That makes sense. As opposed to a main-sequence nova, in which a very-late-sequence star goes through the advanced burning phases, with fusion progressively of

That makes sense. As opposed to a main-sequence nova, in which a very-late-sequence star goes through the advanced burning phases, with fusion progressively of carbon, neon, oxygen, and finally silicon (to iron) occurs. The final stages of this occur quite quickly, on the order of months, weeks, days, and even hours, as I understand. Whether or not the burning phases can be astronomically observed and predicted I don't know, and was what inspired my question above. <https://ned.ipac.caltech.edu/level5/Sept16/Rauscher/Rauscher4.html https://ned.ipac.caltech.edu/level5/Sept16/Rauscher/Rauscher...> For a 25M star (one 25 times our Sun's mass), these phases last ~0.5 my (helium), ~600 years (carbon), 6 months (neon), 6 days (oxygen), and about a day (silicon). (More massive stars burn much hotter and faster than lighter ones.)