Polarisation parameters are presented for 192 radiosources of the B3-VLA sample at 1.4, 2.7, 4.8, 10.5GHz. The polarisation has been measured with Effelsberg radiotelescope for 2.7, 4.8, 10.5GHz, while the 1.4 polarization is from NVSS (Cat. <VIII/65>) survey. Rotation Measures (RM) are presented for 143 radiosources.
Table 2 presents flux densities at 151, 327 and 408MHz and 1.4, 4.8 and 10.6GHz of B3-VLA sample and an updated list of the Optical Identifications of the sample.
74MHz flux densities are presented for 365 radiosources of the B3-VLA sample. Data were obtained as a by-product of the VLA A-array 74MHz survey of Tschager et al. (2003, Cat. <J/A+A/402/171>). These A-array data provide the first morphological information at this low frequency.
The orbit and physical parameters of the previously unsolved double-lined eclipsing binary V570 Per are derived using Asiago Echelle high-resolution and high S/N spectroscopy, and B, V photo-electric photometry. Effective temperatures, gravities, rotational velocities, and metallicities of both components are also obtained from atmospheric chi^2^ analysis. The observed properties of V570 Per components are compared to available families of stellar evolutionary tracks, in particular to BaSTI models computed on purpose for exactly the observed masses and varied chemical compositions.
We analyze light curves of the W UMa type eclipsing binary V781 Tauri from three epochs and radial velocity curves from two epochs simultaneously, including previously unpublished B and V data. The overall time span is from 1983 to 2000 and the solution is done coherently in time (not phase) with five light curves and two sets of primary and secondary velocity curves. Minor systematic differences among the individual light curves are not large enough to undermine the value of a coherent solution that represents 18 years of observations. Times of minima confirm a period of 0.34491d and the general solution finds a small period change, dP/P, of (5.08+/-04)*10^-11^ that represents recent behavior. The eclipse timings cover the last half-century and find dP/P about four times smaller, corresponding to a period change time scale, P/(dP/dt) of about 6 million years. The system is over-contact with a filling factor of 0.205. The solution produces a temperature difference of about 260K between the components, an inclination of 65.9{deg}, and a mass ratio M_2_/M_1_=2.47. Separate solutions of the several light curves that incorporate dark spots find parameters that differ little from curve to curve. Absolute masses, luminosities, radii and the distance are derived, with luminosities and distance based on star 1 being of type G0V. The orbital angular momentum is compared with those of other W UMa type binaries and is normal. The star to star mass flow that one can infer from dP/dt is opposite to that expected from TRO (Thermal Relaxation Oscillator) theory, but pertains to a time span that is very short compared to the time scale of TRO oscillations.
Cepheids, the principal distance indicators, point to the existence of two inner Galactic spiral arms in the immediate solar neighborhood (within 5kpc). However, the available Cepheids are clearly insufficient for a detailed study of the structure of these arms. Fortunately, southern-sky monitoring (the ASAS project) has led to the discovery of many new variable stars, more than one thousand of which have been identified as possible Cepheids. To improve the classification and to construct reliable light curves for new Cepheids, we have begun their regular photometric observations. Here, we present the first results: 1192 photoelectric BVIc observations were performed for 33 classicalCepheidswith the 76-cm telescope of the South-African Astronomical Observatory (SAAO, the South-African Republic) from December 2006 to January 2008.We provide tables of observations and V light and B-V and V-Ic color curves. The new observations together with ASAS-3 data have been used to improve the elements of the light variations.
In the Table 1 shown are the Heliocentric Julian Days at the start and at the end of the observation runs and the numbers of the observations for each color. Since the observations in 1991 have been published in Li et al. (1992IBVS.3802....1L), only those in 1992 and 1995 are listed in Table 2a and 2b for yellow and blue light respectively, where the Heliocentric Julian Days and the magnitude differences(the variable minus the comparison) are given. The normal points producing the light curves in Fig. 2 can found in Table 3 through 5.
We present ground-based photometry of the low-temperature contact binary BB Peg. We collected all the times of mid-eclipse available in the literature and combined them with those obtained in this study.
Accurate absolute properties are determined for the first time for the 3.15 day period eccentric eclipsing binary star FT Ori based on new absolute photometry, five differential light curves, and a radial velocity curve. The stars appear to be normal for their spectral types, A0+A2. The orbit is highly eccentric (e=0.409) and shows apsidal motion with a period of 536-years. The absolute properties and the degree of central mass concentration of the stars are consistent with current theoretical models at an age of 190Myr.
