Ismail Bouillaud (Bullialdus; September 28, 1605 - November 25, 1694)
Ismail Bouillaud (or Boulliau, or latinized Bullialdus) was a French
librarian, astronomer and priest, who was born in 1605 in Loudun where he
studied, then traveling in Italy, Holland and Germany for buying books.
He published Astronomia philolaica in 1645, supporting Kepler's
elliptical orbits, and assuming an inverse-square force law for the first
He observed the Andromeda "Nebula" (M31)
in 1661, but according to Allen (1899/1963), he
expressedly mentioned that this
"Nebula" had been observed 150 years earlier by some anonymous but expert
Nevertheless, Edmond Halley accounted the discovery
of this object to him in his 1716 treat of Nebulae.
Because the "nebula" had not been documented by so many famous astronomers,
Boulliau suspected that it might been variable, similar to
Mira Ceti which
he also studied, and attempted to calculate a period of variation - of 333 days,
compared to the modern value of 332.
He died in 1694 in Paris.
The astronomical community has named a Moon crater to his honor: Bullialdus
(20.7S, 22.2W, 60 km diameter, in 1935).
- Allen, Richard Hinckley,
1899. Star-Names and their Meaning. G.E. Stechert. Republished
corrected in 1963 as Star Names, Their Lore and Meaning, Dover, New York.
Here: p. 39.
- Halley, Edmond,
1716. An Account of several Nebulae or lucid Spots like Clouds,
lately discovered among the Fixt Stars by help of the Telescope.
Phil. Trans., Vol. 29 (1714-1716), Num. 347 (Jan-Mar 1716), p. 390-392.
- Kenneth Glyn Jones, 1968.
The Search for the Nebulae -- II.
Journal of the British Astronomical Association, Vol. 78, No. 5 (1968),
p. 360-368. Section on Bouillaud: p. 364-366.
Reprinted in: The Search for the Nebulae. Chalfont St. Giles, 1975.
[History Home] |