Related papers: Geometry of the Draco C1 Symbiotic Binary
Brown dwarfs and giant planets orbiting close to a host star are subjected to significant irradiation that can modify the properties of their atmospheres. In order to test the atmospheric models that are used to describe these systems, it…
The symbiotic star R Aqr is part of a small sample of binary AGB stars observed with ALMA. The sample stars are: R Aqr, Mira, W Aql, and pi1 Gru. The sample covers a range in binary separation and wind properties, where R Aqr is the source…
In this work, the photometric data from the American Association of Variable Star Observers are collected and analyzed on the SX Phoenicis star DY Pegasi (DY Peg). From the frequency analysis, we get three independent frequencies: $f_0 =…
Binaries of two white dwarfs (WDs) are an important class of astrophysical objects that are theorized to lead to Type Ia supernovae and are also used to gain insight into complex processes involved in stellar binary evolution. We report the…
This is a preliminary analysis of the orbital parameters of the well known eclipsing symbiotic binary, SY Muscae. It is a system composed of a white dwarf (WD) and a red giant (RG), located in the southern sky. With the use of photometric…
Symbiotic binaries are long period interacting binaries consisting of a white dwarf (WD) accreting material from a cool evolved giant star via stellar winds. In this paper we study the symbiotic binary LIN 358 located in the SMC. We have…
We report spectroscopic and photometric follow-up of a dormant black hole (BH) candidate from Gaia DR3. The system, which we call Gaia BH2, contains a $\sim 1M_{\odot}$ red giant and a dark companion with mass $M_2 = 8.9\pm 0.3\,M_{\odot}$…
The magnetic white dwarf SDSS J121209.31+013627.7 exhibits a weak, narrow Halpha emission line whose radial velocity and strength are modulated on a period of ~90 minutes. Though indicative of irradiation on a nearby companion, no cool…
Near-infrared spectroscopic surveys have uncovered a population of short-period, blended-light spectral binaries composed of low-mass stars and brown dwarfs. These systems are amenable to orbit determination and individual mass measurements…
We have found a system listed in the Kepler Binary Catalog (3.273 day period; Prsa et al. 2010) that we have determined is comprised of a low-mass, thermally-bloated, hot white dwarf orbiting an A star of about 2.3 solar masses. In this…
Subdwarf B stars are core-helium burning stars located on the extreme horizontal branch. Extensive mass loss on the red giant branch is necessary to form them. It has been proposed that substellar companions could lead to the required…
We present two epochs of radial velocities of the first imaged T dwarf Gliese 229B obtained with Keck/NIRSPEC. The two radial velocities are discrepant with one another, and with the radial velocity of the host star, at $\approx$$11\sigma$…
The well studied carbon star V Hydrae is known to exhibit a complex asymmetric environment made of a dense equatorial wind and high-velocity outflows, hinting at its transition from the AGB phase to the asymmetric planetary nebula phase. In…
A periodic variation in the pulse timings of the pulsating hot subdwarf B star CS 1246 was recently discovered via the O-C diagram and suggests the presence of a binary companion with an orbital period of two weeks. Fits to this phase…
Draco dwarf Spheroidal galaxy (dSph) is one of the nearest and the most dark matter dominated satellites of the Milky Way. We obtained multi-epoch near-infrared (NIR, $JHK_s$) observations of the central region of Draco dSph covering a sky…
In this study, we conducted a comprehensive analysis of the SX Phoenicis (SX Phe) type star CY Aquarii (CY Aqr). Our investigation included a detailed $O-C$ analysis based on a 90-year observational dataset, augmented by 1,367 newly…
We created the APOGEE-GALEX-\emph{Gaia} catalog to study white dwarfs binaries. This database aims to create a minimally biased sample of WD binary systems identified from a combination of GALEX, {\it Gaia}, and APOGEE data to increase the…
We present Lick Natural Guide Star Adaptive Optics observations of the L8 brown dwarf Gliese 337C, which is resolved for the first time into two closely separated (0"53+/-0"03), nearly equal magnitude components with a K_s flux ratio of…
We present results of period analysis of ASAS, MACHO and OGLE light curves of 79 symbiotic stars classified as S and D'-type. The light curves of 58 objects show variations with the orbital period. In case of 34 objects, orbital periods are…
Binary systems consisting of a white dwarf and a main-sequence companion with orbital periods up to $\approx 100$ d are often thought to be formed through common envelope evolution which is still poorly understood. To provide new…