A court of civil and criminal jurisdiction at Westminster, abolished in the reign of Charles I. So called because the ceiling or roof was decorated with gilt stars. Its jurisdiction was to punish such offences as the law had made no provision for.
The chamber where the “starrs” or Jewish documents were kept was a separate room. The Star Chamber was the Camera Stellata, not Camera Starrata.
“It is well known that, before the banishment of the Jews by Edward
I., their contracts and obligations were denominated ... starra, or
stars. ... The room in the exchequer where the
chests ... were kept was ... the starr-chamber.” —
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Star Chamber from Infoplease: