- ID:
- ivo://CDS.VizieR/J/AJ/149/131
- Title:
- Parameters of galactic nearby main-sequence stars
- Short Name:
- J/AJ/149/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The mass-luminosity (M-L), mass-radius (M-R), and mass-effective temperature (M-T_eff_) diagrams for a subset of galactic nearby main-sequence stars with masses and radii accurate to {<=}3% and luminosities accurate to {<=}30% (268 stars) has led to a putative discovery. Four distinct mass domains have been identified, which we have tentatively associated with low, intermediate, high, and very high mass main-sequence stars, but which nevertheless are clearly separated by three distinct break points at 1.05, 2.4, and 7M_{sun}_ within the studied mass range of 0.38-32M_{sun}_. Further, a revised mass-luminosity relation (MLR) is found based on linear fits for each of the mass domains identified. The revised, mass-domain based MLRs, which are classical (L{propto}M^{alpha}^), are shown to be preferable to a single linear, quadratic, or cubic equation representing an alternative MLR. Stellar radius evolution within the main sequence for stars with M>1M_{sun}_ is clearly evident on the M-R diagram, but it is not clear on the M-T_eff_ diagram based on published temperatures. Effective temperatures can be calculated directly using the well known Stephan-Boltzmann law by employing the accurately known values of M and R with the newly defined MLRs. With the calculated temperatures, stellar temperature evolution within the main sequence for stars with M>1M_{sun}_ is clearly visible on the M-T_eff_ diagram. Our study asserts that it is now possible to compute the effective temperature of a main-sequence star with an accuracy of ~6%, as long as its observed radius error is adequately small (<1%) and its observed mass error is reasonably small (<6%).
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/154/105
- Title:
- Parameters of 529 Kepler eclipsing binaries
- Short Name:
- J/AJ/154/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present precise values of the eccentricity and periastron angle of 529 detached, eccentric, eclipsing stars from the Kepler Eclipsing Binary catalog that were determined by modeling their long cadence data. The temperatures and relative radii of their components as well as their mass ratios were calculated based on approximate values of the empirical relations of MS stars. Around one-third of the secondary components were revealed to be very late dwarfs, some of them possible brown dwarf candidates. Most of our targets fall below the envelope P(1-e^2^)^3/2^=5days. The (e,P) distribution of the known eccentric binaries exhibits a rough trend of increasing eccentricity with the period. The prolonged and continuous Kepler observations allowed us to identify 60 new highly eccentric targets with e>0.5.
- ID:
- ivo://CDS.VizieR/J/A+A/434/89
- Title:
- Parameters of LMC detached eclipsing binaries
- Short Name:
- J/A+A/434/89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As a result of a careful selection of eclipsing binaries in the Large Magellanic Cloud using the OGLE-II photometric database, we present a list of 98 systems that are suitable targets for spectroscopic observations that would lead to the accurate determination of the distance to the LMC. For these systems we derive preliminary parameters combining the OGLE-II data with the photometry of MACHO and EROS surveys. In the selected sample, 58 stars have eccentric orbits. Among these stars we found fourteen systems showing apsidal motion. The data do not cover the whole apsidal motion cycle, but follow-up observations will allow detailed studies of these interesting objects.
- ID:
- ivo://CDS.VizieR/J/A+A/549/A86
- Title:
- Period change for 143 SuperWASP eclipsing binaries
- Short Name:
- J/A+A/549/A86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Building on previous work, a new search of the SuperWASP archive was carried out to identify eclipsing binary systems near the short-period limit. 143 candidate objects were detected with orbital periods between 16000 and 20000s, of which 97 are new discoveries. Period changes significant at 1{sigma} or more were detected in 74 of these objects, and in 38 the changes were significant at 3{sigma} or more. The significant period changes observed followed an approximately normal distribution with a half-width at half-maximum of ~0.1s/yr. There was no apparent relationship between period length and magnitude or direction of period change. Amongst several interesting individual objects studied, 1SWASP J093010.78+533859.5 is presented as a new doubly eclipsing quadruple system, consisting of a contact binary with a 19674.575s period and an Algol-type binary with a 112799.109s period, separated by 66.1AU, being the sixth known system of this type.
- ID:
- ivo://CDS.VizieR/J/A+A/578/A136
- Title:
- Period changes in SuperWASP eclipsing binaries
- Short Name:
- J/A+A/578/A136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Orbital period changes of binary stars may be caused by the presence of a third massive body in the system. Here we have searched the archive of the Wide Angle Search for Planets (SuperWASP) project for evidence of period variations in 13927 eclipsing binary candidates. Sinusoidal period changes, strongly suggestive of third bodies, were detected in 2% of cases; however, linear period changes were observed in a further 22% of systems. We argue on distributional grounds that the majority of these apparently linear changes are likely to reflect longer-term sinusoidal period variations caused by third bodies, and thus estimate a higher-order multiplicity fraction of 24% for SuperWASP binaries, in good agreement with other recent figures for the fraction of triple systems amongst binary stars in general.
