Supernova 1987A remains the most well-observed and well-studied supernova to date .
Observations produced excellent broad-band photometric and spectroscopic coverage over a wide wavelength range at all epochs .
Here , we focus on the very early spectroscopic observations .
Only recently have numerical models been of sufficient detail to accurately explain the observed spectra .
In SN 1987A , good agreement has been found between observed and synthetic spectra for day one , but by day four , the predicted Balmer lines become much weaker than the observed lines .
We present the results of work based on a radiation-hydrodynamic model by Blinnikov and collaborators .
Synthetic non-LTE spectra generated from this model by the general radiation transfer code PHOENIX strongly support the theory that significant mixing of ^ { 56 } Ni into the outer envelope is required to maintain strong Balmer lines .
Preliminary results suggest a lower limit to the average nickel mass of 1.0 \times 10 ^ { -5 } solar masses is required above 5000 km s ^ { -1 } by day four . PHOENIX models thus have the potential to be a sensitive probe for nickel mixing in the outer layers of a supernova .