intrinsic brightness of an object; its value indicates how bright the object would appear if it were situated 10 parsecs away from the observer.

Step by step solution

01

Understanding the Magnitude Scale

The magnitude scale is a logarithmic scale used to quantify the brightness of celestial objects. It is called a \"backwards\" scale because the brighter an object is, the lower its numerical value. For example, an object with a magnitude of 1 is much brighter than an object with a magnitude of 6.
02

Identifying Apparent Magnitude

Apparent magnitude is a measure of how bright a celestial object appears from Earth. It is subject to variability based on distance and intervening matter. If two celestial bodies have the same apparent magnitude, it means they appear to have the same brightness from Earth, irrespective of their actual luminosities or distances from Earth.
03

Identifying Absolute Magnitude

Absolute magnitude refers to the inherent brightness of a celestial object. It is the brightness that an object would have if it were placed 10 parsecs (about 32.6 light years) away from the observer. When comparing absolute magnitudes of celestial bodies, the one with the lower absolute magnitude is intrinsically brighter.

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

If a red star and a blue star both have the same radius and both appear equally bright, which one is farther from Earth? Explain why.

The star HD 3651 shown in Figure 17-13 has a mass of \(0.79 \mathrm{M}_{\odot}\). Its brown dwarf companion, HD \(3651 \mathrm{~B}\), has about 40 times the mass of Jupiter. The average distance between the two stars is about \(480 \mathrm{AU}\). How long does it take the two stars to complete one orbit around each other?

The solar constant, equal to \(1370 \mathrm{~W} / \mathrm{m}^{2}\), is the amount of light energy from the Sun that falls on 1 square meter of the Earth's surface in 1 second (see Section 17-2). What would the distance between the Earth and the Sun have to be in order for the solar constant to be 1 watt per square meter \(\left(1 \mathrm{~W} / \mathrm{m}^{2}\right)\) ?

Suppose two stars have the same apparent brightness, but one star is 8 times farther away than the other. What is the ratio of their luminosities? Which one is more luminous, the closer star or the farther star?

As seen from the starship Enterprise in the Star Trek television series and movies, stars appear to move across the sky due to the starship's motion. How fast would the Enterprise have to move in order for a star \(1 \mathrm{pc}\) away to appear to move \(1^{\circ}\) per second? (Hint: The speed of the star as seen from the Enterprise is the same as the speed of the Enterprise relative to the star.) How does this compare with the speed of light? Do you think the stars appear to move as seen from an orbiting space shuttle, which moves at about \(8 \mathrm{~km} / \mathrm{s}\) ?
See all solutions

Recommended explanations on Physics Textbooks

Modern Physics

Read Explanation

Fluids

Read Explanation

Oscillations

Read Explanation

Famous Physicists

Read Explanation

Measurements

Read Explanation

Medical Physics

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