- ID:
- ivo://CDS.VizieR/J/A+A/633/A37
- Title:
- RXJ1604.3-2130A griz and JHK light curves
- Short Name:
- J/A+A/633/A37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- RX J1604.3-2130A is a young, dipper-type, variable star in the Upper Scorpius association, suspected to have an inclined inner disk with respect to its face-on outer disk. We study the eclipses to constrain the inner disk properties. We use time-resolved photometry from the Rapid Eye Mount telescope and Kepler 2 data to study the multi-wavelength variability, and archival optical and IR data to track accretion, rotation, and changes in disk structure. The observations reveal details of the structure and matter transport through the inner disk. The eclipses show 5d quasi-periodicity, with the phase drifting in time and some periods showing increased/decreased eclipse depth and frequency. Dips are consistent with extinction by slightly processed dust grains in an inclined, irregularly-shaped inner disk locked to the star through two relatively stable accretion structures. The grains are located near the dust sublimation radius (~0.09au) at the corotation radius, and can explain the shadows observed in the outer disk. The total mass (gas and dust) required to produce the eclipses and shadows is a few % of a Ceres mass. Such amount of mass is accreted/replenished by accretion in days to weeks, which explains the variability from period to period. Spitzer and WISE variability reveal variations in the dust content in the innermost disk on a few years timescale, which is consistent with small imbalances (compared to the stellar accretion rate) in the matter transport from the outer to the inner disk. A decrease in the accretion rate is observed at the times of less eclipsing variability and low mid-IR fluxes, confirming this picture. The vsini=16km/s confirms that the star cannot be aligned with the outer disk, but is likely close to equator-on and to be aligned with the inner disk. This anomalous orientation is a challenge for standard theories of protoplanetary disk formation.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/527/A143
- Title:
- RX J105453.3+552102 cluster SDSS photometry
- Short Name:
- J/A+A/527/A143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The most accepted scenario for the origin of fossil groups is that they are galaxy associations in which the merging rate was fast and efficient. These systems have assembled half of their mass at early epoch of the Universe, subsequently growing by minor mergers, and therefore could contain a fossil record of the galaxy structure formation. We have started an observational project in order to characterize a large sample of fossil groups. In this paper we present the analysis of the fossil system RX J105453.3+552102.
3163. RY Sct UBVR photometry
- ID:
- ivo://CDS.VizieR/J/A+A/374/638
- Title:
- RY Sct UBVR photometry
- Short Name:
- J/A+A/374/638
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The present study deals with the problem of the estimation of the orbital and physical parameters for the EB-type eclipsing binary RY Sct, based on the interpretation of new photometric U B V R observations. The light curves obtained at the Maidanak Observatory during 1979-94 show a slight asymmetry around the secondary minima and a small difference in the height of the successive maxima. The light curves are analysed in the framework of the Roche computer model (Djurasevic, 1992Ap&SS.196..241D) by applying the inverse-problem method (Djurasevic, 1992Ap&SS.197...17D) based on Marquardt's (1963, J. Soc. Ind. Appl. Math. 11(2), 431) algorithm. The analysis shows that RY Sct system is in an overcontact configuration (f_over_~33%) with q=m_2_/m_1_=m_cool_/m_hot_=3.3 and i~84.3{deg}, generating total-annular eclipses. The basic parameters of the system and of the active region are estimated for all individual U, B, V and R light curves. Our results suggested a mass exchange between the components and mass loss through the outer Lagrangian point L_3_. This could be taken as a possible mechanism in the formation of the circumstellar envelope of toroidal form lying in the orbital plane of the system.
3164. RY Tau in 1996
- ID:
- ivo://CDS.VizieR/J/A+A/341/553
- Title:
- RY Tau in 1996
- Short Name:
- J/A+A/341/553
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The T Tauri star RY Tau has increased its brightness from V=10.6mag to V=9.6mag in October-November 1996. By February-March 1997, the star has faded again to V=10.8mag. High-resolution echelle spectra of RY Tau were obtained wit h the SOFIN spectrograph at the Nordic Optical Telescope (La Palma, Spain) at lo w and high brightness levels of the star. No significant changes in the photosph eric lines, which are sensitive to temperature and gravity, were noticed. The spectral type of RY Tau is defined as G1-2IV, which in combination with photomet ric data implies A_V_=1.0-1.3mag. Polarimetric patrol of RY Tau during the fadin g of the star showed an increase of its intrinsic polarization from 0.5-1.0% at high brightness to about 2% at low brightness in the V, R and I bands. The flux radiated in H{alpha} and the IR Ca II emission lines remained about the same, in spite of the one magnitude difference in the continuum flux. These results indicate that variable obscuration of the star by circumstellar dust clo uds was responsible for the brightness change of RY Tau, and that the emission l ine source is mostly outside of the obscured region.
