- ID:
- ivo://CDS.VizieR/J/AJ/154/30
- Title:
- Photometric study of fourteen low-mass binaries
- Short Name:
- J/AJ/154/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New CCD photometric observations of fourteen short-period low-mass eclipsing binaries (LMBs) in the photometric filters I, R, and V were used for a light curve analysis. A discrepancy remains between observed radii and those derived from the theoretical modeling for LMBs, in general. Mass calibration of all observed LMBs was performed using only the photometric indices. The light curve modeling of these selected systems was completed, yielding the new derived masses and radii for both components. We compared these systems with the compilation of other known double-lined LMB systems with uncertainties of masses and radii less then 5%, which includes 66 components of binaries where both spectroscopy and photometry were combined together. All of our systems are circular short-period binaries, and for some of them, the photospheric spots were also used. A purely photometric study of the light curves without spectroscopy seems unable to achieve high enough precision and accuracy in the masses and radii to act as meaningful test of the M-R relation for low-mass stars.
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- ID:
- ivo://CDS.VizieR/J/AJ/152/75
- Title:
- Photometric survey of IC 2391, {eta} Cha, and USco
- Short Name:
- J/AJ/152/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The past two decades have seen a significant advancement in the detection, classification, and understanding of exoplanets and binaries. This is due, in large part, to the increase in use of small-aperture telescopes (<20cm) to survey large areas of the sky to milli-mag precision with rapid cadence. The vast majority of the planetary and binary systems studied to date consists of main-sequence or evolved objects, leading to a dearth of knowledge of properties at early times (<50Myr). Only a dozen binaries and one candidate transiting Hot Jupiter are known among pre-main-sequence objects, yet these are the systems that can provide the best constraints on stellar formation and planetary migration models. The deficiency in the number of well characterized systems is driven by the inherent and aperiodic variability found in pre-main-sequence objects, which can mask and mimic eclipse signals. Hence, a dramatic increase in the number of young systems with high-quality observations is highly desirable to guide further theoretical developments. We have recently completed a photometric survey of three nearby (<150pc) and young (<50Myr) moving groups with a small-aperture telescope. While our survey reached the requisite photometric precision, the temporal coverage was insufficient to detect Hot Jupiters. Nevertheless, we discovered 346 pre-main-sequence binary candidates, including 74 high-priority objects for further study.
- ID:
- ivo://CDS.VizieR/J/AJ/147/104
- Title:
- Photometry and velocities of 1SWASP J093010A and B
- Short Name:
- J/AJ/147/104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Among quadruples or higher multiplicity stars, only a few doubly eclipsing binary systems have been discovered. They are important targets for understanding the formation and evolution of multiple stellar systems because we can obtain accurate stellar parameters from photometric and spectroscopic studies. We present the observational results of this kind of rare object, 1SWASP J093010.78+533859.5, for which the doubly eclipsing feature had been detected previously from the SuperWASP photometric archive. Individual point-spread function photometry for two objects with a separation of about 1.9" was performed for the first time in this study. Our time-series photometric data confirms the finding of Lohr et al. that the bright object A is an Algol-type detached eclipsing binary and the fainter B is a W UMa-type contact eclipsing. Using high-resolution optical spectra, we obtained well-defined radial velocity variations of system A. Furthermore, stationary spectral lines were detected that must have originated from a further, previously unrecognized stellar component. It was confirmed by the third object contribution from the light-curve analysis. No spectral feature of system B was detected, probably due to motion blur by long exposure times. We obtained the binary parameters and the absolute dimensions of systems A and B from light-curve synthesis with and without radial velocities, respectively. The primary and secondary components of system A have a spectral type of K1 and K5 main sequences, respectively. Two components of system B have nearly the same type of K3 main sequence. Light variations for both binaries are satisfactorily modeled by using two-spot models with one starspot on each component. We estimated the distances to systems A and B individually. Two systems may have similar distances of about 70 pc and seem to be gravitationally bound with a separation of about 130 AU. In conclusion, we suggest that 1SWASP J093010.78+533859.5 is a quintuple stellar system with a hierarchical structure of a triple system A(ab)c and a binary system B(ab).
