The Vinalia Urbana was held on 23 April. It was predominantly a wine festivalhttp://astronomy.activeboard.com/t48838904/vinalia-urbana/
April 23 marks the anniversary of the founding of the People's Liberation Army Navy in 1950
The ZX Spectrum 8-bit personal home computer was released in the United Kingdom in 1982https://en.wikipedia.org/wiki/ZX_Spectrum
The Ranger 4 spacecraft was launched on the 23rd April 1962(Failed before lunar impact)http://www.jpl.nasa.gov/missions/ranger-4/Molniya 1-01, was successfully launched on April 23, 1965
Rev. Dr. Thomas Romney Robinson (23 April 1792 - 28 February 1882) was an astronomer and physicist.http://en.wikipedia.org/wiki/John_Thomas_Romney_RobinsonWilliam Pearson (1767 - 1847) was an English schoolmaster and astronomer. http://en.wikipedia.org/wiki/William_Pearson_(astronomer)Max Karl Ernst Ludwig Planck (April 23, 1858 - October 4, 1947) was a German physicist http://astronomy.activeboard.com/t48838857/max-planck-1858-1947/Saint George (ca. 275/281 - 23 April 303) was, according to tradition, a Roman soldier from Syria Palaestinahttp://astronomy.activeboard.com/t42461052/saint-george/William Shakespeare (baptised 26 April 1564; died 23 April 1616) was an English poet and playwrighthttp://astronomy.activeboard.com/t48838954/william-shakespeare-1564-1616/
NGC 3501 was discovered by French astronomer Edouard Stephan on the 23rd April 1881.http://astronomy.activeboard.com/t57366159/ngc-3501/NGC 4807 German-Danish astronomer Heinrich Louis d'Arrest on the 23rd April 1865.http://astronomy.activeboard.com/t57366152/ngc-4807/NGC 5133 was discovered by French astronomer Édouard Stephan on the 23rd April 1881.http://astronomy.activeboard.com/t57366148/ngc-5133/
GRB 090423 is a gamma-ray burst (GRB) detected by the Swift Gamma-Ray Burst Mission on April 23, 2009 at 07:55:19 UTC. http://astronomy.activeboard.com/t27373885/grb-090423/Asteroid (1225) Ariane (1930 HK) was discovered on April 23, 1930 by Van Gent, H. at Johannesburg (LS). http://en.wikipedia.org/wiki/1225_Ariane
The Pi Puppids meteor shower peaks on the 23rd Aprilhttp://astronomy.activeboard.com/t53445239/pi-puppids/
North Pacific Ocean asteroid impact 23 April 2001 (1-10 kilotons)http://www.johnstonsarchive.net/astro/impacts.html
MeteoritesThe Braunschweig (L6) meteorite fell in Niedersachsen, Germany, on the 23rd April, 2013.http://astronomy.activeboard.com/t32758927/braunschweig-meteor/