Related papers: Runaway Coalescence at the Onset of Common Envelop…
We study the process of runaway, unstable Roche lobe overflow in coalescing binary systems and its dependence on the properties of the binary involved. We create three-dimensional hydrodynamic models of binary coalescences, and follow them…
Binary systems undergoing unstable Roche Lobe overflow spill gas into their circumbinary environment as their orbits decay toward coalescence. In this paper, we use a suite of hydrodynamic models of coalescing binaries involving an extended…
Recent observations have revealed that the remnants of stellar-coalescence transients are bipolar. This raises the questions of how these bipolar morphologies arise and what they teach us about the mechanisms of mass ejection during stellar…
Luminous red novae trace unstable binary interactions in which common-envelope evolution can produce either a stellar merger or a surviving binary following envelope ejection. Recent population studies suggest that a substantial fraction of…
This paper investigates the recent stellar merger transient M31LRN 2015 in the Andromeda galaxy. We analyze published optical photometry and spectroscopy along with a Hubble Space Telescope detection of the color and magnitude of the…
A common-envelope (CE) phase occurs when a star engulfs its companion and is widely considered the primary channel for producing Luminous Red Novae (LRNe). In this study, we combine binary-population synthesis with stellar-evolution…
Tidal dissipation due to turbulent viscosity in the convective regions of giant stars plays an important role in shaping the orbits of pre-common envelope systems. Such systems are possible sources of transients and close compact binary…
High rates of stable mass transfer likely occur for some binary star systems, but the resulting flow of mass and angular momentum (AM) is unclear. We perform hydrodynamical simulations of a polytropic donor star and a point mass secondary…
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…
Red novae or luminous red novae are a class of optical transients that have emerged over the past two decades. They occupy an intermediate luminosity regime between classical novae and supernovae and are characterized by cool, slowly…
We present 3D radiation hydrodynamics simulations of common-envelope (CE) evolution involving a 12 solar mass red supergiant donor and a 3 solar mass companion. Existing 3D simulations are predominantly adiabatic, focusing strongly on…
High rates of stable mass transfer (MT) occur for some binary star systems, resulting in luminous transients and circumbinary outflows (CBOs). We perform hydrodynamical simulations of a $10 \ M_\odot$ donor star and a $5\ M_\odot$ point…
We discuss the central role that dust condensation plays in shaping the observational appearance of outflows from coalescing binary systems. As binaries begin to coalesce, they shock-heat and expel material into their surroundings.…
Some binary stars experience common envelope evolution, which is accompanied by drastic loss of angular momentum, mass, and orbital energy and which leaves behind close binaries often involving at least one white dwarf, neutron star, or…
The hydrodynamic evolution of the common envelope phase of a low mass binary composed of a 1.05 Msun red giant and a 0.6 Msun companion has been followed for five orbits of the system using a high resolution method in three spatial…
The prevalence of binary stars at close separations implies that many of these systems will interact or merge during the binary's lifetime. This paper presents hydrodynamic simulations of the scenario of binary coalescence through unstable…
The hydrogen-rich envelopes accreted by white dwarf stars from their red dwarf companions lead to thermonuclear runaways observed as classical nova eruptions peaking at up to 1 Million solar luminosities. Virtually all nova progenitors are…
T~Coronae Borealis is the nearest symbiotic recurrent nova. Twice in the last two centuries, in 1866 and 1946, the accreted material ignited on the surface of the white dwarf via runaway thermonuclear fusion reactions and produced a nova…
In close binary star systems, common envelope evolution may occur after a previous phase of mass transfer. Some isolated formation channels for double neutron star binaries suggest that the donor of common envelope evolution was the…
The monotonic increase of the radius of low mass stars during their ascent on the red giant branch halts when they suffer a temporary contraction. This occurs when the hydrogen burning shell reaches the discontinuity in hydrogen content…