Spherical and Spatial Distribution of WZ Sagittae Type Dwarf Novae

Nearly 100 WZ Sagittae-type dwarf novae are listed by the end of August 2015 in the AAVSO database.This type of variable stars are distributed much more isotropically than the Galactic novae.Moreover very few of them are in the direction to the Galactic center.The distance of each WZ Sge-type star can be estimated by assuming that the luminosity at maximum light is the same.Then we can depict the spatial distribution of the WZ Sge-type stars The requirement that all of these WZ Sge-type star are confined within the galactic thin disc gives a constraint on the extinction of the optical light due to the interstellar matter in the galactic thin disc.