ROSAT performed a 6-month all-sky survey in the interval July
30, 1990 to January 25, 1991, during which 96 percent of the sky
was covered. During the survey two filters were alternated daily
to provide two EUV passbands. These were S1 [60-140 A (90-206
eV)] and S2 [110-200 A (62-110 eV)]. Sky coverage was greatest
at the ecliptic poles, where integrated exposures reached 70,000
seconds in each filter; at the ecliptic equator exposures were
lowest, being around 1,500 seconds per filter. The sources
listed in this Bright Source Catalogue were initially detected
using a circular sliding box technique and a Poisson
significance test. A maximum likelihood technique was used to
determine source parameters. The criteria for inclusion of an
EUV source in this catalogue were: greater than 4.5 sigma
detection in one filter, and visual confirmation of the source.
Simulations suggests that less than one false detection can be
expected in the WFC Bright Source Catalogue. Catalog_Designation
WFC Bright Source Catalogue so