Which of the following quasars would you expect to have the largest number of hydrogen absorption lines in its spectrum? 

Why can't we see the structures in the centre of our Galaxy with optical telescopes? 

What is the shape of the Milky Way’s halo? 

What shape will the galaxy resulting from the impending collision between Andromeda and Milky Way most likely have? 

Which kind of object is the best standard candle for measuring distances to extremely distant galaxies? 

How might two colliding spiral galaxies tend to create an elliptical galaxy? 

What products are formed as an immediate result of the fusion of two protons in p-p chain reaction? 

The fact that we observe neutrinos from the Sun provides direct evidence of 

At the centre of the Sun, fusion converts hydrogen into 

What causes the cycle of solar activity?