- ID:
- ivo://CDS.VizieR/J/ApJS/119/141
- Title:
- Oxygen-rich dust shells IR spectral classification
- Short Name:
- J/ApJS/119/141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents infrared spectral classifications for a flux-limited sample of 635 optically identified oxygen-rich variables including supergiants and sources on the asymptotic giant branch (AGB). Several classes of spectra from oxygen-rich dust exist, and these can be arranged in a smoothly varying sequence of spectral shapes known as the silicate dust sequence. Classification based on this sequence reveals several dependencies of the dust emission on the properties of the central star. Nearly all S stars show broad emission features from alumina dust, while most of the supergiants exhibit classic features from amorphous silicate dust. Mira variables with symmetric light curves generally show broad alumina emission, while those with more asymmetric light curves show classic silicate emission. These differences may arise from differences in the photospheric C/O ratio.
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- ID:
- ivo://CDS.VizieR/J/PAZh/27/132
- Title:
- Parameters of RR Lyrae Type Variables
- Short Name:
- J/PAZh/27/132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The method of statistical parallaxes is applied to a sample of 262 Rrab RR Lyr type variables with published photoelectric photometry, radial velocities, abundances and with known absolute proper motions. The proper motions are adopted from the Hipparcos, PPM, NPM1, and the Four-Million Catalog (Volchkov et al. 1992, Ed. by A.P.Gulyaev and V.V. Nesterov, Mosk. Gos. Univ., Moscow, p. 67) and in the case the last three catalogs are reduced to the Hipparcos system. The parameters of the velocity distribution of halo (U0, V0, W0) = ( -9+/-12, -214+/-10, -16+/-7) km/s and thick-disk (U0, V0, W0) = (-16+/-8, -41+/-7, -18+/-5) km/s RR Lyrae subsamples are inferred as well as the intensity-averaged absolute magnitudes of the corresponding populations: <MV> = 0.77+/-0.10 and <MV> = +1.11+/-0.28 for halo and thickdisk objects, respectively.
- ID:
- ivo://CDS.VizieR/J/ApJ/689/L149
- Title:
- Parameter variations of Gliese 436b transits
- Short Name:
- J/ApJ/689/L149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ground-based observations of the transiting Neptune-mass planet Gl 436b obtained with the 3.5m telescope at Apache Point Observatory and other supporting telescopes. Included in this is an observed transit in early 2005, over 2 years before the earliest reported transit detection. We have compiled all available transit data to date and perform a uniform modeling using the JKTEBOP code. We do not detect any transit timing variations of amplitude greater than ~1 minute over the ~3.3 year baseline. We do however find possible evidence for a self-consistent trend of increasing orbital inclination, transit width, and transit depth, which supports the supposition that Gl 436b is being perturbed by another planet of <~12M_{earth}_ in a nonresonant orbit.
- ID:
- ivo://CDS.VizieR/II/171
- Title:
- Parenago Catalog of Stars in Orion Nebula
- Short Name:
- II/171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The present catalogue is a machine-readable version of the catalogue of stars in the area of the Orion nebula, published by P.P. Parenago (1954). The sky area between 5h 24m and 5h 36m in right ascension (1900.0) and between -4 and -7 degrees in declination (1900.0), containing the Orion nebula, has been investigated in that work. Ten of variable stars in original Parenago (1954) catalogue had CSV numbers (Kukarkin et al., 1951) but since that time all of them were confirmed as variables and included in GCVS (Kholopov et al., 1985a&b, 1987). We superseded CSV-numbers by GCVS-names in the machine-readable version for the following stars: ------------------------------------------------ Number in CSV-number GCVS-name the catalogue ------------------------------------------------ 1605 606 V372 ORI 1613 607 V373 ORI 1635 608 V374 ORI 1713 609 V375 ORI 1748 610 V387 ORI 1762 100569 V376 ORI 1974 617 V377 ORI 2183 625 V388 ORI 2393 630 V380 ORI 2478 634 V381 ORI ------------------------------------------------
- ID:
- ivo://CDS.VizieR/J/A+A/640/A13
- Title:
- Par-Lup3-4 CO ALMA images
- Short Name:
- J/A+A/640/A13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Very low-mass stars are known to have jets and outflows, which is indicative of a scaled-down version of low-mass star formation. However, only very few outflows in very low-mass sources are well characterized. We characterize the bipolar molecular outflow of the very low-mass star Par-Lup3-4, a 0.12M_{sun}_ object known to power an optical jet. We observed Par-Lup3-4 with ALMA in Bands 6 and 7, detecting both the continuum and CO molecular gas. In particular, we studied three main emission lines: CO(2-1), CO(3-2), and ^13^CO(3-2). Our observations reveal for the first time the base of a bipolar molecular outflow in a very low-mass star, as well as a stream of material moving perpendicular to the primary outflow of this source. The primary outflow morphology is consistent with the previously determined jet orientation and disk inclination. The outflow mass is 9.5x10^-7^M_{sun}_, with an outflow rate of 4.3x10^-9^M_{sun}_/yr. A new fitting to the spectral energy distribution suggests that Par-Lup3-4 may be a binary system. We have characterized Par-Lup3-4 in detail, and its properties are consistent with those reported in other very low-mass sources. This source provides further evidence that very low-mass sources form as a scaled-down version of low-mass stars.
