21st Century Astronomy
21st Century Astronomy
6th Edition
ISBN: 9780393428063
Author: Kay
Publisher: NORTON
bartleby

Concept explainers

Question
Book Icon
Chapter 20, Problem 1QP
To determine

The size of the Milky Way is determined from studying stars in globular clusters.

Expert Solution & Answer
Check Mark

Answer to Problem 1QP

Option (c) RR Lyrae is the correct option.

Explanation of Solution

A globular cluster is a spherical collection of stars that orbits a galactic core. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes, and relatively high stellar densities toward their centers.

RR Lyrae stars are easy to spot in globular clusters because they are relatively luminous and have a distinctive light curve. They lie in the instability strip of the Hertzsprung-Russell (H-R) diagram and suffer instabilities that cause their size to periodically change. This change in size also changes the temperature of the star giving rise to their variability.

The size of the Milky Way is determined from studying RR Lyrae stars in globular clusters.

Conclusion:

Since the period-luminosity relationship to determine the distances to globular clusters, option (c) is correct.

RR Lyrae is easy to spot in the globular cluster than the Cepheid variable. Thus, option (a) is incorrect.

Blue supergiant are found towards the top left of H-R diagram. Thus, option (b) is incorrect.

The density of stars inside a globular cluster is significantly higher than the density of stars around the Sun. Thus, option (d) is incorrect.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
suggest a reason ultrasound cleaning is better than cleaning by hand?
Checkpoint 4 The figure shows four orientations of an electric di- pole in an external electric field. Rank the orienta- tions according to (a) the magnitude of the torque on the dipole and (b) the potential energy of the di- pole, greatest first. (1) (2) E (4)
What is integrated science. What is fractional distillation What is simple distillation
Knowledge Booster
Background pattern image
Physics
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
An Introduction to Physical Science
Physics
ISBN:9781305079137
Author:James Shipman, Jerry D. Wilson, Charles A. Higgins, Omar Torres
Publisher:Cengage Learning
Text book image
Horizons: Exploring the Universe (MindTap Course ...
Physics
ISBN:9781305960961
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Text book image
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Text book image
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning