Stars and the Universe

The mass of the Sun is $2.0 \times 10^{30}\,\text{kg}$. Which element makes up most of that mass?

Feb/March 2023

The star closest to the Sun is Proxima Centauri, which is 4.2 light years away. Which statements are correct?

Feb/March 2023

The Hubble constant $H_0$ is determined by two quantities: the speed $v$ at which a galaxy is moving away from the Earth and the distance $d$ of the galaxy from the Earth. What relation connects $v$ and $d$, and what is the present estimate of $H_0$?

Feb/March 2023

Calculate the average orbital speed of Mars in km/s.

Feb/March 2023

Which row gives the elements that occur most abundantly in the Sun and the parts of the electromagnetic spectrum where most of the Sun’s energy is emitted?

Feb/March 2024

What does the term light-year mean?

Feb/March 2024

Approximately what is the diameter of the Milky Way?

Feb/March 2024

State the condition that allows a protostar to develop into a stable star.

Feb/March 2024

A student draws a graph showing the speed of different galaxies moving away from the Earth plotted against their distance from the Earth. From the best straight line on the graph, what is the value of the Hubble constant $H_0$?

Feb/March 2025

By what main process is energy released in the Sun?

May/June 2018

The Sun is made up mainly of two elements. Which two elements are they?

May/June 2023

Which of the following statements about the Milky Way is correct?

May/June 2023

An astronomer detects redshift in the light from a distant galaxy. Which statement about redshift is correct?

May/June 2023

Which statement correctly describes a galaxy?

May/June 2023

Which nuclear reaction provides the energy for a stable star?

May/June 2023

In what sequence do the stages in the life cycle of a star take place?

May/June 2023

What does the term Hubble constant mean?

May/June 2023

Which row states the power source of a stable star?

May/June 2023

Which quantity can be found from the brightness of a supernova in a distant galaxy?

May/June 2023

State the equation used to define the average orbital speed $v$ of a planet. State the meaning of any symbols you use.

May/June 2023

Show that the distance for $1$ light-year is $9.5 \times 10^{15}\,\text{m}$.

May/June 2023

What does the term light-year mean?

May/June 2024

What does the Universe consist of?

May/June 2024

Which gases make up most of the Sun?

May/June 2024

What is the Milky Way’s approximate diameter?

May/June 2024

Which main process provides the Sun’s power?

May/June 2024

The Earth is $3.0 \times 10^{20}\,\text{km}$ away from a galaxy. At what speed is the galaxy receding from the Earth?

May/June 2024

An astronomer studies a galaxy that is far away. The table indicates how the galaxy’s distance and its recession speed are found. Which row is correct?

May/June 2024

Which statement concerning the life cycle of a star is correct?

May/June 2024

A galaxy at a distance of $3.1 \times 10^{21}\,\text{km}$ is receding from the Earth at a speed of $7000\,\text{km s}^{-1}$. What Hubble constant $H_0$ is obtained from this information, and what is the speed of a galaxy that lies $6.2 \times 10^{21}\,\text{km}$ from the Earth?

May/June 2024

During the life cycle of a star, in what sequence are the objects listed formed?

May/June 2024

How far does light travel in one year?

May/June 2024

State the names of any two other categories of bodies present in the Solar System.

May/June 2024

A range of objects are found in the Solar System. A few of them are listed here.

May/June 2024

The Sun is among many billions of stars within the Milky Way. It gives out a very large amount of energy as electromagnetic radiation.

May/June 2024

Name the galaxy in which the Sun is located.

May/June 2024

A galaxy lies roughly $1.2 \times 10^{26}$ m from the Earth.

May/June 2024

Electromagnetic radiation emitted by distant galaxies appears redshifted when it is detected on Earth. This provides evidence for the Big Bang Theory. Which statement is correct?

May/June 2025

Which of the following statements about the Milky Way is correct?

May/June 2025

Which statement concerning the Universe is correct?

May/June 2025

Which of the following statements about the cosmic microwave background radiation (CMBR) is correct?

May/June 2025

A galaxy is receding from the Earth with a velocity of $3000\,\text{km s}^{-1}$. What is the distance between the Earth and this galaxy?

May/June 2025

A faraway galaxy is receding from the Milky Way at $4\,400\,000\ \text{m s}^{-1}$. How far away, approximately, is this galaxy from the Milky Way?

May/June 2025

The Solar System consists of the Sun together with eight planets.

May/June 2025

Fig. 10.1 presents a scatter graph of the speed at which galaxies move away from the Earth against their distance from the Earth. The vertical axis is labelled speed of galaxy $10^{4}\,\text{km\,s}^{-1}$. The horizontal axis is labelled distance of galaxy from Earth $10^{20}\,\text{km}$. A best-fit line has been drawn.

