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- ID:
- ivo://CDS.VizieR/J/A+A/454/855
- Title:
- Geneva photometry of W Cru
- Short Name:
- J/A+A/454/855
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Light curves of the long-period Algols are known for their complex (asymmetry in the eclipse, light variations outside the eclipse, changes from cycle-to-cycle), but their interpretation is not possible in the standard model of binary stars. We determined that complex structures present in these active Algol systems could be studied with the eclipse-mapping method that was successfully applied to the new 7-color photometric observations in the Geneva system of W Cru, belonging to the isolated group of these active Algols. Several cycles of this long-period (198.5-days) eclipsing binary were covered by observations. We used a modified Rutten's approach to the eclipse-mapping. The optimization of the system's parameters and the recovery of the disk intensity distribution are performed using a genetic algorithm (GA). The finding of a primary (hot) component is hidden in thick accretion disk confirms previous solutions. The mass of the primary component, M_1_=8.2M_{sun}_, indicates that it is a mid-B type star. The mass-losing component fills its critical lobe, which, for the system's parameters, means it is a G-type supergiant with a mass M_2_=1.6M_{sun}_. The disk is very extended geometrically, and its outer radius is about 80% of the primary's critical lobe. A reconstructed image reveals the rather clumpy and nonuniform brightness distribution of an accretion disk rim in this system that is seen almost edge-on. This clumpiness accounts for light curve distortions and asymmetries, as well as for secular changes.
- ID:
- ivo://CDS.VizieR/J/A+A/563/A21
- Title:
- GJ 1214 Trappist and Spitzer light curves
- Short Name:
- J/A+A/563/A21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-precision eclipse spectrophotometry of transiting terrestrial exoplanets represents a promising path for the first atmospheric characterizations of habitable worlds and the search for life outside our solar system. The detection of terrestrial planets transiting nearby late-type M-dwarfs could make this approach applicable within the next decade, with soon-to-come general facilities. In this context, we previously identified GJ 1214 as a high-priority target for a transit search, as the transit probability of a habitable planet orbiting this nearby M4.5 dwarf would be significantly enhanced by the transiting nature of GJ 1214 b, the super-Earth already known to orbit the star. Based on this observation, we have set up an ambitious high-precision photometric monitoring of GJ 1214 with the Spitzer Space Telescope to probe the inner part of its habitable zone in search of a transiting planet as small as Mars. We present here the results of this transit search.
- ID:
- ivo://CDS.VizieR/J/other/NewA/17.296
- Title:
- GO Cyg BV light curves
- Short Name:
- J/other/NewA/17.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this study, we present long term photometric variations of the close binary system GO Cyg. Modelling of the system shows that the primary is filling Roche lobe and the secondary of the system is almost filling its Roche lobe. The physical parameters of the system are M_1_=3.0+/-0.2M_{sun}_, M_2_=1.3+/-0.1M_{sun}_, R_1_=2.50+/-0.12R_{sun}_, R_2_=1.75+/-0.09R_{sun}_, L_1_=64+/-9L_{sun}_, L_2_=4.9+/-0.7L_{sun}_, and a=5.5+/-0.3R_{sun}_. Our results show that GO Cyg is the most massive system near contact binary (NCB). Analysis of times of the minima shows a sinusoidal variation with a period of 92.3+/-0.5-years due to a third body whose mass is less than 2.3M_{sun}_. Finally a period variation rate of -1.4x10^-9^d/yr has been determined using all available light curves.
- ID:
- ivo://CDS.VizieR/J/A+A/455/247
- Title:
- Grid of close binaries experiencing mass exchange
- Short Name:
- J/A+A/455/247
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To simulate the population of the primordial blue stragglers in old open clusters, a grid of close binaries experiencing mass exchange is needed. To this aim, various combinations that can trigger mass exchange for the donor masses of 0.1M_{sun}_ to 2.0M_{sun}_ are calculated with a fine grid in parameters. The mass range of the accretor is from 0.1M_{sun}_ to the mass of the corresponding donor. The mass intervals of the donors and the accretors are all 0.1M_{sun}_. To cover all possible cases of close binaries, the orbit separation ranges from 1.0 to 50.0R_{sun}_ with a grid interval of 1.0R_{sun}_. Following the numerical scheme described above, a grid for six ages from 1.0Gyr to 6.0Gyr is obtained. In this table, mass, effective temperature, luminosity, gravity, Hydrogen abundance in the core, Helium abundance in the core, B magnitude, V magnitude, B-V color, mass ratio, orbital separation and period of the close binaries experiencing mass exchange are given.
