Death of large starsChapter 21&22

Supernova Ia

Death of high mass stars:

Neutron stars

Pulsars

Black holes

Fate of the large starsEnd mass

Less than 1.4 M sun White dwarf

Chandrasekhar limit

1.4 – 3 M sun Neutron star : First discovered by Jocelyn Bell as a pulsar in 1960s

Oppenheimer – Volkov limit

Greater than 3 M sun Black hole

Review fate of the starsanswer these question to review the fate of the smaller stars from last lecture!

1. Where did the elements heavier than Fe from? a) It formed during the big bang, b) it formed in the large stars through fusion process. C) during SN explosion

2. If a WD in binary system gain mass from its companion, it may result in: a) SN type Ia, b) SN type II, c) CVS type 1, d) CVS type 2

3. Chandrasekhar limit marks the mass limit between: a) brown dwarf and red dwarf, b) red dwarf and stars that eventually becomes red giant, c) white dwarf and neutron star, d) neutron star and black hole

4. T/F the material that forms stars are often left over material from the previous stars in that region.

5. Which type of supernova is generally brighter? A) type Ia, b) Ib, c) Ic, d) II, e) all are about the same

Click on “enter” to review your answers: 1. c, 2. a, 3. c, 4. T 5. a

21-1 Why astronomers predicted the existence of neutron stars before they were discovered

21-2 What pulsars are and how they were discovered

21-3 The relationship between pulsars and neutron stars

21-4 Why pulsars slow down over time

21-5 What exotic states of matter are thought to exist inside neutron stars

21-6 How neutron stars with abnormally strong magnetic fields can produce amazingly intense bursts of radiation

21-7 How some pulsars are accelerated to truly dizzying rotation speeds

Chapter 21By reading this chapter, you will learn

21-8 How pulsars in close binary systems can emit X-rays

21-9 How novae produced by white dwarfs are similar to X-ray bursters produced by neutron stars

21-10 What sets the upper limit on the mass of a neutron star

Crab Nebula and PulsarT= 0.033 seconds.

Recording a Pulsar

Rotating, Magnetized

Neutron Star

Structure of neutron stars quake?

X-ray bursters

Neutron stars1. Is neutron star a star? Explain

2. What is the difference between magnetar and neutron star?

3. Are all neutron stars pulsar? Are all pulsars neutron stars?

4. Explain the mechanism of pulsar:

5. Density of neutron star is about:

6. Size of typical neutron star is about:

7. What is neutron star quake?