Right ascention to my knowledge is measured by how far something is across the celestial equator (basically an imaginary line extending from outside the equator), so it is longitude but for space (the across angle). There would be one set point for right ascention somewhere on the earth, not specified i don't think, which would be set as 0 degrees or hours and then you'd go across the celestial equator until you got to the point of the object you're looking for.
Don't know if that makes sense but hope it helps!
Also, topics on the 2015 paper (we did it in class a couple months back):
- Q1. Telescopes, reliability of results, alien life and neutron star formation.
- Q2. Good places for telescopes and 6 marker on good/bad of isolated mountain telescopes.
- Q3. Relationships of data, nothing really on spec.
- Q4. 6 marker on 'ladder of distances' (parallax, cepheid and hubble's law) and how hubble law depends on other methods.
- Q5. Hertzsprung-Russell diagram, line spectra, energy transfers in stars and Kelvin to Celsius calculation.
- Q6. 6 marker on how relationships of pressure, temperature and volume of gas explain how hydrogen fusion begins in a star.