How does the interstellar gas change the light of stars passing through it, even if no dust is also present?
What will be an ideal response?
Even the cool, thin atoms of gas will absorb some wavelengths of light, and these absorption lines will be very sharp, compared to the lines from the denser star's photosphere. So we can find the composition of the cool gases with these lines, and from their Doppler shifts, the motions of the gas clouds as well.
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A plot of the continuous spectra of five different stars is shown in Figure 6-1. Based on these spectra, which of the stars has the lowest temperature?
Between the processes of nuclear fission and fusion, radioactive by-products are more characteristic of nuclear
A) fission. B) fusion. C) both of these D) neither of these
Which of the following procedures would not be expected to increase the yield strength of LDPE?
(a) Quenching the LDPE to room temperature from the liquid state (b) Increasing the crystallinity (c) Increasing the molecular mass (d) Decreasing the side branching
What happens to the kinetic energy of a speedy proton when its relativistic mass doubles?
A) It doubles. B) It more than doubles. C) It less than doubles. D) It must increase, but it is impossible to say by how much.