Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 8: Problem 26

What is microlensing? How does it enable astronomers to discover extrasolar planets?

Short Answer

Expert verified
Microlensing is a phenomenon where the gravitational field of a star magnifies the light of a distant star. It helps astronomers discover extrasolar planets because an observable anomaly in the light curve caused by the planet's gravitational field indicates the presence of the planet. Microlensing facilitates the detection of distant and low-mass extrasolar planets.

Step by step solution

01

Understand Microlensing

Microlensing occurs when the gravitational field of a star acts like a lens, magnifying the light of a distant background star. This is based on Albert Einstein's theory of General Relativity which states that massive objects cause a distortion in space-time, which is experienced as gravity.
02

Identify the Role of Microlensing in Discovering Extrasolar Planets

Microlensing helps in the discovery of extrasolar planets or exoplanets. When a lensing star has a planet orbiting it, the planet's gravitational field can affect the light from the background star, resulting in a detectable anomaly in the light curve. This anomaly in the light curve due to the planet help astronomers discover the planet even when they are far from Earth.
03

Explain the Advantage of Microlensing

Microlensing has a crucial advantage in the field of astronomy. Unlike the traditional planet-hunting methods, microlensing can detect distant planets that other methods would miss. It can also identify low-mass planets that orbit relatively far from their stars.

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 are terrestrial planets smaller than Jovian planets?

The planet discovered orbiting the star 70 Virginis (" \(70 \mathrm{Vir}\) " in Figure 8-17), 59 light-years from Earth, moves in an orbit with semimajor axis \(0.48 \mathrm{AU}\) and eccentricity \(0.40\). The period of the orbit is \(116.7\) days. Find the mass of 70 Virginis. Compare your answer with the mass of the Sun. (Hint: The planet has far less mass than the star.)

Because of the presence of Jupiter, the Sun moves in a small orbit of radius \(742,000 \mathrm{~km}\) with a period of \(11.86\) years. (a) Calculate the Sun's orbital speed in meters per second. (b) An astronomer on a hypothetical planet orbiting the star Vega, 25 light- years from the Sun, wants to use the astrometric method to search for planets orbiting the Sun. What would be the angular diameter of the Sun's orbit as seen by this alien astronomer? Would the Sun's motion be discernible if the alien astronomer could measure positions to an accuracy of \(0.001\) arcsec? (c) Repeat part (b), but now let the astronomer be located on a hypothetical planet in the Pleiades star cluster, 360 light-years from the Sun. Would the Sun's motion be discernible to this astronomer?

Use the Stamy Night Enthusiast \({ }^{\mathrm{TM}}\) program to examine stars that have planets. Select Stars > ExtraSolar Planets in the Favourites menu. In the star map that appears, each circled star has one or more planets. (You can zoom in and zoom out using the buttons at the right side of the toolbar. Click the Info tab at the left of the main window to open the Info pane and open the Other Data panel. Then click on a circled star to learn more about its properties. Note that the information given for each star includes the apparent magnitude, which is a measure of how bright each star appears as seen from Earth. Apparent magnitude uses a "backwards" scale: The greater the value of the apparent magnitude, the dimmer the star. Most of the brighter stars you can see with the naked eye from the Earth have apparent magnitudes between 0 and 1 , while the dimmest star you can see from a dark location has apparent magnitude 6. Are most of the circled stars visible to the naked eye? List at least two stars that are visible, and include their apparent magnitudes.

What is the nebular hypothesis? Why is this hypothesis accepted?
See all solutions

Recommended explanations on Physics Textbooks

Fundamentals of Physics

Read Explanation

Famous Physicists

Read Explanation

Electricity

Read Explanation

Classical Mechanics

Read Explanation

Turning Points in Physics

Read Explanation

Physical Quantities And Units

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