Chapter 21: Problem 8

How are rotating neutron stars able to produce pulses of radiation as seen by an observer on Earth?

Short Answer

Expert verified

Rotating neutron stars produce pulses of radiation observable from Earth due to their intense magnetic fields and consistent rotation. These magnetic fields accelerate particles, which emit radiation in beams focused towards the magnetic poles of the star. From Earth, these beams are only visible when they sweep across our line of sight, appearing as 'blinking' pulses of radiation. The regular 'blinking' is due to the consistent rotation of the star, not because the beam itself is turning on and off.

Step by step solution

Understanding Neutron Stars

Neutron stars are the remnants of supernova explosions, and are incredibly dense. They hold about 1.4 times the mass of the Sun within a radius of approximately 10 kilometers (approximately 6 miles). These stellar objects rotate at very high speeds, even up to hundreds of times per second.

Generation of Magnetic Fields

Neutron stars have incredibly strong magnetic fields, billions of times stronger than Earth's. This is due to their high density and rapid rotation. The rotation of these charged particles creates a magnetic field that extends out into space.

Formation of Pulsar Beams

These magnetic fields accelerate particles, causing them to emit radiation in the form of beams along the magnetic poles. In essence, the neutron star functions like a gigantic cosmic lighthouse. But unlike a conventional lighthouse whose light beam illuminates all directions as it rotates, the radiation from a neutron star is focused into two narrow cones of light shooting out from its magnetic poles. Therefore, the radiation beam is not visible all the time, only when it sweeps across an observer's line of sight.

Observation from Earth

From Earth, when the beam sweeps in the direction of our planet, it appears as a pulse of radiation. Although this pulse is regular due to the consistent rotation of the neutron star, to us it seems to 'blink' on and off because we only see the beam when it points directly at us. Hence, the pulse is not actually turning on and off, it's just moving in and out of our line of sight. This is the cause of the regular pulse of radiation we detect from pulsars, which are simply neutron stars that we can observe in this way.

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!

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

How are rotating neutron stars able to produce pulses of radiation as seen by an observer on Earth?

Short Answer

Step by step solution

Understanding Neutron Stars

Generation of Magnetic Fields

Formation of Pulsar Beams

Observation from Earth

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Physics Textbooks

Particle Model of Matter

Famous Physicists

Magnetism

Quantum Physics

Further Mechanics and Thermal Physics

Engineering Physics

Study anywhere. Anytime. Across all devices.