Exam 17: Evolution of High-Mass Stars

The Type II supernova that created the Crab Nebula was seen by Chinese and Arab astronomers in the year 1054 CE..Assuming that the nebula is about 6,500 light-years from us, we know the star must have exploded approximately in the year

Essentially all the elements heavier than iron in our Milky Way were formed

Explain why a blue star cluster is probably younger than a red star cluster.

What is one way in which high-mass stars differ from low-mass stars?

When the core of a massive star collapses, a neutron star forms because

You observe a binary star system that consists of two nearly identical main-sequence stars, but you cannot resolve the binary (so it looks like a single star).Where would this "star" fall on the H-R diagram relative to the position of only a single star? If a star cluster consisted entirely of near-identical binary star systems such as these, what effect would this have on estimating the cluster's age?

A ⁴He atom has a binding energy of around 6.8 * 10¹⁴ joules (J) per kilogram (kg).If a single ⁴He atom has a mass of 6.6 *10 ^{- 27} kg, what is the binding energy of a single ⁴He atom?

How do Classical Cepheid variable stars differ from RR Lyrae variable stars in their masses, luminosities, and periods?

Although a Type II supernova shines with a luminosity of one billion Suns (10⁹ L_) in light, most of the energy in the explosion is emitted in another way.What is it, and how much more energy does it carry compared with that of the light?

In the figure shown below, the H-R diagram for the very old cluster M55 shows the presence of an intriguing type of object, namely main-sequence stars bluer and more luminous than the turnoff stars.These stars have been called "blue stragglers," and an attractive explanation might be that they are

What mechanism drives the pulsations in Cepheid variables?

What is the characteristic observational signal produced by a pulsar?

Which of the following arguments would render the discovery of a 100 M_SUN star with less than 0.5 percent massive elements most intriguing?

If you measure the average brightness and pulsation period of a classical Cepheid variable star, you can also determine its

Astronomers know they've found evidence of a past Type II supernova when they find

Massive stars synthesize chemical elements going from helium up to iron

The stellar energy is carried away primarily in the form of neutrinos when

Why do very massive stars collapse, causing them to explode, once they generate an iron core (hint: see figure below)?

In young clusters the light is dominated by

In the post-main-sequence stages, high-mass stars follow quasi-horizontal paths in the H-R diagram.This means that