robin_a In my searches I've noticed this review paper from a couple of years ago for type IIn.
https://arxiv.org/pdf/2107.02179
It's not so much the reading of it that's needed (which is worthwhile in itself), it's the fact that in defniing the true SN IIn from other purported SN IIn the papers includes a lorra, lorra IIn spectral plots, including for some as evolving time series. And it's primarily a spectroscopic assesssment/review.
I think I saw this SN being classed as SN IIb on S&T (well, n is next to b on the keyboard). This is very strange given that apparently a lack of hydrogen lines to speak of, especially Halpha, is a major diagnostic of IIb. Unless I misread it.
Can't find a good lightcurve, but I think it will slow down in brightness now, maybe spend a couple of days crawling up a notch or two, rate of change itself declining, peaking around a fortnight into the outburst and then after three weeks start a crawling fade, with possible blips if more circumstellar shells are hit. However, I haven't found a long term lightcurve for one so am not sure of the decline profile, nor its typical rate. As the things are apparently not caused by a sole type of progenitor their decay lightcurves likely aren't homogenous anyway, likely dependent on density, morphology and relative orientation of the latter of the circumstellar material.
The latter could lead to a chance of light echoes appearing in time, as does the object's position near a HII region, so that would be a nice distance scale adjunct to the ladder, as I believe those can give quite precise distances.
I hope this fortnight level off idea is accurate, I won't have a chance to look at it before the weekend, when the Moon may just start to be a big enough interference for me, given no true night nowadays anyway and light pollution.
Edited by yuzameh, 22 May 2023 - 12:13 PM.