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We present the results of a detailed analysis of 121 ground-based high-resolution high S/N spectroscopic measurements spread over 3 years for the Beta Cephei star Theta Ophiuchi. We discovered Theta Oph to be a triple system. In addition to…

Astrophysics · Physics 2009-11-13 M. Briquet , K. Lefever , K. Uytterhoeven , C. Aerts

Context. The nearby multiple system delta Velorum contains a widely detached eclipsing binary and a third component. Aims. We take advantage of this system offering the opportunity to determine the set of fundamental parameters (masses,…

Solar and Stellar Astrophysics · Physics 2015-05-20 T. Pribulla , A. Merand , P. Kervella , M. Vaňko , I. R. Stevens , R. Chini , V. Hoffmeister , O. Stahl , A. Berndt , M. Mugrauer , M. Ammler-von Eiff

The Gamma Cephei planetary system is one of the most interesting systems due to several reasons: 1.) it is the first planet candidate detected by precise radial velocity (RV) measurements that was discussed in the literature (Campbell et…

Earth and Planetary Astrophysics · Physics 2015-03-17 Michael Endl , William D. Cochran , Artie P. Hatzes , Robert A. Wittenmyer

We provide a complete characterization of the astrophysical properties of the $\sigma$ Ori Aa,Ab,B hierarchical triple system, and an improved set of orbital parameters for the highly eccentric $\sigma$ Ori Aa,Ab spectroscopic binary. We…

The prototype of the Beta Cep class of pulsating stars, Beta Cep, rotates relatively slowly, and yet displays episodic Halpha emission. Such behaviour is typical of a classical Be star. For some time this posed a contradiction to our…

Solar and Stellar Astrophysics · Physics 2009-11-13 H. E. Wheelwright , R. D. Oudmaijer , R. S. Schnerr

Context. Only a few open clusters are as important for the study of stellar and substellar objects, and their formation and evolution, as the young sigma Orionis cluster. However, a complete spectroscopic characterisation of its whole…

Solar and Stellar Astrophysics · Physics 2019-09-18 J. A. Caballero , A. de Burgos , F. J. Alonso-Floriano , A. Cabrera-Lavers , D. Garcia-Alvarez , D. Montes

We have imaged seventeen recently discovered Sirius-like binary systems with HST/WFPC2 and resolved the white dwarf secondary in eight cases. Most of the implied orbital periods are of order several hundred years, but in three cases (56…

Astrophysics · Physics 2007-05-23 Matt Burleigh , Martin Barstow , Howard E. Bond , Jay Holberg

High-dispersion spectroscopy of EY Cyg obtained from data spanning twelve years show, for the first time, the radial velocity curves from both emission and absorption line systems, yielding semi-amplitudes K_{em}=24+/- 4 km s^-1 and…

Astrophysics · Physics 2009-11-11 J. Echevarria , R. Michel , R. Costero , S. Zharikov

We present a spectroscopic characterisation and a new orbital solution for the binary system beta Cyg Aa/Ac (MCA 55), the primary component (beta Cyg A) of the well-known wide double star Albireo. By matching evolutionary tracks to the…

Located in the Orion Trapezium cluster, Theta 1 Orionis C is one of the youngest and nearest high-mass stars (O5-O7) and also known to be a close binary system. Using new multi-epoch visual and near-infrared bispectrum speckle…

In anticipation of the possible collision between a circumstellar disk and the secondary star in the highly eccentric binary system Delta Scorpii, high angular resolution interferometric observations have been acquired aimed at revising the…

Solar and Stellar Astrophysics · Physics 2015-05-27 C. Tycner , A. Ames , R. T. Zavala , C. A. Hummel , J. A. Benson , D. J. Hutter

We present measures for 10 pairs in the constellation of Scorpius using a C14 telescope, Lucky Imaging, and the Reduc software. The separations of Alpha Centauri AB, as determined from the orbital elements of Pourbaix and Boffin (2016),…

Instrumentation and Methods for Astrophysics · Physics 2020-03-17 Matthew James , Meg Emery , Graeme L. White , Roderick Letchford , Stephen Bosi

V1022 Cas has been known as a spectroscopic binary for a century. It was found to be eclipsing based on photometry from the Hipparcos satellite, and an astrometric orbit was recently obtained from near-infrared interferometry. We present…

Solar and Stellar Astrophysics · Physics 2020-12-22 John Southworth

Aims. We aim to characterize the properties of the inner companion of the S-type AGB star pi1 Gru and to identify plausible future evolutionary scenarios for this triple system. Methods. We observed pi1 Gru with ALMA and VLT/SPHERE. In…

We aim to revisit the system AB Pic which has a known companion at the exoplanet/ brown-dwarf boundary. We based this study on a rich set of observations to investigate the companion's orbit and atmosphere. We composed a spectrum of AB Pic…

Precision radial velocity measurements of the Gamma Cephei (HR8974) binary system suggest the existence of a planetary companion with a minimum mass of 1.7 Jupiter-mass on an elliptical orbit with a ~2.14 AU semimajor axis and 0.12…

Astrophysics · Physics 2009-11-10 Nader Haghighipour

We present the results of photometric and spectroscopic follow-ups of the lowest mass member candidates in the nearest OB association, Upper Scorpius (5-10 Myr; 145+/-17 pc), with the Gran Telescopio de Canarias (GTC) and European Southern…

Solar and Stellar Astrophysics · Physics 2017-11-15 N. Lodieu , M. R. Zapatero Osorio , V. J. S. Bejar , K. Pena Ramirez

Classical Cepheid variable stars are crucial calibrators of the cosmic distance scale thanks to a relation between their pulsation periods and luminosities. Their archetype, {\delta} Cephei, is an important calibrator for this relation. In…

We present new 0.9-2.45 $\mu$m spectroscopy ($R \sim 1000$), and $Y$, $J$, $H$, $K_s$, $L^\prime$ photometry, obtained at Gemini North, of three low-mass brown dwarf companions on wide orbits around young stars of the Upper Scorpius OB…

We present the spectroscopic orbits of eleven nearby, mid-to-late M dwarf binary systems in a variety of configurations: two single-lined binaries (SB1s), seven double-lined binaries (SB2s), one double-lined triple (ST2), and one…