The born again (very late thermal pulse) scenario revisited: The mass of the remnants and implications for V4334 Sgr.

M. M. MILLER BERTOLAMI; L. G. ALTHAUS

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

Blackwell Publishing

Lugar: Oxford; Año: 2007 vol. 380 p. 763 - 770

0035-8711

We present 1D numerical simulations of the very late thermal pulse (VLTP) scenario for a wide range of remnant masses. We show that by taking into account the different possible remnant masses, the observed evolution of V4334 Sgr (a.k.a. Sakurai´s object) can be reproduced within the standard 1D mixing length theory (MLT) stellar evolutionary models without the inclusion of any ad hoc reduced mixing efficiency. Our simulations hint at a consistent picture with present observations of V4334 Sgr. From energetics, and within the standard MLT approach, we show that low-mass remnants (M <~ 0.6Msolar) are expected to behave markedly differently from higher mass remnants (M >~ 0.6Msolar) in the sense that the latter remnants are not expected to expand significantly as a result of the violent H-burning that takes place during the VLTP. We also assess the discrepancy in the born-again times obtained by different authors by comparing the energy that can be liberated by H-burning during the VLTP event.