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Born again/last He flash objects share with V838 Mon an important characteristic: circumstellar material relic of the recent AGB phase. However their rise to maximum is comparatively much slower and the light curve is simpler. But the main differences are: -) the surface chemistry shows dramatic changes during the He flash, with Carbon (among many other dredged-up elements) turning the balance from O-rich to C-rich; V838 Mon didn't share this. -) the redward motion on the HR diagram as a consequence of the He flash does not push the star into the very cool (better to say cold) temperatures V838 Mon has and is still experiencing (published accounts compares SED to that of a T2 brown dwarf, which is a well bit colder than L brown dwarfs). Ulisse Munari On Tue, 23 Sep 2003, Timothy M. Lawlor wrote: > Hi all, > > V838 Mon is indeed an interesting object. What are the main arguments > against it > being a "born-again" type, or like star (e.g. V434 Sgr or V605 Aql)? > V838 Mon has a light curve that sure looks a lot like our "born-again", > models. > > Cheers, > Tim Lawlor
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