2024HSCQ5A star cluster is a group of stars that form at the same time. Hertzsprung–Russell diagrams for three star clusters, XXX, YYY and ZZZ are shown. Which row of the table correctly shows the three star clusters from youngest to oldest? A. Youngest YY, then , then oldest B. Youngest , then , then oldest C. Youngest , then , then oldest D. Youngest , then , then oldest
2024TrialQ10This is a Hertzsprung–Russell (H–R) diagram showing many star plots. The axes are not labelled. Which of the following statements is true of the luminosity and temperature of stars A and B? A. The luminosity of star A is lower while the temperature of star B is higher. B. The luminosity of star A is lower while the temperature of star B is lower. C. The luminosity of star A is higher while the temperature of star B is higher. D. The luminosity of star A is higher while the temperature of star B is lower.1 markMultiple choice
2024TrialQ16Two stars, A and B, are equally bright as seen from the Earth. Stars A and B are 101010 and 151515 parsecs away from Earth respectively. One parsec =3.26=3.26=3.26 light years. Which of the following statements about the luminosities of stars A and B (LAL_ALA and LBL_BLB) are correct? A. LA=32LBL_A=\frac{3}{2}L_BLA=23LB B. LA=23LBL_A=\frac{2}{3}L_BLA=32LB C. LA=49LBL_A=\frac{4}{9}L_BLA=94LB D. LA=94LBL_A=\frac{9}{4}L_BLA=49LB1 markMultiple choice
2024HSCQ22 (a)The following graph, based on the data gathered by Hubble, shows the relationship between the recessional velocity of galaxies and their distance from Earth. Describe the significance of the graph to our understanding of the universe.2 marksShort answer
2024HSCQ22 (b)The following graph, based on the data gathered by Hubble, shows the relationship between the recessional velocity of galaxies and their distance from Earth. How were the recessional velocities of galaxies determined?3 marksShort answer