A star identical to the Sun is 1500 parsecs away. a) What is the flux received...

  

Transcribed Image Text:

A star identical to the Sun is 1500 parsecs away. a) What is the flux received at Earth (ignore the effects of the atmosphere, telescope losses and CCD quantum efficiency) in W/m²? b) How many photons would be received per second by a telescope with a 1 meter diameter (again ignore all losses and assume an average wavelength of 500 nm)? How long an exposure would be needed to achieve a signal-to-noise ratio of 1000? 3. [13 marks] Use the Sun's radius and luminosity (given in the constants section) to calculate a) its temperature using the blackbody radiation law b) If the Sun's luminosity were all emitted as photons of wavelength 500 nm, how many photons would the Sun's produce every second? A star identical to the Sun is 1500 parsecs away. a) What is the flux received at Earth (ignore the effects of the atmosphere, telescope losses and CCD quantum efficiency) in W/m²? b) How many photons would be received per second by a telescope with a 1 meter diameter (again ignore all losses and assume an average wavelength of 500 nm)? How long an exposure would be needed to achieve a signal-to-noise ratio of 1000? 3. [13 marks] Use the Sun's radius and luminosity (given in the constants section) to calculate a) its temperature using the blackbody radiation law b) If the Sun's luminosity were all emitted as photons of wavelength 500 nm, how many photons would the Sun's produce every second?

Answer rating: 100% (QA)

Solution a To calculate the flux received at Earth from a star we can use the inverse square law for radiation The formula for flux F is F L 4 d Where ... View the full answer