Related papers: The subdwarf B + white dwarf binary KPD 1930+2752 …
The delayed-detonation explosion mechanism applied to a Chandrasekhar-mass white dwarf offers a very attractive model to explain the inferred characteristics of Type Ia supernovae (SNe Ia). The resulting ejecta are chemically stratified,…
Over-luminous type Ia supernovae (SNe Ia) show peculiar observational features, for which an explosion of a super-massive white dwarf (WD) beyond the classical Chandrasekhar-limiting mass has been suggested, largely based on their high…
The masses of compact objects like white dwarfs, neutron stars and black holes are fundamental to astrophysics, but very difficult to measure. We present the results of an analysis of subluminous B (sdB) stars in close binary systems with…
The progenitors of supernovae (SNe) type Ia are usually assumed to be either a single white dwarf (WD) accreting from a non-degenerate companion (the SD channel) or the result of two merging WDs (DD channel). However, no consensus currently…
We present nebular spectroscopy of SN 2020hvf, a Type Ia supernova (SN Ia) with an early bump in its light curve. SN 2020hvf shares many spectroscopic and photometric similarities to the carbon-rich high-luminosity "03fg-like" SNe Ia. At…
We investigate the contribution to the formation of type Ia supernovae of the single (a white dwarf accreting from a non-degenerate companion) and double (two merging white dwarfs) degenerate scenario, as well as various aspects of the…
Howell et al. have reported the discovery of SN Ia SN 2003fg (SNLS-03D3bb) and conclude that SN 2003fg is very likely a super-Chandrasekhar-mass SN Ia perhaps with a mass of order 2 solar masses. Their work is the first strong evidence that…
The single-degenerate channel for the progenitors of type Ia supernovae (SNe Ia) are currently accepted, in which a carbon-oxygen white dwarf (CO WD) accretes hydrogen-rich material from its companion, increases its mass to the…
Context: Superluminous type Ia supernovae (SNe Ia) may be explained by super-Chandrasekhar-mass explosions of rapidly rotating white dwarfs (WDs). In a preceding paper, we showed that the deflagration scenario applied to rapidly rotating…
The recently proposed "dynamically driven double-degenerate double-detonation" (D6) scenario posits that Type Ia supernovae (SNe) may occur during dynamically unstable mass transfer between two white dwarfs (WDs) in a binary. This scenario…
Is the Chandrasekhar mass limit for white dwarfs (WDs) set in stone? Not anymore -- recent observations of over-luminous, peculiar type Ia supernovae can be explained if significantly super-Chandrasekhar WDs exist as their progenitors, thus…
We explore properties of Type Ib and IIb SN progenitors that are produced by stable mass transfer in binary systems, using a new grid of stellar evolution models from an initial primary mass in the range of 10 - 18 $\mathrm{M_\odot}$ at…
We present and discuss the radio observations of 27 Type Ia supernovae (SNe Ia) observed over two decades with the Very Large Array. No SN Ia has been detected so far in the radio, implying a very low density for any possible circumstellar…
The explosion of a Type Ia supernova, SN 2011ef, in the nearby Pinwheel galaxy (M101 at 6.4 Mpc) provides an opportunity to study pre-explosion images and search for the progenitor, which should consist of a white dwarf (WD), possibly…
We present a theoretical delay time distribution (DTD) of Type Ia supernovae on the basis of our new evolutionary models of single degenerate (SD) progenitor systems. Our model DTD has almost a featureless power law shape (\propto t^{-n}…
Although Type Ia supernovae (SNe Ia) are a major tool in cosmology and play a key role in the chemical evolution of galaxies, the nature of their progenitor systems (apart from the fact that they must contain at least one white dwarf, that…
Even though Type Ia supernovae (SNIa) play an important role in many fields in astronomy, the nature of the progenitors of SNIa remain a mystery. One of the classical evolutionary pathways towards a SNIa explosion is the single degenerate…
We present an analysis of the close double degenerate NLTT 12758, which is comprised of a magnetic white dwarf with a field of about 3.1 MG and an apparently non-magnetic white dwarf. We measured an orbital period of 1.154 days and found…
The dynamically-driven double-degenerate double-detonation model has emerged as a promising progenitor candidate for Type Ia supernovae. In this scenario, the primary white dwarf ignites due to dynamical interaction with a companion white…
We explore collisions between two white dwarfs as a pathway for making Type Ia Supernovae (SNIa). White dwarf number densities in globular clusters allow 10-100 redshift <1 collisions per year, and observations by (Chomiuk et al. 2008) of…