HD 74438: a Young Spectroscopic Quadruple as a Possible Progenitor of Supernovae Ia

Type Ia supernovae (SN Ia) are amongst the most energetic events in the Universe. They are used as standard candles to measure cosmological distances and they produce a rich nucleosynthesis; they are fundamental objects to understand the chemical evolution of galaxies. It is thought that SN Ia are produced by processes occurring in tight binaries including at least one carbon–oxygen white dwarf (WD). Such binaries could emerge from the dynamical evolution of high-multiplicity stellar systems such as the young spectroscopic quadruple HD 74438, recently detected in the Gaia–ESO Survey. Follow-up spectroscopic observations in South Africa and New Zealand, as well as the use of archival ESO spectra, allow us to characterise its orbital and astrophysical parameters. Modelling the dynamical evolution of stellar quadruples shows that such systems can produce WD mergers, possible progenitors of SN Ia.