Raddi, R.Hollands, M.A.Koester, D.Hermes, James J.Gänsicke, B.T.Heber, UlrichShen, K.J.Townsley, D.M.Pala, A.F.Reding, J.S.Toloza, O.F.Pelisoli, I.Geier, S.Gentile Fusillo, Nicola PietroMunari, U.Strader, J.2020-04-132020-04-132019-10-21R. Raddi, M.A. Hollands, D. Koester, J.J. Hermes, B.T. Gänsicke, U. Heber, K.J. Shen, D.M. Townsley, A.F. Pala, J.S. Reding, O.F. Toloza, I. Pelisoli, S. Geier, N.P. Gentile Fusillo, U. Munari, J. Strader. 2019. "Partly burnt runaway stellar remnants from peculiar thermonuclear supernovae." Monthly Notices of the Royal Astronomical Society, Volume 489, Issue 2, pp. 1489 - 1508. https://doi.org/10.1093/mnras/stz16180035-87111365-2966https://hdl.handle.net/2144/40132We report the discovery of three stars that, along with the prototype LP 40−365, form a distinct class of chemically peculiar runaway stars that are the survivors of thermonuclear explosions. Spectroscopy of the four confirmed LP 40−365 stars finds ONe-dominated atmospheres enriched with remarkably similar amounts of nuclear ashes of partial O- and Si-burning. Kinematic evidence is consistent with ejection from a binary supernova progenitor; at least two stars have rest-frame velocities indicating they are unbound to the Galaxy. With masses and radii ranging between 0.20 and 0.28 M⊙ and between 0.16 and 0.60 R⊙, respectively, we speculate these inflated white dwarfs are the partly burnt remnants of either peculiar Type Iax or electron-capture supernovae. Adopting supernova rates from the literature, we estimate that ∼20 LP 40−365 stars brighter than 19 mag should be detectable within 2 kpc from the Sun at the end of the Gaia mission. We suggest that as they cool, these stars will evolve in their spectroscopic appearance, and eventually become peculiar O-rich white dwarfs. Finally, we stress that the discovery of new LP 40−365 stars will be useful to further constrain their evolution, supplying key boundary conditions to the modelling of explosion mechanisms, supernova rates, and nucleosynthetic yields of peculiar thermonuclear explosions.p. 1489 - 1508en-USThis article has been accepted for publication in Monthly Notices of the Royal Astronomical Society, Volume 489, Issue 2, pp. 1489 - 1508. © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Stars: individual: LP 40-365SubdwarfsSupernovae: generalWhite dwarfsGalaxy: kinematics and dynamicsSolar and stellar astrophysicsAstronomical and space sciencesAstronomy & astrophysicsArticle10.1093/mnras/stz1618432816