- ID:
- ivo://CDS.VizieR/J/ApJ/742/123
- Title:
- Photometry and Velocity of LSPM J1112+7626
- Short Name:
- J/ApJ/742/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of eclipses in LSPM J1112+7626, which we find to be a moderately bright (I_C_=12.14+/-0.05) very low mass binary system with an orbital period of 41.03236+/-0.00002 days, and component masses M_1_=0.395+/-0.002M_{sun}_ and M_2_=0.275+/-0.001M_{sun}_ in an eccentric (e=0.239+/-0.002) orbit. A 65 day out-of-eclipse modulation of approximately 2% peak-to-peak amplitude is seen in I-band, which is probably due to rotational modulation of photospheric spots on one of the binary components. This paper presents the discovery and characterization of the object, including radial velocities sufficient to determine both component masses to better than 1% precision, and a photometric solution. We find that the sum of the component radii, which is much better determined than the individual radii, is inflated by 3.8^+0.9^_-0.5_% compared to the theoretical model predictions, depending on the age and metallicity assumed. These results demonstrate that the difficulties in reproducing observed M-dwarf eclipsing binary radii with theoretical models are not confined to systems with very short orbital periods. This object promises to be a fruitful testing ground for the hypothesized link between inflated radii in M-dwarfs and activity.
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- ID:
- ivo://CDS.VizieR/J/AJ/156/12
- Title:
- Photometry of {beta} Lyrae by the BRITE satellites
- Short Name:
- J/AJ/156/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric instabilities of {beta} Lyrae ({beta} Lyr) were observed in 2016 by two red-filter BRITE satellites over more than 10 revolutions of the binary, with ~100 minute sampling. Analysis of the time series shows that flares or fading events take place typically three to five times per binary orbit. The amplitudes of the disturbances (relative to the mean light curve, in units of the maximum out-of-eclipse light flux, f.u.) are characterized by a Gaussian distribution with {sigma}=0.0130+/-0.0004 f.u. Most of the disturbances appear to be random, with a tendency to remain for one or a few orbital revolutions, sometimes changing from brightening to fading or the reverse. Phases just preceding the center of the deeper eclipse showed the most scatter while phases around the secondary eclipse were the quietest. This implies that the invisible companion is the most likely source of the instabilities. Wavelet transform analysis showed the domination of the variability scales at phase intervals 0.05-0.3 (0.65-4 days), with the shorter (longer) scales dominating in numbers (variability power) in this range. The series can be well described as a stochastic Gaussian process with the signal at short timescales showing a slightly stronger correlation than red noise. The signal decorrelation timescale, {tau}=(0.068+/-0.018) in phase or (0.88+/-0.23) days, appears to follow the same dependence on the accretor mass as that observed for active galactic nucleus and quasi-stellar object masses five to nine orders of magnitude larger than the {beta} Lyr torus-hidden component.
- ID:
- ivo://CDS.VizieR/J/AJ/158/148
- Title:
- Photometry of beta Lyr by the BRITE satellites.II
- Short Name:
- J/AJ/158/148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of {beta} Lyr in four months of 2018 by three BRIght Target Explorer (BRITE) Constellation satellites, the red-filter BRITE-Toronto and BRITE-Heweliusz, and the blue-filter BRITE-Lem, permitted a first, limited look into the light-curve variability in two spectral bands. The variations were found to be well correlated outside the innermost phases of the primary eclipses with the blue variations appearing to have smaller amplitudes than the red; this reduction may reflect their presumed origin in the cooler, outer parts of the accretion disk. This result must be confirmed with more extensive material as the current conclusions are based on observations spanning slightly less than three orbital cycles of the binary. The assumption of an instrumental problem and the applied corrections made to explain the unexpectedly large amplitude of the red-filter light curve observed with the BRITE-Toronto satellite in 2016 are fully confirmed by the 2018 results.
454. Photometry of DE CVn
- ID:
- ivo://CDS.VizieR/J/A+A/466/1031
- Title:
- Photometry of DE CVn
- Short Name:
- J/A+A/466/1031
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Close white dwarf-red dwarf binaries must have gone through a common-envelope phase during their evolution. DE CVn is a detached white dwarf-red dwarf binary with a relatively short (~8.7h) orbital period. Its brightness and the presence of eclipses makes this system ideal for a more detailed study. From a study of photometric and spectroscopic observations of DE CVn we derive the system parameters that we discuss in the framework of common-envelope evolution.
- ID:
- ivo://CDS.VizieR/J/other/RMxAA/53.235
- Title:
- Photometry of 6 deep-contact W UMa
- Short Name:
- J/other/RMxAA/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric observations in Sloan g' and i' bands of W UMa binaries V0637 Peg, V0473 Cam, CSS J153314.8+560527, CSS J075258.0+382035, V0416 Gem and NSVS 6859986 are presented. Their periods are in the range of 0.26-0.43d. The light curve solutions revealed that the components of each target are almost equal in temperature. The stellar components are of G and K spectral types and undergo total eclipses. All targets have deep-contact configurations with fillout factor f>=0.5. NSVS 6859986 has one o f the biggest value determined until now, f=0.84. We studied the empirical dependencies of fillout factor on the stellar parameters (temperature, period, mass ratio, relative component radii, and luminosity ratio) for a sample of around thirty stars. They are consistent with the theoretical predictions but there are deviations from the common trends.
