Search Publications
Studying the Physical Parameters of the Stellar Binary System Hip 42455 (HD 73900)
Abu-Dhaim, A.; Taani, A.; Tanineah, D. +3 more
We present the results of the combined spectrophotometric and dynamic analysis for the close visual binary star Hip 42455 (HD 73900, I 314). A model binary that consists of two main sequence stars with a clear magnitude difference, but completely different estimations of their spectral types, and different parallax measurements given by the four c…
Speckle Observations with PISCO in Calern (France): Orbit and Mass Determinations for 22 Visual Binaries
Bendjoya, P.; Rivet, J. -P.; Ling, J. F. +7 more
This paper presents orbits and masses for 22 visual double stars, partly derived using their last observations made with the speckle camera PISCO. For 13 of them we have determined their first-time orbits. Masses were calculated from Hipparcos and Gaia parallaxes when available, and from dynamical parallaxes otherwise. They are compared with masse…
Roche Modeling and Evolutionary History of Multiple Low Mass Contact Binary Systems
Stępień, K.; Alton, K. B.
The Northern Sky Variable Survey (NSVS) has been a rich source of variable stars many of which have only been studied to a limited extent. Herein we describe five eclipsing binary systems that were first detected by the ROTSE-I telescope and ultimately shown to be low mass contact binaries. Photometric data (B, V and Ic) acquired from M…
GT Ursae Majoris AB - a Possible Quadruple System
Kamiński, K.; Dimitrov, W.; Polińska, M. +3 more
We present the first spectroscopic study of an eclipsing system GT UMa. Our spectra show that the main visual component A is a triple-lined star, which consists of a close eclipsing pair and a farther third component. Radial velocity measurements show evidence of reflex motion. We used Hipparcos and our own R-band light curves for the analysis. Th…
The Study of Triple Systems V949 Cen, V358 Pup and V1055 Sco
Mašek, M.; Zasche, P.; Juryšek, J. +1 more
The systems V949 Cen, V358 Pup, and V1055 Sco are triples comprised of an eclipsing binary orbiting with a distant visual component on a much longer orbit. The first detailed photometric analysis of these interesting systems was performed using also the archival data from Hipparcos, ASAS, SuperWASP, OMC, and Pi of the Sky surveys. The system V358 …
The Period and the Cause of Variability of the Magnetic Ap Star V473 Tauri
Jerzykiewicz, M.
The ground based UBV observations and Hipparcos Hp magnitudes of this well known magnetic variable are analyzed. The period of the star's light variation is improved. The improved value, accounting for the available photometric data from the 1963--1964 Lowell observations of Rakosch to the 1990--1993 Hp magnitudes, is equal to 1.4068541±0.0000029 …
Spectroscopic Study of Kepler Asteroseismic Targets
Frasca, A.; Latham, D. W.; Jerzykiewicz, M. +1 more
Reported are spectroscopic observations of 15 candidates for Kepler primary asteroseismic targets and 14 other stars in the Kepler field, carried out at three observatories. For all these stars, the radial velocities, effective temperature, surface gravity, metallicity, and the projected rotational velocity are derived from two separate sets of da…
Frequency of Hot Jupiters and Very Hot Jupiters from the OGLE-III Transit Surveys toward the Galactic Bulge and Carina
Udalski, A.; Gould, A.; Gaudi, B. S. +1 more
We derive the frequencies of hot Jupiters (HJs) with 3-5 day periods and very hot Jupiters (VHJs) with 1-3 day periods by comparing the planets actually detected in the OGLE-III survey with those predicted by our models. The models are constructed following Gould and Morgan (2003) by populating the line of sight with stars drawn from the Hipparcos…
New beta Cephei and SPB Stars Discovered in Hipparcos Photometry
Molenda-Zakowicz, J.; Polubek, G.
We discuss 34 stars for which we detected new frequencies in Hipparcos Hp magnitudes. 13 of these stars are variables discovered in this paper. For 20 stars, we derive log T_eff and log g from Stromgren or Geneva photometry.
We classify one new beta Cep star, HIP 88352, two new beta Cep suspects, HIP 54753 and 88123, four new SPBs, HIP 1030, …Empirical Absolute Magnitudes, Luminosities and Effective Temperatures of SPB Variables and the Problem of Variability Classification of Monoperiodic Stars
Molenda-Zakowicz, J.; Polubek, G.
We derive semi--empirical log L/Lodot for 27 stars classified as SPB on the basis of Hipparcos photometry and we plot these stars on the log Teff-log L/Lodot diagram. We confirm pulsations of HIP 63210 and HIP 108348 and show that luminosities and masses derived from photometry are of limited use for asteroseismolo…