- ID:
- ivo://CDS.VizieR/J/A+A/395/587
- Title:
- GR Tau BV light curves
- Short Name:
- J/A+A/395/587
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric observations of the eclipsing binary GR Tau made in 1985, 1993, 1998, 2000 and 2001.
- ID:
- ivo://CDS.VizieR/J/AJ/140/1150
- Title:
- GSC 3355-0394 BVRI differential photometry
- Short Name:
- J/AJ/140/1150
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- GSC 3355 0394 has an EB-type light curve, which is dominated by hot and cool spot activities. It displays night-to-night variations in light-curve shapes. The period study yields six new times of minimum light and the first precision ephemeris, HJD TminI=2454408.9547+/-0.0017+0.4621603+/-.0000008d*E. VRcIc standard magnitudes are presented. BVRI Wilson synthetic light-curve solutions are calculated for both a Mode 4 (V1010 Oph-type, semidetached, more massive component filling its Roche lobe) configuration and a Mode 3, contact configuration (fill-out 100% or critical contact). The critical contact is the lowest residual solution. Four major spot regions are needed to model this binary, at least one is evidently a stream spot.
- ID:
- ivo://CDS.VizieR/J/A+A/590/A45
- Title:
- GU Mon BV light curves
- Short Name:
- J/A+A/590/A45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive analysis, including B and V light curves and 11 high-resolution spectra, to verify the orbital period and determine parameters. The spectroscopic and photometric analyses agree on a period of 0.896640+/-0.000007d. We determine a mass of 9.0+/-0.6M_{sun}_ for each component and temperatures of 28000+/-2000K. Both values are consistent with the spectral type B1V. The two stars are overfilling their respective Roche lobes, sharing a common envelope, and therefore the orbit is synchronised and circularised. Thetwo stars are in a very advanced stage of interaction, with their extreme physical similarity likely due to the common envelope. The expected evolution of such a system will very probably lead to a merger while still on the main sequence.
- ID:
- ivo://CDS.VizieR/J/ApJ/726/L19
- Title:
- Gunn r photometry of WASP-30
- Short Name:
- J/ApJ/726/L19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a 61-Jupiter-mass brown dwarf (BD), which transits its F8V host star, WASP-30, every 4.16 days. From a range of age indicators we estimate the system age to be 1-2Gyr. We derive a radius (0.89+/-0.02R_Jup_) for the companion that is consistent with that predicted (0.914R_Jup_) by a model of a 1Gyr old, non-irradiated BD with a dusty atmosphere. The location of WASP-30b in the minimum of the mass-radius relation is consistent with the quantitative prediction of Chabrier & Baraffe, thus confirming the theory.
- ID:
- ivo://CDS.VizieR/J/AJ/135/1757
- Title:
- GX Gem radial velocities and light curves
- Short Name:
- J/AJ/135/1757
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 12,155 new differential photometric observations in the V filter made with the Undergraduate Research Studies in Astronomy and NF\Observatory WebScopes, as well as 33 radial velocities from spectroscopic observations of the detached, 4.04 day double-lined eclipsing binary star GX Gem. Absolute dimensions of the components are determined from these new, and also from previously published, data with high precision (less than 0.7% in the masses and radii) for the purpose of testing various aspects of theoretical modeling. We obtain 1.488+/-0.011 solar masses and 2.327+/-0.012 solar radii for the primary, and 1.467+/-0.010 solar masses and 2.238+/-0.012 solar radii for the secondary. The effective temperatures and interstellar reddening of the stars are accurately determined from the spectra, uvby{beta}, and UBV photometry: 6195+/-100K for the primary, 6165+/-100K for the secondary, corresponding to spectral types of F7 and F7 V, and 0.068mag for the color excess E(b-y). Spectral line widths give rotational velocities that are synchronous with the mean orbital motion in a circular orbit.
