Powerful Plots Of The Hertzsprung-Russell Diagram

One of the most useful and powerful plots in astrophysics is the Hertzsprung-Russell diagram. It originated in 1911 when the Danish astronomer, Ejnar Hertzsprung, plotted the absolute magnitude of stars against their colour (hence effective temperature). In 1913 the independent American astronomer Henry Norris Russell used spectral class against absolute magnitude. Their resultant plots showed that the relationship between temperature and luminosity of a star was not random but instead appeared to fall into distinct groups. These are seen in the H-R diagram below. It has a few specific stars included in the plot but otherwise just shows the main regions. They used a model of the relations in humans and is calculated and found as random distributions.

The HR diagram has a similar trend to the height vs mass graph but upside down. The majority of stars, including our Sun, are found along a region called the Main Sequence. Main Sequence stars vary widely in effective temperature but the hotter they are, the more luminous they are. The main sequence tends to follow a band or a line going from the bottom right of the diagram to the top left. These stars are fusing hydrogen to helium in their cores. Stars spend the bulk of their existence as main sequence stars. Other major groups of stars found on the H-R diagram are the giants and supergiants; luminous stars that have evolved off the main sequence, and the white dwarfs. But how can you measure the temperature or the mass of a sun if you’re not there? We would have to start finding information, then create theorems to calculate something without actually measuring it by hand.In 1911, Rutherford created a model of an atom where the electrons will spin around the nucleus until the atom eventually dies. In 1913, Niels Bohr improved on this model and stated that there are shells in an atom. The electron jumps to a shell above then comes back down emitting energy which is also