103. Brightness of stars. Astronomers use the magnitude scale to measure apparent brightness. The relative intensity is calculated by dividing the intensity of light from the star Vega by that of the star of interest. The apparent magnitude is then given by

• 103. Brightness of stars. Astronomers use the magnitude scale to measure apparent brightness. The relative intensity is calculated by dividing the intensity of light from the star Vega by that of the star of interest. The apparent magnitude is then given by

• The light striking Earth from Vega is 2.9 times as intense as that from the star Fomalhaut. What is the apparent magnitude of Fomalhaut?

• The star Antares has an apparent magnitude of 0.92. How does the intensity of light reaching Earth from Antares compare with that from Vega?

• If the intensity of light striking Earth from one star is twice that of another, how do their apparent magnitudes compare?

• Can a star have negative apparent magnitude? If so, would it be a very bright or a very dim star?