In the years between 1905 and 1911, the astronomer Ejnar Hertzsprung and Henry Russell Norris developed a way of representing the accumulating astronomical and astrophysical data on stars that revealed the presence of a relationship between a stars brightness and its temperature.  This Hertzsprung-Russell or H-R Diagram would come to revolutionize our understanding of stellar evolution.

This week, with the help of steampunk attired lady and gentleman bugs, we take a look at the Doppler effect.  We use water waves, sound and light to examine the consequences of what happens with the observer of a wave is moving with respect to the wave's source.  We also look at the history of the idea from the work of Christian Doppler to the applications suggested by Ernst Mach.

This week we look at the spectral classification work of Antonia Maury and Annie Jump Cannon at the Harvard College Observatory.

In this week's episode we look at the early work of the Harvard College Observatory under the direction of Edward Charles Pickering.  We discuss his three big research initiatives: the visual photometric survey of stars, the All-Sky Survey and Catalogue and the Draper Memorial Catalogue that catalogued and classified the spectra of over 10,000 individual stars.  Instrumental in this last effort was Williamina Fleming: Pickering's one time housekeeper turned lead calculator in the project.

When Kirchhoff and Bunsen unlocked elemental spectra, they opened a new avenue of astrophysical investigation.  This work work was originally done by the quartet of Lewis Rutherfurd, Astronomer Royal George Airy, Father Angelo Secchi and William Huggins.  This work would lead to advances by Hermann Carl Vogel and Norman Lockyer who would be among those to propose an early model of stellar evolution.

In 1861, Gustav Kirchhoff published the astonishing results that he could, merely by examining the light received from the Sun, determine what elements it was made from.  One this episode, we'll trace the scientific investigation of the nature of light from Isaac Newton through Joseph Fraunhofer to the work of Kirchhoff and Robert Bunsen.

In this episode we look at the various methods to determine the distances to the stars including Christiaan Huygens' comparison method, Robert Hooke's zenith telescope and Wilhelm Struve's and Freidrich Bessel's telescopic measurements.  We also review the various ideas as to the distributions of these stars as advanced by Isaac Newton, William Stuckley, Thomas Wright and William Herschel.

In this episode we examine the fates of Phaeton, Vulcan and Pluto as they were thought of by Olbers, Le Verrier and Clyde Tombaugh.  We also examine the observations of James Craig Watson, introduce William Henry Pickering and follow the work of Percival Lowell.

In 1782, William Herschel entered the service of his Royal Majesty, King George III of the United Kingdom.  Over the next 20 years, he, along with his brother Alexander, would build hundred of telescopes including the largest research instruments in Europe as well as create the largest catalogue of deep sky objects ever compiled.  Assisting him in this was his sister, Caroline Herschel, who would become an exceptional astronomer in her own right. He would seek to answer questions about the Sun's motion through space, the behavior of variable stars, the nature of stellar spectra, the shape of the Milky Way galaxy and the Sun's position in it and the composition of nebulae. In 1788, he married Mary Pitt (nee Baldwin) and, in 1792, fathered a son, John Herschel, who would go on to be the preeminent scientist of the mid-18th century; competing his father's catalogue work by extending his observations to the Southern Hemisphere and doing much to create the technology of photography as well as making significant contributions to the philosophy of science.   John and his wife, Margaret, would have 12 children, three of whom would become scientists that would make significant contributions during their lifetimes.

William Herschel was a Hanoverian musician turned British astronomer.  In this episode we look at his journey from military band oboist to the court astronomer of King George III.  Along the way we look at his work as a composer and orchestral director, his entry into the field of astronomical instrument construction and his bringing of the techniques of natural history to astronomical investigation. We also discuss telescope design, what's the best telescope for a beginner to invest in and the idea of scientific serendipity.