Question 1: Define a supernova and describe the main types that occur in the universe.

Answer: A supernova is a powerful and luminous stellar explosion marking the end of a star's life cycle; main types include Type I and Type II supernovae, distinguished by their spectral lines and progenitors.

Question 2: Explain the process by which a massive star undergoes a supernova explosion.

Answer: A massive star exhausts its nuclear fuel, causing its core to collapse under gravity, leading to a rebound and explosion that ejects outer layers at high velocity, resulting in a supernova.

Question 3: What is the significance of supernovae in the creation of heavy elements?

Answer: Supernovae produce and disperse heavy elements like iron, nickel, and sulphur into space, contributing to the cosmic material for planets and life.

Question 1: Calculate the total energy released by a supernova that emits 10^44 joules of energy. Use the formula: Energy (J).

Answer: 10^44 joules

Question 2: If a supernova is observed at a distance of 10 million light-years, how long does the light take to reach Earth? (1 light-year ≈ 9.461 x 10^15 metres, speed of light ≈ 3 x 10^8 m/s).

Answer: Approximately 10 million years, as light travels at speed c over a distance of 10 million light-years.

Question 1: Describe a basic experimental setup to simulate the explosion of a supernova using safe, accessible materials. Outline the variables involved and safety precautions.

Answer: A possible setup includes using a balloon to represent a star, which is inflated until it bursts to simulate a supernova explosion. Variables include balloon size (mass/stellar mass), inflation pressure (core pressure), and burst timing. Safety precautions involve wearing eye protection, handling sharp objects carefully, and conducting the experiment in a clear, open area.

Question 2: Identify two key variables that astronomers measure when observing supernovae and explain their importance.

Answer: Luminosity and redshift; luminosity helps determine the energy output, while redshift indicates the distance and speed at which the supernova is moving away from Earth.

Question 1: A supernova's observed brightness decreases over time. Explain what this pattern indicates about the supernova's evolution and the distance from Earth.

Answer: The decreasing brightness indicates the supernova's explosion is fading, and analyzing the rate of decline helps estimate its distance and energy output.

Question 2: Given that a supernova's peak luminosity is 10^9 times that of the Sun, calculate its approximate absolute magnitude.

Answer: Using the formula: Magnitude difference = -2.5 log10(luminosity ratio), magnitude ≈ -2.5 × log10(10^9) ≈ -2.5 × 9 ≈ -22.5.

Question 1: Explain how the study of supernovae contributes to our understanding of the universe's expansion.

Answer: Supernovae, especially Type Ia, serve as standard candles to measure cosmic distances, helping scientists determine the rate of universe expansion and supporting theories like dark energy.

Question 2: Discuss the role of supernova remnants in the formation of new stars and planetary systems.

Answer: Supernova remnants consist of enriched gas and dust, which can collapse under gravity to form new stars and planets. This process recycles cosmic material, enriching the interstellar medium with heavy elements necessary for planet formation.