April 25 – Gérard de Vaucouleurs

Born today in 1918, Gérard de Vaucouleurs was a French astronomer who specialized in galaxies.   He is best known these days for his modification of Edwin Hubble‘s galaxy classification scheme.  De Vaucouleurs added barsrings and spiral arms to Hubble’s basic system of ellipticalspiral and lenticular galaxies.

Barred Spiral Galaxy NGC 1300 (image credit: NASA/ESA).
Barred Spiral Galaxy NGC 1300 (image credit: STScI/NASA/ESA).

In honour of Monsieur de Vaucouleurs, Today’s photo (a composite image by the Hubble Space Telescope) shows the most barred, armed, spiral galaxy I could find.  NGC 1300 is in the constellation Eridanus. It was discovered by John Herschel in 1835, and is a member of the Eridanus Cluster of about 200 galaxies.


 1848  –  The large main belt asteroid 9 Metis was discovered by Irish astronomer Andrew Graham.  It was to be the last Irish asteroid for 106 years.


1890  –  Asteroid 291 Alice, of the Flora family, discovered by Johann Palisa. Alice is roughly the shape of a giant jelly bean, at about 19 x 12 x 11 km.


1890  –  Asteroid 292 Ludovica was also discovered today, and was also one of Johann Palisa’s. Palisa was obviously smoking on April 25th, whereas Auguste Charlois was probably steaming some time afterwards, as he too discovered both asteroids, but on the 26th.


1906  –  Asteroid 599 Luisa was discovered from Taunton, Mass., by prolific American asteroid and comet hunter Joel Hastings Metcalf. The origin of the name isn’t known, but I would like to point out that Metcalf’s father was called Lewis.


1993  –  Launch of X-ray telescope Alexis (Array of Low Energy X-Ray Imaging Sensors).