Botticella, M. T.
Smartt, S. J.
Djorgovski, S. G.
Drake, A. J.
Christensen, E. J.
Wright, D. E.
AffiliationUniv Arizona, Dept Planetary Sci, Lunar & Planetary Lab
MetadataShow full item record
PublisherEDP SCIENCES S A
CitationPastorello, A., Mason, E., Taubenberger, S., Fraser, M., Cortini, G., Tomasella, L., ... & Benetti, S. (2019). Luminous red novae: Stellar mergers or giant eruptions?. Astronomy & Astrophysics, 630, A75.
JournalASTRONOMY & ASTROPHYSICS
RightsCopyright © ESO 2019
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractWe 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.
VersionFinal published version
SponsorsPRIN-INAF 2017 "Towards the SKA and CTA era: discovery, localisation and physics of transient sources"; Spanish MICINNMinistry of Science and Innovation, Spain (MICINN) [ESP2017-82674-R]; FEDER fundsEuropean Union (EU); China Scholarship CouncilChina Scholarship Council; STFC through an Ernest Rutherford Fellowship; German Research FoundationGerman Research Foundation (DFG) [TRR33]; ERCEuropean Research Council (ERC) ; STFCScience & Technology Facilities Council (STFC) [ST/P000312/1]; NSFNational Science Foundation (NSF) [AST-1313422, AST-1413600, AST-1749235, AST-9987045]; H2020 through an ERC Starting Grant ; Ministry of Economy, Development, and Tourism's Millennium Science Initiative [IC120009]; UK Science and Technology Facilities CouncilScience & Technology Facilities Council (STFC); NSF Telescope System Instrumentation Program (TSIP); Ohio Board of Regents; Ohio State University Office of ResearchOhio State University; National Aeronautics and Space AdministrationNational Aeronautics & Space Administration (NASA); ESO programmes [184. D-1140, 184. D-1151]