Hi Robin, thanks a lot for the info about SNID. Did you have to provide the reddening value or the tool automatically adjusts the continuum? If I have understood that correctly, SNID works offline, without a web connection. I'd like to install but I'm not know the Linux environment, I wonder if I could use it on Windows OS using a virtual machine.
The SNID best fit seems also to me related with the two type IIP SN (the profiles are almost identical). Maybe human judgement it is necessary sometime to discard possibile unlikely solutions. Also the SN age is an important constraint.
Excellent achievement Etienne! Concerning your question about finding the minimum of P-Cygni absorption wavelength I think it's a bit risky relying on a particular peak when the random intensity fluctuations are of the same order of magnitude. Anyway, observing the continuum trend in that area, I think it shouldn't be too far from the point you found.
Maybe you already know, here you find a "classical" table that shows the main Sn types:
http://supernova.lbl.gov/~dnkasen/tutor ... _types.jpg
On the bottom the type II with the P-Cygni hydrogen alpha line composed of a broad emission and a narrower blue-shifted absorption. It is just a guideline, each case is in fact different. At present, the emission component of SN2017eaw is the large "bump" well visibile in your spectrum while the blue-shift absorption is difficult for me to identify even on the BAO profile. In the next days/weeks we'll see if the feature becomes appreciable. Expansion velocities measured with P-Cygni tend to decrease over time, so the absorption will be closer to the emission component, either way, it could become more pronounced.
Paolo