- ID:
- ivo://CDS.VizieR/J/MNRAS/405/1930
- Title:
- Period changes of EA-, EB- and EW-types binaries
- Short Name:
- J/MNRAS/405/1930
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cyclic period changes are a fairly common phenomenon in close binary systems and are usually explained as being caused either by the magnetic activity of one or both components or by the light travel time effect (LTTE) of a third body. We searched the orbital period changes in 182 EA-type (including the 101 Algol systems used by Hall, 1989, Space Sci. Rev., 50, 219), 43 EB-type and 53 EW-type binaries with known mass ratio and spectral type of the secondary component. We reproduced and improved the diagram in Hall according to the new collected data.
- ID:
- ivo://CDS.VizieR/J/AcA/56/253
- Title:
- Period changes of OGLE contact binaries
- Short Name:
- J/AcA/56/253
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Presented are results of determination of secular period changes for 569 contact binaries from the OGLE database with periods shorter than about one day and observations spanning 14 observing seasons. The statistically significant rates of secular changes found for 134 stars are distributed nearly symmetrically around zero with a half-width of the distribution equal to about 3.5x10^-7^d/yr. The remaining rates are confined within the error distribution with dispersion about 2.3x10^-7^d/yr. The largest rates of period change that have been found are of the order of 5x10^-6^d/yr.
- ID:
- ivo://CDS.VizieR/J/A+A/602/A117
- Title:
- Periods of 2290 CoRoT binaries
- Short Name:
- J/A+A/602/A117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CoRoT mission during its flight-phase 2007-2012 delivered the light-curves for over 2000 eclipsing binaries. Data from the Kepler mission have proven the existence of several transiting circumbinary planets. Albeit light-curves from CoRoT have typically lower precision and shorter coverage, CoRoT's number of targets is similar to Kepler, and some of the known circumbinary planets could potentially be detected in CoRoT data as well. The aim of this work has been a revision of the entire CoRoT data-set for the presence of circumbinary planets, and the derivation of limits to the abundances of such planets. We developed a code which removes the light curve of the eclipsing binaries and searches for quasi-periodic transit-like features in a light curve after removal of binary eclipses and instrumental features. The code needs little information on the sample systems and can be used for other space missions as well, like Kepler, K2, TESS and PLATO. The code is broad in the requirements leading to detections, but was tuned to deliver an amount of detections that is manageable in a subsequent, mainly visual, revision about their nature. In the CoRoT sample we identified three planet candidates whose transits would have arisen from a single pass across the central binary. No candidates remained however with transit events from multiple planetary orbits. We calculated the upper limits for the number of Jupiter, Saturn and Neptune sized planets in co-planar orbits for different orbital period ranges. We found that there are much less giant planets in short-periodic orbits around close binary systems than around single stars.
- ID:
- ivo://CDS.VizieR/J/A+A/566/A128
- Title:
- Period variations in SuperWASP PCEB
- Short Name:
- J/A+A/566/A128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Period or amplitude variations in eclipsing binaries may reveal the presence of additional massive bodies in the system, such as circumbinary planets. Here, we have studied twelve previously-known eclipsing post-common-envelope binaries for evidence of such light curve variations, on the basis of multi-year observations in the SuperWASP archive. The results for HW Vir provided strong evidence for period changes consistent with those measured by previous studies, and help support a two-planet model for the system. ASAS J102322-3737.0 exhibited plausible evidence for a period increase not previously suggested; while NY Vir, QS Vir and NSVS 14256825 afforded less significant support for period change, providing some confirmation to earlier claims. In other cases, period change was not convincingly observed; for AA Dor and NSVS 07826147, previous findings of constant period were confirmed. This study allows us to present hundreds of new primary eclipse timings for these systems, and further demonstrates the value of wide-field high-cadence surveys like SuperWASP for the investigation of variable stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/901/169
- Title:
- Photometric obs. & LAMOST sp. of 4 W UMa binaries
- Short Name:
- J/ApJ/901/169
- Date:
- 22 Feb 2022 00:36:07
- Publisher:
- CDS
- Description:
- We present new photometric data and LAMOST spectra for the W UMa binaries UV Lyn, V781 Tau, NSVS 4484038, and 2MASS J15471055+5302107. The orbital and starspot parameters are obtained using the Wilson-Devinney program. Comparing the starspot parameters at different times, there are magnetic activities in these four binaries. The orbital period of UV Lyn is increasing at a rate of dP/dt=+8.9(5)x10^-8^d/yr, which maybe due to mass transfer from the less massive component to the more massive component (dM1/dt=-6.4x10^-8^M_{sun}_/yr). The period variation of 2MASSJ15471055+5302107 is also increasing at a rate of 6.0(4)x10^-7^d/yr, which can be explained by mass transfer from the less massive component to the more massive component (dM1/dt=-2.8x10^-7^M_{sun}_/yr). The period variation of V781 Tau presents the downward parabola superimposed the cyclic oscillation. The period of V781 Tau is decreasing (dP/dt=-3.2(4)x10^-8^d/yr), which can be explained by mass transfer from the more massive component to the less massive component (dM2/dt=-2.2x10^-8^M_{sun}_/yr). The cyclic oscillation may be due to the magnetic activity with a period of 30.8(5)yr rather than a third body. The period variation of NSVS4484038 also shows the cyclic oscillation, which could be explained by the magnetic activity with 10.8(1)yr or a black hole candidate. Interestingly, there is a depth variation between the light minimum times of NSVS 4484038, which may also be caused by stellar magnetic activity.
