Many years ago I wrote a short poem while listening to the final and most otherworldly section of The Planets by Gustav Holst: Neptune, the Mystic.
Here it is:
Neptune, the Mystic from The Planets by Gustav Holst
Royal Philharmonic Orchestra, Vernon Handley
Ambrosian Chorus, John McCarthy
Alto ALC 1013
The endless poetry of space Sends shivers across my spine,
And there upon the threshold sounds The now distant drone of time.
Music fills the spacecraft Starlight fills the night,
And there upon the threshold think I wonder, was I right?
The Planets was written by Holst between 1914 and 1916, and the premiere performance was at The Queen’s Hall, London, on September 29, 1918. Adrian Boult conducted the orchestra in a private performance for about 250 invited guests. The Queen’s Hall was destroyed by an incendiary bomb during the London Blitz in 1941, seven years after Holst’s death in 1934.
Pluto was discovered by Clyde Tombaugh in 1930, and was considered to be the ninth planet until its controversial demotion by the IAU in 2006. A number of composers have added a Pluto movement to ThePlanets (“Pluto, the Renewer” by Colin Matthews, for example), and even an improvised performance (“Pluto, the Unpredictable”) by Leonard Bernstein and the New York Philharmonic. I remember enjoying “Pluto, the Unknown” by American composer Peter Hamlin performed by the Des Moines Symphony in 1992, but unfortunately no recording of this work exists.
Belgian astronomer Eugène Joseph Delporte (1882-1955) discovered 66 asteroids from 1925 to 1942, but he is best remembered for determining the official boundaries of the 88 constellations, work he completed in 1928 and published in 1930. The constellation boundaries have remained unchanged since then.
The International Astronomical Union (IAU), founded, incidentally, in Brussels, Belgium in 1919, established the number of constellations at 88—the same number, coincidentally, as the keys on a piano—in 1922 under the guidance of American astronomer Henry Norris Russell (1877-1957). The IAU officially adopted Delporte’s constellation boundaries in 1928.
All the constellation boundaries lie along lines of constant right ascension and declination—as they existed in the year 1875. Why 1875 and not 1900, 1925, or 1930? American astronomer Benjamin Gould (1824-1896) had already drawn up southern constellation boundaries for epoch 1875, and Delporte built upon Gould’s earlier work.
As the direction of the Earth’s polar axis slowly changes due to precession, the constellation boundaries gradually tilt so that they no longer fall upon lines of constant right ascension and declination. Eventually, the tilt of the constellation boundaries will become large enough that the boundaries will probably be redefined to line up with the equatorial coordinate grid for some future epoch. When that happens, some borderline stars will move into an adjacent constellation. Even now, every year some stars change constellations because proper motion causes them to move across a constellation boundary. For faint stars, this happens frequently, but for bright stars such a constellation switch is exceedingly rare.