Table 1 shows some data for the star HD 21389:
The apparent magnitude of HD 21389 is 4.654.654.65.
State the spectral class of HD 21389.
Calculate, in pc\text{pc}pc, the distance from HD 21389 to the Earth.
18 exam-style questions on AQA A Level Physics Classification of stars (A-level only), covering Classification by luminosity (A-level only), Absolute magnitude, *M* (A-level only), Classification by temperature, black-body radiation (A-level only), Principles of the use of stellar spectral classes (A-level only), The Hertzsprung–Russell (HR) diagram (A-level only), and Supernovae, neutron stars and black holes (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.