- ID:
- ivo://CDS.VizieR/J/AJ/151/26
- Title:
- Spectroscopy of five {gamma} Dor variables
- Short Name:
- J/AJ/151/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have determined the spectroscopic orbits of five {gamma} Dor variables, HD776, HD6568, HD17310, HD19684, and HD62196. Their orbital periods range from 27.8 to 1163days and their eccentricities from 0.01 to 0.65. Of the five systems, only HD19684 shows lines of its binary companion, but those lines are always so weak and blended with the lines of the primary that we were unable to measure them satisfactorily. The velocity residuals of the orbital fits were searched for periodicities associated with pulsation. No clear, convincing case for velocity periodicities in the residuals was found in four of the five stars. However, for HD17310 we identified a period of 2.13434days, a value in agreement with the largest amplitude period previously found photometrically for that star. The velocity residuals of HD62196 have a long-term trend suggesting that it is a triple system.
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- ID:
- ivo://CDS.VizieR/J/A+A/649/A64
- Title:
- TESS time of eclipse of 15 eclipsing binaries
- Short Name:
- J/A+A/649/A64
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The change in the argument of periastron of eclipsing binaries, that is, the apsidal motion caused by classical and relativistic effects, can be measured from variations in the difference between the time of minimum light of the primary and secondary eclipses. Poor apsidal motion rate determinations and large uncertainties in the classical term have hampered previous attempts to determine the general relativistic term with sufficient precision to test general relativity predictions. As a product of the TESS mission, thousands of high-precision light curves from eclipsing binaries are now available. Using a selection of suitable well-studied eccentric eclipsing binary systems, we aim to determine their apsidal motion rates and place constraints on key gravitational parameters. We compute the time of minimum light from the TESS light curves of 15 eclipsing binaries with precise absolute parameters and with an expected general relativistic contribution to the total apsidal motion rate of greater than 60%. We use the changing primary and secondary eclipse timing differences over time to compute the apsidal motion rate, when possible, or the difference between the linear periods as computed from primary and secondary eclipses. For a greater time baseline we carefully combine the high-precision TESS timings with archival reliable timings. We determine the apsidal motion rate of 9 eclipsing binaries, 5 of which are reported for the first time. From these, we are able to measure the general relativistic apsidal motion rate of 6 systems with sufficient precision to test general relativity for the first time using this method. This test explores a regime of gravitational forces and potentials that had not been probed before. We find perfect agreement with theoretical predictions, and we are able to set stringent constraints on two parameters of the parametrised post-Newtonian formalism.
- ID:
- ivo://CDS.VizieR/V/39
- Title:
- 4th Catalog of Orbits of Visual Binaries
- Short Name:
- V/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Finsen-Worley Catalog (1970), supplemented by all subsequently published orbits known to Worley and Heintz as of 1 July 1982 formed the basis for the present compilation. Practically all stars having visual orbits were reobserved in the preceding decade, often repeatedly either with micrometers or with speckle interferometers. Astrometric solutions are included but only if they were judged to be relatively certain. Orbits with period greater than 4000 years and hyperbolic orbits were rejected as being unreliable. The catalog contains 928 orbits of 847 systems (counting triples as two systems). There are 23 orbits of unresolved systems. The catalog contains for each system the names of the star and the components involved, the 1900 position, the ADS number, the magnitude and spectral type for each component, the orbital elements, the equinox of the node, the quality of the orbit, the date of the last observation, the inclusive dates for which an ephemeris is given by the author, the computer of the orbit, and a reference.
- ID:
- ivo://CDS.VizieR/J/A+A/369/249
- Title:
- T Tauri binary systems orbital motion
- Short Name:
- J/A+A/369/249
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using speckle-interferometry we have carried out repeated measurements of relative positions for the components of 34 T Tauri binary systems. The projected separation of these components is low enough that orbital motion is expected to be observable within a few years. In most cases orbital motion has indeed been detected. The observational data is discussed in a manner similar to Ghez et al. (1995AJ....110..753G). However, we extend their study to a larger number of objects and a much longer timespan. The database presented in this paper is valuable for future visual orbit determinations. It will yield empirical masses for T Tauri stars that now are only poorly known. The available data is however not sufficient to do this at the present time. Instead, we use short series of orbital data and statistical distributions of orbital parameters to derive an average system mass that is independent of theoretical assumptions about the physics of PMS stars. For our sample this mass is and thus in the order of magnitude one expects for the mass sum of two T Tauri stars. It is also comparable to mass estimates obtained for the same systems using theoretical PMS evolutionary models.
