On planet Mysterio, when the sun is directly overhead the optical depth equals one (τ=1) at an altitude of 6 km. The neutral gas density at this altitude is 7×1011 particles/cm3. The ionization cross-section and photon flux at the top of the atmosphere have average values of σi = 3×10-19 cm2 and Itop = 5×109 photons cm-2 s-1, respectively. Calculate the photo-ionization rate at an altitude of 6 km for these conditions. Report answer in scientific notation to 2 significant digits. The photo-ionization rate is _____. cm-3 s-1
Stellar evolution
We may see thousands of stars in the dark sky. Our universe consists of billions of stars. Stars may appear tiny to us but they are huge balls of gasses. Sun is a star of average size. Some stars are even a thousand times larger than the sun. The stars do not exist forever they have a certain lifetime. The life span of the sun is about 10 billion years. The star undergoes various changes during its lifetime, this process is called stellar evolution. The structure of the sun-like star is shown below.
Red Shift
It is an astronomical phenomenon. In this phenomenon, increase in wavelength with corresponding decrease in photon energy and frequency of radiation of light. It is the displacement of spectrum of any kind of astronomical object to the longer wavelengths (red) side.
On planet Mysterio, when the sun is directly overhead the optical depth equals one (τ=1) at an altitude of 6 km. The neutral gas density at this altitude is 7×1011 particles/cm3. The ionization cross-section and photon flux at the top of the atmosphere have average values of σi = 3×10-19 cm2 and Itop = 5×109 photons cm-2 s-1, respectively.
Calculate the photo-ionization rate at an altitude of 6 km for these conditions. Report answer in scientific notation to 2 significant digits.
The photo-ionization rate is _____. cm-3 s-1
Step by step
Solved in 3 steps with 1 images
