Related papers: Dynamically Forming Extremely Low-Mass White Dwarf…

Common envelope (CE) evolution, which is crucial in creating short period binaries and associated astrophysical events, can be constrained by reverse modeling of such binaries' formation histories. Through analysis of a sample of…

Post-common-envelope binaries (PCEBs) consisting of a white dwarf (WD) and a main-sequence secondary star are ideal systems to constrain models of common-envelope (CE) evolution. Until very recently, observed samples of PCEBs have been too…

Most subdwarf B (sdB) + Helium white dwarf (He WD) binaries are believed to be formed from a particular channel. In this channel, the He WDs are produced first from red giants (RGs) with degenerate cores via stable mass transfer and sdB…

The Extremely Low Mass White Dwarfs (ELM WDs) and pre-ELM WDs are helium core white dwarfs with mass $<\sim 0.3M_{\odot}$. Evolution simulations show that a lower mass limit for ELM WDs exists at $\approx0.14M_{\odot}$ and no one is…

We report the discovery of the first brown dwarf binary system with a Y dwarf primary, WISE J033605.05$-$014350.4, observed with NIRCam on JWST with the F150W and F480M filters. We employed an empirical point spread function binary model to…

EL CVn-type systems represent a rare evolutionary stage in binary star evolution, providing ideal laboratories for investigating stable mass transfer processes and the formation of extremely low-mass white dwarfs (ELM WDs). The Transiting…

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…

We propose a possible binary evolution model for the formation of ultra-long period pulsars (ULPPs). The model involves two key stages: first, a neutron star (NS) in wide binaries undergoes an effective spin-down phase through wind-fed…

Binary pulsar systems are superb probes of stellar and binary evolution and the physics of extreme environments. In a survey with the Arecibo telescope, we have found PSR J1903+0327, a radio pulsar with a rotational period of 2.15 ms in a…

We have carried out numerical evolutionary calculations of binary systems to investigate the formation of binary millisecond pulsars (pulsars with white dwarf companions). We apply the ``standard scenario'' in which the binary pulsars are…

We examine the connections between the current global star formation activity, luminosity, dynamical mass and morphology of galaxies in the Local Volume, using H-alpha data from the 11 Mpc H-alpha and Ultraviolet Galaxy Survey (11HUGS).…

We report our discovery of an extremely rare, low mass, quadruple-lined spectroscopic binary BD-22 5866 (=NLTT 53279, integrated spectral type = M0 V), found during an ongoing search for the youngest M dwarfs in the solar neighborhood. From…

Hot subdwarfs are core-helium burning stars that show lower masses and higher temperatures than canonical horizontal branch stars. They are believed to be formed when a red giant suffers an extreme mass-loss episode. Binary interaction is…

The formation of close massive black-hole binaries is a challenge for binary evolutionary models, especially the intriguing system M33 X-7 which harbours one of the most massive stellar-mass black holes (16 solar masses) orbiting a 70 solar…

We have discovered that the extremely red, low-gravity L7 dwarf 2MASS J11193254-1137466 is a 0.14" (3.6 AU) binary using Keck laser guide star adaptive optics imaging. 2MASS J11193254-1137466 has previously been identified as a likely…

Planets and other low-mass binary companions to stars face a variety of potential fates as their host stars move off the main sequence and grow to subgiants and giants. Stellar mass loss tends to make orbits expand, and tidal torques tend…

In this first in a series of papers related to long-period post-common-envelope (CE) binaries, we investigated whether extra energy is required or not to explain the currently known post-CE binaries with sufficiently long orbital periods…

The formation of brown dwarfs (BDs) poses a key challenge to star formation theory. The observed dearth of nearby ($\leq 5$ AU) brown dwarf companions to solar-mass stars, known as the brown dwarf desert, as well as the tendency for…

The formation of planets in compact or highly eccentric binaries and the migration of hot Jupiters are two outstanding problems in planet formation. The hot Jupiter $\tau$ Boo Ab orbits the primary star in the long-period ($P \gtrsim…

Short-period binary star systems dissipate orbital energy through tidal interactions that lead to tighter, more circular orbits. When at least one star in a binary has evolved off of the main sequence, orbital circularization occurs for…