Supernovas of the Ia type and measurements of the cosmological parameters

It is the night that it is beautiful to believe in the light. Edmond Rostand

As we saw in chapter 5 taught us that the supernovæ of the Ia type had this property to have a maximum of luminosity very homogeneous of one supernova to the other.

In the filter B in particular, these objects have a dispersion of luminosity from approximately 50%, that is to say an uncertainty in the measurement of distance from 25%.

This remarkable homogeneity does not make it possible however to make precise measurements of distance. However, we will see in the continuation, how starting from the properties of the lightcurve, it is possible to reduce this dispersion. In particular, we will explain how the shape of the lightcurve allows `` to standardize '' the supernovæ of the Ia type.

Lastly, we will discuss the principal effects being able to bias measurements of distance from these supernovæ.