When a star explodes in a supernova event, it releases an enormous amount of energy, including a burst of intense light. This light, known as the supernova's initial flash or prompt emission, travels at the speed of light through space.
Whether or not the light from an exploding star reaches us before it gets absorbed by dust and gases depends on various factors such as the distance of the supernova, the amount and distribution of intervening dust and gas, and the specific properties of the light emitted.
In general, when a supernova occurs relatively close to us, the initial flash of light can indeed reach us before it encounters significant absorption or scattering by interstellar dust and gas. However, as the light travels through space, it may interact with dust particles or encounter gas clouds, which can scatter or absorb certain wavelengths of light.
The degree of absorption or scattering depends on the composition and density of the dust and gas, as well as the wavelength of the light. Dust tends to scatter shorter wavelengths (such as blue and ultraviolet light) more than longer wavelengths (such as red and infrared light). Thus, the initial flash of a supernova, which is typically rich in shorter wavelengths, may experience more absorption and scattering compared to later, more redshifted emission.
In some cases, the light from a supernova can be partially or completely obscured by intervening dust and gas, leading to a phenomenon known as "extinction." This can affect our ability to observe and study the supernova across different wavelengths.
However, it's worth noting that even if the initial flash is absorbed or scattered, subsequent emission from the expanding supernova remnant, including the shock wave interacting with surrounding material, can continue to produce light that may reach us over an extended period of time.
In summary, the extent to which light from an exploding star gets absorbed or scattered by dust and gases before reaching us depends on several factors. While the initial flash may be subject to some absorption or scattering, subsequent emission from the supernova remnant can still be observed and studied, providing valuable insights into the explosion and its aftermath.