The Hertzsprung–Russell diagram is a scatter graph of stars showing the relationship between the stars’ absolute magnitudes or luminosities versus their spectral types or classifications and effective temperatures. Hertzsprung-Russell diagrams are not pictures or maps of the locations of the stars. Rather, they plot each star on a graph measuring the star’s absolute magnitude or brightness against its temperature and color.
The ISS may be unoccupied for the first time in over a decade. After the Russian Progress vehicle (seen above) failed on its last flight aboard a Soyuz rocket, the Russians are trying to figure out the problem before its next scheduled resupply mission. If they don’t figure it out in time, the next batch of astronauts and cosmonauts may not go up before the current 5 come down.