H-R Diagram Discipline: Education Having the information about spectral types was useful, but astronomers wanted to look for trends in the data. In 1911 Ejnar Hertzsprung plotted the absolute magnitude of stars against their colors. Two years later Henry Norris Russell independently did a similar graph using spectral types.Tags: starsluminositytemperatureHertzsprungRussellwhite dwarfblue giantsred giantssupergiants
Types of Stars Discipline: Education Astronomers have always been fascinated by the different sizes and colors of stars that they observed. In 1817 an German instrument maker named Joseph von Fraunhofer attached a spectroscope to a telescope and pointed it at the stars. He found that different stars have different absorption lines in their spectra. At first astronomers did not understand why different stars would have different absoprtion lines.Tags: starsspectraspectral classtemperatureHenry DraperAnnie Jump CannonAntonia MauryEdward Pickering
