Related papers: Absolute properties of the neglected eclipsing B-t…
In this work, we study a heterogeneous group of seven stellar systems for the first time. Despite their different distances or spectral types, all of them belong to a very rare group of quadruple systems of 2+2 architecture, where both of…
We report the discovery of an eclipsing binary - HS 0705+6700 - being an sdB star with a faint companion. From its light curve the orbital period of 8263.87 s, the mass ratio of the system q = 0.28, the inclination of 84.4 deg and other…
The O6 Vn star HD 64315 is believed to belong to the star-forming region known as NGC 2467, but previous distance estimates do not support this association. We explore the multiple nature of this star with the aim of determining its…
We present a photometric and spectroscopic study of HD 50526, an ellipsoidal binary member of the group Double Periodic Variable stars. Performing data-mining in photometric surveys and conducting new spectroscopic observations with several…
New photometric, spectroscopic, and eclipse timing observations of the eclipsing binary star HP Aur allow for very accurate orbital determinations, even in the presence of a third body and transient starspot activity. The eclipsing binary…
We use ASAS V-band and ASAS-SN g-band observations to model the long-period detached eclipsing binary ASASSN-21co. ASAS observations show an eclipse of depth V ~ 0.6 mag in April of 2009. ASAS-SN g-band observations from March of 2021 show…
We identify the bright Am-type star HD 181793 to be a previously-unknown eclipsing, chemically peculiar heartbeat binary, the second of its kind known. The system carries an orbital period of $P = 11.47578275 \pm 0.00000055$ days. We use…
Context. Most massive stars are in binary or multiple systems. Several massive stars have been detected as doublelined spectroscopic binaries and among these, the OWN Survey has detected a non-negligible number whose components show very…
The Procyon AB binary system (orbital period 40.838 years, a newly-refined determination), is near and bright enough that the component radii, effective temperatures, and luminosities are very well determined, although more than one…
GT\,Cep is a semi-detached close binary system with an orbital period of 4.91 days, containing a massive star. I have obtained spectroscopic observations and derived radial velocities of both components. Combining the analyses of radial…
Among the competing evolution theories for subdwarf-B (sdB) stars is the binary evolution scenario. EC~20117-4014 (=V4640~Sgr) is a spectroscopic binary system consisting of a pulsating sdB star and a late F main-sequence companion…
The purpose of this work is to extend a sample of accurately modeled, benchmark-grade eclipsing binaries with accurately determined masses and radii. We select four "well-behaved" Kepler binaries, KIC2306740, KIC4076952, KIC5193386 and…
We present a detailed photometric and spectroscopic analysis of DD CMa, based on published survey photometry and new spectroscopic data. We find an improved orbital period of $P_\mathrm{o}= 2.0084530 \pm 0.0000006 ~\mathrm{d}$. Our spectra…
We report new spectroscopic and photometric observations of the main-sequence, detached, eccentric, double-lined eclipsing binary V541 Cyg (P = 15.34 days, e = 0.468). Using these observations together with existing measurements we…
We present the physical properties of the eclipsing binary V2281 Cyg, which shows a light-time effect due to a supposed tertiary component from its eclipse timing variation according to the $Kepler$ observations. The high-resolution spectra…
We present results from the most recent (2002-2004) observing campaigns of the eclipsing system KH 15D, in addition to re-reduced data obtained at Van Vleck Observatory (VVO) between 1995 and 2000. Phasing nine years of photometric data…
Thirteen spectroscopic orbits of late-type stars are determined from the high-resolution spectra taken with the CHIRON echelle spectrometer at the 1.5-m CTIO telescope. Most (HIP 14194B, 40523A, 41171A, 51578A, 57572B, 59426A, 62852B,…
We present the results of optical wavelength observations of the unusual SMC eclipsing binary system HD 5980 obtained in 1999 and 2004--2005. Radial velocity curves for the erupting LBV/WR object (star A) and its close WR-like companion…
HD~143811~AB is the host star to the directly imaged planet HD~143811~AB~b, which was recently discovered using data from the Gemini Planet Imager and Keck NIRC2. A member of the Sco-Cen star-forming region with an age of $13 \pm 4$ Myr,…
V583 Lyr is an extremely low mass ratio Algol-type binary with an orbital period of 11.2580 days. We determined an effective temperature of T_{eff1} = 9000 \pm 350 K from newly observed spectra, which might be an underestimate due to binary…