- ID:
- ivo://CDS.VizieR/J/A+A/341/121
- Title:
- Visual binary orbits and masses
- Short Name:
- J/A+A/341/121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The paper gives orbits and masses for some 200 nearby visual binaries, as derived from combining ground-based and Hipparcos data. Table 6 gives identifications and notes, and points to the detailed data in Table 1 (short-P systems with mass-ratio from the Hipparcos observations), Table 3 (mass-uncertainty below 10%) or Table 4 (mass-uncertainty above 10%).
- ID:
- ivo://CDS.VizieR/J/A+AS/132/253
- Title:
- 9 visual double stars orbital elements
- Short Name:
- J/A+AS/132/253
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Orbital elements and ephemerides for 9 visual double stars are given.
- ID:
- ivo://CDS.VizieR/J/AJ/148/38
- Title:
- WIYN open cluster study. LX. RV survey of NGC 6819
- Short Name:
- J/AJ/148/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the current state of the WOCS radial-velocity (RV) survey for the rich open cluster NGC 6819 (2.5Gyr) including 93 spectroscopic binary orbits with periods ranging from 1.5 to 8000days. These results are the product of our ongoing RV survey of NGC 6819 using the Hydra Multi-Object Spectrograph on the WIYN 3.5m telescope. We also include a detailed analysis of multiple prior sets of optical photometry for NGC 6819. Within a 1{deg} field of view, our stellar sample includes the giant branch, the red clump, and blue straggler candidates, and extends to almost 2 mag below the main sequence (MS) turnoff. For each star observed in our survey we present all RV measurements, the average RV, and velocity variability information. Additionally, we discuss notable binaries from our sample, including eclipsing binaries (WOCS 23009, WOCS 24009, and WOCS 40007), stars noted in Kepler asteroseismology studies (WOCS 4008, WOCS 7009, and WOCS 8007), and potential descendants of past blue stragglers (WOCS 1006 and WOCS 6002). We find the incompleteness-corrected binary fraction for all MS binaries with periods less than 10^4^days to be 22%+/-3% and a tidal circularization period of 6.2^+1.1^_-1.1_days for NGC 6819.
- ID:
- ivo://CDS.VizieR/J/MNRAS/373/1483
- Title:
- W UMa type and CAB stars dynamical evolution
- Short Name:
- J/MNRAS/373/1483
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Orbital angular momentum (OAM, Jo), systemic mass (M) and orbital period (P) distributions of chromospherically active binaries (CAB) and W Ursae Majoris (W UMa) systems were investigated. The diagrams of and logJo-logP, logM-logP and logJo-logM were formed from 119 CAB and 102 W UMa stars. The log Jo-logM diagram is found to be most meaningful in demonstrating dynamical evolution of binary star orbits. A slightly curved borderline (contact border) separating the detached and the contact systems was discovered on the logJo-logM diagram. Since the orbital size (a) and period (P) of binaries are determined by their current Jo, M and mass ratio, q, the rates of OAM loss (dlogJo/dt) and mass loss (dlogM/dt) are primary parameters to determine the direction and the speed of the dynamical evolution. A detached system becomes a contact system if its own dynamical evolution enables it to pass the contact border on the logJo-logM diagram. The evolution of q for a mass-losing detached system is unknown unless the mass-loss rate for each component is known. Assuming q is constant in the first approximation and using the mean decreasing rates of Jo and M from the kinematical ages of CAB stars, it has been predicted that 11, 23 and 39 per cent of current CAB stars would transform to W UMa systems if their nuclear evolution permits them to live 2, 4 and 6Gyr, respectively.
