star classObservedMeasured or catalogued in the real sky, with its source cited.SimWhat the simulation generates or renders; it may depart from reality and says where.
Stellar classification
How astronomers sort stars by their spectra. A letter (O, B, A, F, G, K, M, and L, T, Y for the coolest objects) and a number give the surface temperature; a Roman numeral gives the size and brightness. The Sun is a G2V star.