Why are interstellar absorption lines so narrow compared to the width of lines which originate in the photospheres of stars?
What will be an ideal response?
Much of the interstellar gas is cold, and its density is very low. Because atoms in the ISM move slowly and collide only rarely, interstellar absorption lines are extremely narrow.
You might also like to view...
Falsifying a theory: The steady state universe was an alternate hypothesis to the Big Bang. Summarize this hypothesis, and explain the two observations which disproved it
What will be an ideal response?
What must be the diameter of a cylindrical 120-m long metal wire if its resistance is to be 6.0 ?? The resistivity of this metal is 1.68 × 10-8 ? ? m
A) 0.65 cm B) 0.65 mm C) 0.0325 mm D) 0.065 mm E) 0.325 mm
One type of binary star is _______________ binary
Fill in the blank(s) with correct word
A star less massive than the Sun will have
A) an identical lifetime as the Sun because although its overall mass is lower, the mass of its nuclear burning core is the same B) a shorter lifetime because it has less fuel to burn C) a longer lifetime because although its overall mass is lower, the mass of its nuclear burning core is larger D) a longer lifetime because its central core is cooler and less dense