Stars

Which object in our solar system is a star?

• Venus

• Jupiter

• the Sun

• the Moon

Light and other forms of electromagnetic radiation are given off by stars using energy released during

• nuclear fusion

• conduction

• convection

• radioactive decay

Where would a new star most likely form?

• in a nebula

• in a supernova

• in a black hole

• in an asteroid field

The diagram shows an inferred sequence in which our solar system formed from a giant interstellar cloud of gas and debris. Stage A shows the collapse of the gas cloud, stage B shows its flattening, and stage C shows the sequence that led to the formation of planets. From stage B to stage C, the young Sun was created

• when gravity caused the center of the cloud to contract

• when gravity caused heavy dust particles to split apart

• by outgassing from the spinning interstellar cloud

• by outgassing from Earth’s interior

The diagram represents possible stages in the life cycle of stars. What factor below usually determines whether a star will be on the main sequence?

• age

• mass

• temperature

• distance

The final stage of a star’s existence is determined by its mass. The most massive stars will end their lives as

• supergiant stars

• red giants

• white dwarf stars

• black holes

At which phase of its evolutionary life is a white dwarf star?

• the late phase for a small mass star

• the remains of a larger star’s explosion

• in the main sequence phase

• early phases, soon after a star’s formation

A probable fate of our sun is

• to expand as a red giant, undergo a nova outburst and end as a white dwarf

• to shrink to a white dwarf then eventually expand to a red giant

• become hotter and expand to a blue supergiant

• to become a black hole

The explosion of a massive star near the end of its life is known as

• nova

• supernova

• pulsar

• nebula

According to the diagram, the life-cycle path followed by a star is determined by the star’s initial

• mass and size

• luminosity and color

• temperature and origin

• luminosity and structure