Helium is very common in the Sun and calcium is rare. Why arehelium lines weak and calcium lines strong in the visible spectrumof the Sun?
How would a star regain its state of equilibrium if the energygeneration rate of a star were to become slightly smaller than itsequilibrium?
Why do metal poor stars have the most elliptical orbits? Fromwhere do they obtain their metals?
why do so few visual binary star systems been fully analyzedto reveal individual masses?
When we look at light curve for an eclipsing binary systemwith total eclipses, how can we tell which star is hotter?
Why do extremely cool stars look fainter than we might expectfrom their luminosities and distances?
Why can't we use solar type stars as spiral tracers? what typeof stars make good spiral tracers? why? What characteristics dothey have to perform this function?
in some old, dense stars, a few blue stars, known as bluestragglers are seen. why are blue stars unexpected in suchclusters? If stars that stick together mix their materialthoroughly when they collide, how might you explain such bluestars?
Supposed you jumped into a black hole feet first? what wouldhappen to you? what would your friends who stayed behind actuallysee?
Why are there different types of galaxies?
what is the eventual fate of the milky way galaxy? whatprocess will lead to this fate? can anything change this?
What are the processes that are responsible for the formationof an elliptical galaxy in comparison to a spiral galaxy? Whycannot galaxies evolve from elliptical to spiral and from spiral toelliptical?
Is it surprising that a pulsar is not seen in every supernovaremnant? why?
How do we form the conclusion that quasars are so vary faraway?
How many times longer does a .50 - M star fuse hydrogen atit's core than does a 1.5 - M star?
How many 0.75 - M main sequence stars would it take to equalthe luminosity of one 15 - M star?