May/June 2025

Fig. 3.1 illustrates solar cells that convert radiation from the Sun into electrical energy.

Oct/Nov 2017

What is the origin of the Sun’s energy?

Oct/Nov 2020

Which of these statements about the Sun is correct?

Oct/Nov 2023

What gives evidence that the Universe is expanding?

Oct/Nov 2023

The closest star to the Sun is around four light-years from Earth. A student gives three claims about the star. Which of these claims are correct?

Oct/Nov 2023

Which of the following statements about the Sun is correct?

Oct/Nov 2023

The table shows some details about several stars. Which star will later explode as a supernova?

Oct/Nov 2023

By what process does the Sun generate its energy?

Oct/Nov 2023

The nearest star to the Sun is roughly four light-years from Earth. A student makes three claims about the star. 1 Light from the star needs about four years to reach Earth. 2 Light from the Sun takes around four years to go to the star and then return to Earth. 3 The star lies beyond our galaxy. Which claims are correct?

Oct/Nov 2023

Fig. 11.1 shows the Sun together with part of the Solar System. In the diagram, the Sun is at the centre, Mercury and Mars are already labelled on the orbits, and three dotted label lines are shown.

Oct/Nov 2023

The Milky Way is just one among many billions of galaxies. Every galaxy contains many billions of stable stars.

Oct/Nov 2023

Complete the sentence: Protostars are produced from [BLANK].

Oct/Nov 2023

In space physics, what quantity does the symbol $H_0$ denote?

Oct/Nov 2023

Which row gives the correct description of the Sun and the Milky Way?

Oct/Nov 2024

What is the Milky Way’s approximate diameter?

Oct/Nov 2024

Which statement about the Sun is incorrect?

Oct/Nov 2024

Which statement regarding the Milky Way galaxy is correct?

Oct/Nov 2024

The Milky Way is a ......1...... containing roughly one hundred ......2...... stars. Which words correctly fill gaps 1 and 2?

Oct/Nov 2024

Which of the following statements concerning the Sun is correct?

Oct/Nov 2024

An astronomer measures a galaxy’s distance from the Earth as $2.5 \times 10^{21}\ \text{km}$ in order to determine the value of the Hubble constant. She also finds that the galaxy is receding from the Earth at a speed of $5.2 \times 10^{3}\ \text{km s}^{-1}$. Using these data, what is the value of the Hubble constant?

Oct/Nov 2024

What occurs when a protostar develops into a stable star?

Oct/Nov 2024

Which quantity gives an estimate of the age of the Universe?

Oct/Nov 2024

The Milky Way’s diameter is about 100 000 light years. Express this distance in metres.

Oct/Nov 2024

State the name of the force that holds the Moon in orbit round the Earth.

Oct/Nov 2024

The Milky Way is the galaxy that contains the Solar System.

Oct/Nov 2024

Describe the process by which a black hole is formed from a star of greater mass.

Oct/Nov 2024

From Fig. 9.1, identify every length that represents one wavelength.

Oct/Nov 2024

Which of the following statements about the Sun is correct?

Oct/Nov 2025

What is the name of the galaxy in which the Sun is found?

Oct/Nov 2025

Light arriving from distant galaxies is seen to have a greater wavelength than the light that was emitted initially. This is known as redshift. What conclusion do astronomers draw about distant galaxies from this observation?

Oct/Nov 2025

A galaxy lies 60 million light-years from the Earth. It is receding at a speed of $1300\,\text{km s}^{-1}$. One light-year is approximately $9.5 \times 10^{12}\,\text{km}$. In one year, there are around $3.2 \times 10^{7}$ seconds. Which expression may be used to estimate the age of the Universe in years?

Oct/Nov 2025

Earth lies $6.6 \times 10^{20}\,\text{m}$ away from the galaxy Draco II. What is this distance in light-years?

Oct/Nov 2025

What could be one outcome of a supernova explosion?

Oct/Nov 2025

Star X has a greater diameter than star Y, yet both stars emit radiation at the same power. Which statement is correct?

Oct/Nov 2025

The table shows information about four different stars. Which one of the stars is the Sun?

Oct/Nov 2025

What can be produced immediately after a supernova?

Oct/Nov 2025

Planets were formed from interstellar clouds made up of gas and [BLANK].

Oct/Nov 2025

Fig. 10.1 illustrates the Earth’s orbit and the path of a comet as it moves around the Sun. Orbit A is the smaller, almost circular path around the Sun. Orbit B is the much larger, stretched-out path around the Sun.

Oct/Nov 2025