Stellar Evolution and Planetary Nebulae

What is fluorescence, in the context of light emission?

The emission of light by a substance that has absorbed light or other electromagnetic radiation

Why are the Large and Small Magellanic Clouds useful for estimating the mass of PNe?

Because the distances to the LMC and SMC are known to greater accuracy than the distances to the Galactic PNe

What is the range of masses observed for PNe?

0.01M⊙ - 0.27M⊙

What is the primary composition of PNe, by mass?

Hydrogen with some helium and metals Signup and view all the answers

Why are PNe often oxygen poor?

Because many of the progenitor stars were formed further in the past and thus started with less oxygen Signup and view all the answers

What is the relationship between the nebular radius and mass?

The mass increases as the radius increases Signup and view all the answers

What elements are characterized by strong and broad absorption lines in PG 1159 stars?

Helium (He II) and ionized Carbon (C IV and C III) Signup and view all the answers

What is thought to be the origin of the weak emission lines in Weak Emission Line Stars?

Lower mass-loss rates and peculiar chemical compositions Signup and view all the answers

What is the typical duration of the PG 1159 phase in the evolution of CSs?

A short-lived 20 phase Signup and view all the answers

Which of the following is NOT a characteristic of PG 1159 stars?

Strong and broad emission lines of helium (He II) Signup and view all the answers

What is the name of the prototype star that PG 1159 stars are named after?

PG 1159–035 Signup and view all the answers

What is the typical peak mass of planetary nebula central stars?

0.6M⊙ Signup and view all the answers

Why is it challenging to determine the lower end of the mass range of planetary nebula central stars?

Because of the wide range of measurement errors in mass determination Signup and view all the answers

What is the approximate radius of a 0.6M⊙ central star?

1.50 × 10−2R⊙ Signup and view all the answers

What elements are the cores of planetary nebula progenitor stars primarily composed of?

Carbon and oxygen Signup and view all the answers

How can planetary nebula central stars be divided?

By their hydrogen abundance in their atmospheres Signup and view all the answers

What is the typical size of a planetary nebula central star?

The size of the Earth Signup and view all the answers

What is the second hypothesis about strong stellar winds?

They are caused by pulsation. Signup and view all the answers

What is one piece of evidence for the hypothesis that pulsating stars produce dust?

Dust is observed around pulsating stars. Signup and view all the answers

What role do pulsating stars play in the evolution of low and intermediate mass stars?

They evolve into white dwarfs. Signup and view all the answers

What characteristics vary significantly among planetary nebulae?

Surface brightness and excitation class. Signup and view all the answers

What detection method did early astronomers like Charles Messier and William Herschel use to identify planetary nebulae?

Visual examination of telescopic views Signup and view all the answers

Which discovery method played a crucial role in early detections of planetary nebulae?

Objective-prism spectroscopy Signup and view all the answers

What is one way astronomers estimate the mass of a compact star (CS) in a planetary nebula (PN)?

By comparing the observed properties of the CS to theoretical stellar evolution models Signup and view all the answers

Why is determining the luminosity of a CS in a PN difficult?

Because astronomers do not have accurate distances to most PNe Signup and view all the answers

What is the Zanstra method used for in relation to CS temperature?

To determine the effective temperature of the CS Signup and view all the answers

What range of masses do planetary nebulae (PNe) generally have?

0.55 M⊙ to 0.8 M⊙ Signup and view all the answers

What is significant about the lower mass range of PNe?

Stars with masses around 0.55 M⊙ are expected to evolve into PNe Signup and view all the answers

What is one disadvantage of using a distance-independent method to estimate CS masses?

It requires accurate distances to most PNe Signup and view all the answers