Here we attempt to infer the recent history of star formation in the BCD galaxy VII Zw403 , based on an analysis that accounts for the dynamics of the remnant generated either by an instantaneous burst or by a continuous star formation event .
The models are restricted by the size of the diffuse X-ray emitting region , the H _ { \alpha } luminosity from the star-forming region and the superbubble diffuse X-ray luminosity .

We have re-observed VII Zw403 with a better sensitivity corresponding to the threshold H _ { \alpha } flux 8.15 \times 10 ^ { -17 } erg cm ^ { -2 } s ^ { -1 } .
The total H _ { \alpha } luminosity derived from our data is much larger than reported before , and presents a variety of ionized filaments and incomplete shells superimposed on the diffuse H _ { \alpha } emission .
This result has a profound impact on the predicted properties of the starburst blown superbubble .
Numerical calculations based on the HST H _ { \alpha } data , predict two different scenarios of star formation able to match simultaneously all observed parameters .
These are an instantaneous burst of star formation with a total mass of 5 \times 10 ^ { 5 } M _ { \odot } and a star-forming event with a constant SFR = 4 \times 10 ^ { -3 } M _ { \odot } yr ^ { -1 } , which lasts for 35 Myrs .
The numerical calculations based on the energy input rate derived from our observations predict a short episode of star formation lasting less than 10 Myrs with a total star cluster mass \sim ( 1 - 3 ) \times 10 ^ { 6 } M _ { \odot } .
However , the five main star-forming knots are sufficiently distant to form a coherent shell in a short time scale , and still keep their energies blocked within local , spatially separated bubbles .
The X-ray luminosities of these is here shown to be consistent with the ROSAT PSPC diffuse X-ray emission .