- 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/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/AJ/143/99
- Title:
- Photometry of W UMa eclipsing binaries
- Short Name:
- J/AJ/143/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on a BVRcIc survey of field W Ursae Majoris (UMa) binary stars and present accurate colors for 606 systems that have been observed on at least three photometric nights from a robotic observatory in southern Arizona. Comparison with earlier photometry for a subset of the systems shows good agreement. We investigate two independent methods of determining the interstellar reddening, although both have limitations that can render them less effective than desired. A subset of 101 systems shows good agreement between the two reddening methods.
- ID:
- ivo://CDS.VizieR/J/MNRAS/412/1787
- Title:
- Physical parameters of 62 eclipsing binaries
- Short Name:
- J/MNRAS/412/1787
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed light-curve analysis of publicly available V-band observations of 62 binary stars, mostly contact binaries, obtained by the All Sky Automated Survey (ASAS)-3 project between 2000 and 2009. Eclipsing binaries are important astronomical targets for determining the physical parameters of component stars from the geometry of their orbits. They provide an independent direct method of measuring the radii of stars. We improved the ASAS determined periods and ephemerides, and obtained the Fourier parameters from the phased light curves of these 62 stars.
- ID:
- ivo://CDS.VizieR/J/A+A/538/A112
- Title:
- Planetary transit candidates in CoRoT LRa01 field
- Short Name:
- J/A+A/538/A112
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CoRoT is a pioneering space mission whose primary goals are stellar seismology and extrasolar planets search. Its surveys of large stellar fields generate numerous planetary candidates whose lightcurves have transit-like features. An extensive analytical and observational follow-up effort is undertaken to classify these candidates.
- ID:
- ivo://CDS.VizieR/J/A+A/539/A14
- Title:
- Planetary transit candidates in CoRoT SRc01 field
- Short Name:
- J/A+A/539/A14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The space mission CoRoT is devoted to the analysis of stellar variability and the photometric detection of extrasolar planets. We present the list of planetary transit candidates detected in the first short run observed by CoRoT that targeted SRc01, towards the Galactic center in the direction of Aquila, which lasted from April to May 2007.
- ID:
- ivo://CDS.VizieR/J/ApJS/244/11
- Title:
- Planet candidates and EBs in K2 campaigns 0-8
- Short Name:
- J/ApJS/244/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We implement a search for exoplanets in campaigns zero through eight (C0-8) of the K2 extension of the Kepler spacecraft. We apply a modified version of the Quasi-periodic Automated Transit Search (QATS) planet search algorithm to K2 light curves produced by the EVEREST pipeline, carrying out the C0-8 search on 1.5x10^5^ target stars with magnitudes in the range of Kp=9-15. We detect 818 transiting planet candidates, of which 374 were undiscovered by prior searches, with {64, 15, 5, 2, 1} in {2, 3, 4, 5, 6}-planet multiplanet candidate systems, respectively. Of the new planets detected, 100 orbit M dwarfs, including one that is potentially rocky and in the habitable zone. A total of 154 of our candidates reciprocally transit with our solar system: they are geometrically aligned to see at least one solar system planet transit. We find candidates that display transit timing variations and dozens of candidates on both period extremes with single transits or ultrashort periods. We point to evidence that our candidates display similar patterns in frequency and size-period relation to confirmed planets, such as tentative evidence for the radius gap. Confirmation of these planet candidates with follow-up studies will increase the number of K2 planets by up to 50%, and characterization of their host stars will improve statistical studies of planet properties. Our sample includes many planets orbiting bright stars amenable for radial velocity follow-up and future characterization with JWST. We also list the 579 eclipsing binary systems detected as part of this search.
