%0 Journal Article 
%A Pastorello, A.
%A Mason, E.
%A Taubenberger, S.
%A Fraser, M.
%A Cortini, G.
%A Tomasella, L.
%A Botticella, M.T.
%A Elias-Rosa, N.
%A Kotak, R.
%A Smartt, S.J.
%A Benetti, S.
%A Cappellaro, E.
%A Turatto, M.
%A Tartaglia, L.
%A Djorgovski, S.G.
%A Drake, A.J.
%A Berton, M.
%A Briganti, F.
%A Brimacombe, J.
%A Bufano, F.
%A Cai, Y.-Z.
%A Chen, S.
%A Christensen, E.J.
%A Ciabattari, F.
%A Congiu, E.
%A Dimai, A.
%A Inserra, C.
%A Kankare, E.
%A Magill, L.
%A Maguire, K.
%A Martinelli, F.
%A Morales Garoffolo, Antonia Isabel
%A Ochner, P.
%A Pignata, G.
%A Reguitti, A.
%A Sollerman, J.
%A Spiro, S.
%A Terreran, G.
%A Wright, D.E.
%T Luminous Red Novae: Stellar Mergers or Giant Eruptions?
%D 2019
%@ 1432-0746
%U http://hdl.handle.net/10498/21782
%X We present extensive datasets for a class of intermediate-luminosity optical transients known as luminous red novae. They show double-peaked light curves, with an initial rapid luminosity rise to a blue peak (at -13 to -15 mag), which is followed by a longer-duration red peak that sometimes is attenuated, resembling a plateau. The progenitors of three of them (NGC 4490-2011OT1, M 101-2015OT1, and SNhunt248), likely relatively massive blue to yellow stars, were also observed in a pre-eruptive stage when their luminosity was slowly increasing. Early spectra obtained during the first peak show a blue continuum with superposed prominent narrow Balmer lines, with P Cygni profiles. Lines of Fe II are also clearly observed, mostly in emission. During the second peak, the spectral continuum becomes much redder, H alpha is barely detected, and a forest of narrow metal lines is observed in absorption. Very late-time spectra (similar to 6 months after blue peak) show an extremely red spectral continuum, peaking in the infrared (IR) domain. H alpha is detected in pure emission at such late phases, along with broad absorption bands due to molecular overtones (such as TiO, VO). We discuss a few alternative scenarios for luminous red novae. Although major instabilities of single massive stars cannot be definitely ruled out, we favour a common envelope ejection in a close binary system, with possibly a final coalescence of the two stars. The similarity between luminous red novae and the outburst observed a few months before the explosion of the Type IIn SN 2011ht is also discussed.
%K binaries
%K close
%K stars
%K winds
%K outflows
%K supernovae
%K massive
%~ Universidad de Cádiz