- ID:
- ivo://CDS.VizieR/J/A+A/480/495
- Title:
- Patterns of color variations in close binaries
- Short Name:
- J/A+A/480/495
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the first of a series of papers in which we present the results of a long-term photometric monitoring project carried out at Catania Astrophysical Observatory aimed at studying magnetic activity in late-type components of close binary systems, its dependence on global stellar parameters, and its evolution on different time scales from days to years. In this first paper, we present the complete observation dataset and new results of an investigation into the origin of brightness and color variations observed in the well-known magnetically active close binary stars: AR Psc, VY Ari, UX Ari, V711 Tau, EI Eri, V1149 Ori, DH Leo, HU Vir, RS CVn, V775 Her, AR Lac, SZ Psc, II Peg and BY Dra . About 38000 high-precision photoelectric nightly observations in the U, B and V filters are analysed. Correlation and regression analyses of the V magnitude vs. U-B and B-V color variations are carried out and a comparison with model variations for a grid of active region temperature and filling factor values is also performed. We find the existence of two different patterns of color variation. Eight stars in our sample: BY Dr, VY Ari, V775 Her, II Peg, V1149 Ori, HU Vir, EI Eri and DH Leo become redder when they become fainter, as is expected from the presence of active regions consisting of cool spots. The other six stars show the opposite behaviour, i.e. they become bluer when they become fainter. For V711 Tau this behaviour could be explained by the increased relative U- and B- flux contribution by the earlier-type component of the binary system when the cooler component becomes fainter. On the other hand, for AR Psc, UX Ari, RS CVn, SZ Psc and AR Lac the existence of hot photospheric faculae must be invoked. We also found that in single-lined and double-lined binary stars in which the fainter component is inactive or much less active the V magnitude is correlated to B-V and U-B color variations in more than 60% of observation seasons. The correlation is found in less than 40% of observation seasons when the fainter component has a non-negligible level of activity and/or hot faculae are present but they are either spatially or temporally uncorrelated to spots.
- ID:
- ivo://CDS.VizieR/J/AJ/139/2269
- Title:
- P Cyg H{alpha} squared visibility
- Short Name:
- J/AJ/139/2269
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High spatial resolution observations of the H{alpha}-emitting wind structure associated with the luminous blue variable star P Cygni were obtained with the Navy Prototype Optical Interferometer. These observations represent the most comprehensive interferometric data set on P Cyg to date. We demonstrate how the apparent size of the H{alpha}-emitting region of the wind structure of P Cyg compares between the 2005, 2007, and 2008 observing seasons and how this relates to the H{alpha} line spectroscopy. Using the data sets from 2005, 2007, and 2008 observing seasons, we fit a circularly symmetric Gaussian model to the interferometric signature from the H#-emitting wind structure of P Cyg.
- ID:
- ivo://CDS.VizieR/J/AJ/141/120
- Title:
- P Cygni H{alpha} measurements
- Short Name:
- J/AJ/141/120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- P Cygni is a prototype of the luminous blue variables (or S Doradus variables), and the star displays photometric and emission line variability on a timescale of years (known as the "short S Doradus-phase" variations). Here we present new high-resolution H{alpha} spectroscopy of P Cyg that we combine with earlier spectra and concurrent V-band photometry to document the emission and continuum flux variations over a 24 year time span.
- ID:
- ivo://CDS.VizieR/J/ApJ/863/151
- Title:
- Period analysis of 7 field RRab stars
- Short Name:
- J/ApJ/863/151
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the times of light maximum collected from the GEOS RR Lyrae database and determined from sky surveys, we utilize the O-C method to study the period variations of seven field ab-type RR Lyrae stars. The time coverage of data for most stars is more than 100 years, allowing us to investigate period changes over a large time span. We find that the O-C diagrams for most stars can be described by a combination of cyclic variations and long-term period changes. Assuming the former were caused by the light-travel-time effect, the pulsation and orbital parameters are obtained by the nonlinear fitting. We find that the orbital periods in our sample range from 33 to 78 years, and the eccentricities are relatively higher than the results for other candidates (e>0.6). The minimal masses of the potential companions of XX And, BK Dra, and RY Psc are less than one solar mass, and those of SV Eri, AR Her, and RU Scl are 3.3, 2.1, and 3.4M_{sun}_, respectively. Moreover, we suggest that the companion of AR Her may be a blue straggler that experienced mass transfer or a merger of two stars. The O-C diagram for ST Vir also shows distinct long- term period decrease, and in the O-C residuals, additional quasi-periodic variations that can be described by damped oscillation are found. Combining the data from the literature and our analysis, we plot the log P-AO-C diagram. The distribution of our binary candidates suggests that their period variations are not caused by the Blazhko effect.
- 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.