3165. RZ Dra
- ID:
- ivo://CDS.VizieR/J/A+A/285/459
- Title:
- RZ Dra
- Short Name:
- J/A+A/285/459
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
3166. RZ Dra BVR light curves
- ID:
- ivo://CDS.VizieR/J/AJ/140/1687
- Title:
- RZ Dra BVR light curves
- Short Name:
- J/AJ/140/1687
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new multicolor photometry for RZ Draconis, observed in 2009 at the Xinglong Station of the National Astronomical Observatories of China. By using the updated version of the Wilson-Devinney Code, the photometric-spectroscopic elements were deduced from new photometric observations and published radial velocity data.
3167. RZ Tau UBVR photometry
- ID:
- ivo://CDS.VizieR/J/A+A/343/894
- Title:
- RZ Tau UBVR photometry
- Short Name:
- J/A+A/343/894
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJ/787/110
- Title:
- SAGA: Stromgren survey of seismic KIC stars
- Short Name:
- J/ApJ/787/110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Asteroseismology has the capability of precisely determining stellar properties that would otherwise be inaccessible, such as radii, masses, and thus ages of stars. When coupling this information with classical determinations of stellar parameters, such as metallicities, effective temperatures, and angular diameters, powerful new diagnostics for Galactic studies can be obtained. The ongoing Stromgren survey for Asteroseismology and Galactic Archaeology (SAGA) has the goal of transforming the Kepler field into a new benchmark for Galactic studies, similar to the solar neighborhood. Here we present the first results from a stripe centered at a Galactic longitude of 74{deg} and covering latitude from about 8{deg} to 20{deg}, which includes almost 1000 K giants with seismic information and the benchmark open cluster NGC 6819. We describe the coupling of classical and seismic parameters, the accuracy as well as the caveats of the derived effective temperatures, metallicities, distances, surface gravities, masses, and radii. Confidence in the achieved precision is corroborated by the detection of the first and secondary clumps in a population of field stars with a ratio of 2 to 1 and by the negligible scatter in the seismic distances among NGC 6819 member stars. An assessment of the reliability of stellar parameters in the Kepler Input Catalog is also performed, and the impact of our results for population studies in the Milky Way is discussed, along with the importance of an all-sky Stromgren survey.
- ID:
- ivo://CDS.VizieR/J/ApJ/778/15
- Title:
- SAGE-SMC III. Young stellar objects
- Short Name:
- J/ApJ/778/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Spitzer Space Telescope Legacy Program SAGE-SMC allows global studies of resolved stellar populations in the SMC in a different environment than our Galaxy. Using the SAGE-SMC IRAC (3.6-8.0{mu}m) and MIPS (24 and 70{mu}m) catalogs and images combined with near-infrared (JHK_s_) and optical (UBVI) data, we identified a population of ~1000 intermediate - to high-mass young stellar objects (YSOs) in the SMC (three times more than previously known). Our method of identifying YSO candidates builds on the method developed for the Large Magellanic Cloud by Whitney et al. (2008, J/AJ/136/18) with improvements based on what we learned from our subsequent studies and techniques described in the literature. We perform (1) color-magnitude cuts based on five color-magnitude diagrams (CMDs), (2) visual inspection of multi-wavelength images, and (3) spectral energy distribution (SED) fitting with YSO models. For each YSO candidate, we use its photometry to calculate a measure of our confidence that the source is not a non-YSO contaminant, but rather a true YSO, based on the source's location in the color-magnitude space with respect to non-YSOs. We use this CMD score and the SED fitting results to define two classes of sources: high-reliability YSO candidates and possible YSO candidates. We found that, due to polycyclic aromatic hydrocarbon emission, about half of our sources have [3.6]-[4.5] and [4.5]-[5.8] colors not predicted by previous YSO models. The YSO candidates are spatially correlated with gas tracers.
- ID:
- ivo://CDS.VizieR/II/229
- Title:
- Sakurai's object (V4334 Sgr) in 1996-1998
- Short Name:
- II/229
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The photometric UBV observations of V4334 Sgr during 1996-1998 are presented. V4334 Sgr is the nucleus of a planetary nebula during the last helium flash of the shell source and it entered the R CrB phase.