- ID:
- ivo://CDS.VizieR/J/A+A/573/A61
- Title:
- Photometry of new eclipsing CVs
- Short Name:
- J/A+A/573/A61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of eclipses and the first orbital period measurements for four cataclysmic variables, plus the first orbital period measurements for one known eclipsing and two magnetic systems. SDSS J093537.46+161950.8 exhibits 1-mag deep eclipses with a period of 92.245 min. SDSS J105754.25+275947.5 has short and deep eclipses and an orbital period of 90.44 min. Its light curve has no trace of a bright spot and its spectrum is dominated by the white dwarf component, suggesting a low mass accretion rate and a very low-mass and cool secondary star. CSS J132536+210037 shows 1-mag deep eclipses each separated by 89.821 min. SDSS J075653.11+085831.8 shows 2-mag deep eclipses on a period of 197.154 min. CSS J112634-100210 is an eclipsing dwarf nova identified in the Catalina Real Time Transit Survey, for which we measure a period of 111.523 min. SDSS J092122.84+203857.1 is a magnetic system with an orbital period of 84.240 min; its light curve is a textbook example of cyclotron beaming. A period of 158.72 min is found for the faint magnetic system SDSS J132411.57+032050.4, whose orbital light variations are reminiscent of AM Her. Improved orbital period measurements are also given for three known SDSS cataclysmic variables. We investigate the orbital period distribution and fraction of eclipsing systems within the SDSS sample and for all cataclysmic variables with a known orbital period, with the finding that the fraction of known CVs which are eclipsing is not strongly dependent on the orbital period.
- ID:
- ivo://CDS.VizieR/J/A+A/554/A25
- Title:
- Photometry of SDSS J152419.33+220920.0
- Short Name:
- J/A+A/554/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new photometry of the faint (g~19mag) and poorly studied cataclysmic variable SDSS J152419.33+220920.0, analyze its light curve and provide an accurate ephemeris for this system. Time-resolved CCD differential photometry was carried out using the 1.5m and 0.84m telescopes at the Observatorio Astronomico Nacional at San Pedro Martir. All observations were taken in white-light (no filter). This table contains the differential photometry for the system obtained during six nights (covering more than twenty primary eclipse cycles in more than three years). The reference for the photometry is SDSS J152415.99+220804.0, g=17.77 (marked as star C1 in the paper). The associated errors are 0.02mag outside eclipse. The information for each observation run is presented in Table 1 and the light-curves using this data are presented in Figure 4. Our light curve analysis shows that only two fundamental frequencies are present, corresponding to the orbital period and a modulation with twice this frequency. We determine the accurate ephemeris of the system to be HJD_eclipse_=2454967.6750(1)+0.06531866661(1)E. A double-hump orbital period modulation, a standing feature in several bounce-back systems at quiescence, is present at several epochs. However, we found no other evidence to support the hypothesis that this system belongs to the post-minimum orbital-period systems.
- ID:
- ivo://CDS.VizieR/J/A+A/544/L3
- Title:
- Photometry of the double eclipsing binary CzeV343
- Short Name:
- J/A+A/544/L3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of a possible new quadruple system composed of two unresolved eclipsing binaries (EBs), CzeV343 (V~13.5mag). We obtained photometric observations of CzeV343 that completely cover the two orbital periods and we successfully model the light curves as the sum of two detached EBs. The two orbital periods, 1.20937 and 0.80693-days, are within 0.1% of a 3:2 ratio. We speculate that this might be the result of Kozai cycles and tidal friction evolution of quadruple systems.
- ID:
- ivo://CDS.VizieR/J/AJ/158/186
- Title:
- Photometry of 12 totally eclipsing W UMa stars
- Short Name:
- J/AJ/158/186
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric observations of 12 totally eclipsing W UMa binaries (NSVS 3325547, V646 Lac, V1320 Cas, V539 Dra, V816 Cep, NSVS 9045055, V1115 Cas, V902 Cep, V596 Peg, NSVS 1768818, V619 Peg, and NSVS 3198272) are presented. We found that the longer (in phase units) the flat eclipses are, the smaller the mass ratios (or the reciprocal values) are. The mass ratios of five targets turned out close to the lower-mass ratio limit. We found that the periods of V1115 Cas and V646 Lac increase, while that of V596 Peg decreases. Masses, radii, and luminosities of the target components were calculated by the light-curve solutions and Gaia distances. In order to perform more reliable statistical analysis of the results we added to the sample of 12 targets from this paper another 29 totally eclipsing W UMa stars studied by us earlier. As a result we found the following trends: (a) the radius and luminosity of the target components increase with their mass but the dependencies are different from those of main-sequence (MS) stars; (b) the temperatures of stellar components whose masses are above 1 M_{sun}_ tend to be lower than those of the corresponding MS stars, while the temperatures of stellar components whose masses are below 1 M_{sun}_ tend to be higher than those of the corresponding MS stars; (c) there is no relationship between the fillout factor and mass ratio; and (d) 11 of the 41 targets are of A subtype, 24 are of W subtype, and 6 systems are with equal-temperature components.
- ID:
- ivo://CDS.VizieR/J/A+AS/124/291
- Title:
- Photometry of V700 Cyg and AW Vir
- Short Name:
- J/A+AS/124/291
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A photometric analysis of the W UMa systems V 700 Cyg and AW Vir, based on photoelectric B and V light curves, is presented. Since no spectroscopic mass-ratio is available, the q-search method was applied to find the preliminary range of the mass-ratio in order to search for the final solution. First, an unspotted solution was carried out by using the unperturbed parts of the light curves and applying the DC program of the WD code. The final spotted solution was made by adopting spot models for the two systems. In the case of V 700 Cyg, two cool spots were placed on the primary (more massive, larger and cooler) component to explain the O'Connell effect (MaxII fainter than MaxI) and a small deficit of light just before MaxI. In the case of AW Vir, one cool spot was placed on the primary component to explain the relatively large O'Connell effect. Both objects are W-type systems with partial eclipses; V 700 Cyg is fairly evolved while AW Vir is rather unevolved.
