Related papers: Inferred timescales for common envelope ejection u…

Astrometry from {\it Gaia} DR3 has enabled the discovery of a sample of 3000+ binaries containing white dwarfs (WD) and main-sequence (MS) stars in relatively wide orbits, with orbital periods $P_{\rm orb} = (100-1000)$ d. This population…

The presence of a close, low-mass companion is thought to play a substantial and perhaps necessary role in shaping post-Asymptotic Giant Branch and Planetary Nebula outflows. During post-main-sequence evolution, radial expansion of the…

The single-degenerate (SD) model is one of the leading models for the progenitors of Type Ia supernovae (SNe Ia). Recently, a new version of the SD model, the common-envelope wind (CEW) model, has been proposed, which, in principle, has the…

I propose that at the termination of the common envelope evolution (CEE) the companion to the giant star might launch jets that have variable directions and intensities, hence the jets shape the inner zones of the descendant nebula causing…

After the initial fast spiral-in phase experienced by a common-envelope binary, the system may enter a slow, self-regulated phase, possibly lasting 100s of years, in which all the energy released by orbital decay can be efficiently…

We present a systematic study of the evolution of low- and intermediate-mass X-ray binaries (L/IMXBs) consisting of a $1.4\,M_{\odot}$ neutron star (NS) and a donor star of mass $1-8\,M_{\odot}$. Using grids of detailed MESA simulations, we…

The recently detected gravitational wave signals (GW150914 and GW151226) of the merger event of a pair of relatively massive stellar-mass black holes (BHs) calls for an investigation of the formation of such progenitor systems in general.…

Mergers of neutron stars (NSs) and black holes (BHs) are nowadays observed routinely thanks to gravitational-wave (GW) astronomy. In the isolated binary-evolution channel, a common-envelope (CE) phase of a red supergiant (RSG) and a compact…

This work aims to present our current best physical understanding of common-envelope evolution (CEE). We highlight areas of consensus and disagreement, and stress ideas which should point the way forward for progress in this important but…

During post-main-sequence evolution, radial expansion of the primary star, accompanied by intense winds, can significantly alter the binary orbit via tidal dissipation and mass loss. The fate of a given binary system is determined by the…

Massive stars commonly form binaries that can evolve into compact systems via common envelope evolution (CEE), a critical but poorly understood phase -- especially when the companion is a neutron star. Understanding the drag force exerted…

As part of an ongoing collaboration between student groups at high schools and professional astronomers, we have searched for the presence of circum-binary planets in a bona-fide unbiased sample of twelve post-common envelope binaries…

Close binary systems are the progenitors to both Type Ia supernovae and the compact object mergers that can be detected via gravitational waves. To achieve a binary with a small radial separation, it is believed that the system likely…

I find the common envelope (CE) energy formalism, the CE \alpha-prescription, to be inadequate to predict the final orbital separation of the CE evolution in massive envelopes. I find that when the orbital separation decreases to ~10 times…

Post-common envelope binaries (PCEBs) consisting of a white dwarf (WD) plus a main-sequence (MS) star can constrain current prescriptions of common envelope evolution (CEE) and calibrate theoretical models of binary formation and evolution.…

We measure the mass distribution of main-sequence (MS) companions to hot subdwarf B stars (sdBs) in post-common envelope binaries (PCEBs). We carried out a spectroscopic survey of 14 eclipsing systems ("HW Vir binaries") with orbital…

Most planetary nebulae (PNe) show beautiful, axisymmetric morphologies despite their progenitor stars being essentially spherical. Close binarity is widely invoked to help eject an axisymmetric nebula, after a brief phase of engulfment of…

We reconstruct the common envelope (CE) phase for the current sample of observed white dwarf-main sequence post-common envelope binaries (PCEBs). We apply multi-regression analysis in order to investigate whether correlations exist between…

We discuss the evolution of binaries with moderately high masses (about 10 - 30 solar masses), and with periods of about 3 - 300d, corresponding mostly to early Case B. These are usually thought to evolve either by reasonably conservative…

We analyze the orbital period distribution of post-common-envelope white-dwarf-main-sequence (WDMS) binaries by cross-matching the new spectroscopic Gaia DR3 WDMS catalog with TESS light curves, and applying a uniform periodicity search and…