Evolution of Stars

Q.

Which of the following is not a binary system?

Q. What is a planetary nebula

1. a disk of gas surrounding a protostar that may form into planets
2. what is left of the planets around a star after a low-mass star has ended its life
3. the expanding shell of gas that is no longer gravitationally held to the remnant of a low-mass star
4. the molecular cloud from which protostars form

Q. The large bright stars with a cool surface of ${2000}^{o}C$ to ${3000}^{o}C$, formed during the later stages of the evolution of a star like the sun as it runs out of $H_2$ fuel at its center are ___________.

1. red dwarf
2. white dwarf
3. red giants
4. brown dwarf

Q. During the transformation of a massive star ultimately into a black hole, which of the following sequence is correct?

1. Red giant stage $\to$ Supernova stage $\to$ White dwarf stage
2. White dwarf stage $\to$ Red giant stage $\to$ Supernova stage
3. White dwarf stage $\to$ Supernova stage $\to$ Red giant stage
4. Red giant stage $\to$ White dwarf stage $\to$ Supernova stage

Q. Compared to the star it evolved from, a red giant is

1. hotter and brighter.
2. cooler and brighter.
3. hotter and dimmer.
4. cooler and dimmer.

Q. What is a carbon star?

1. a red giant star whose atmosphere becomes carbon-rich through convection from the core
2. a star that fuses carbon in its core
3. another name for a white dwarf, a remnant of a star made mainly of carbon
4. a star that is made at least 50 percent of carbon

Q. Compared to the star it evolved from, a white dwarf is

1. hotter and brighter.
2. hotter and dimmer.
3. cooler and brighter.
4. cooler and dimmer.

Q.

How many helium nuclei fuse together when making carbon?

1. 2
2. 4
3. 3
4. None of the above