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22211. Three O-type binaries photometry in LMC
ID:
ivo://CDS.VizieR/J/ApJ/789/139
Title:
Three O-type binaries photometry in LMC
Short Name:
J/ApJ/789/139
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the second paper in a series devoted to the study of massive binary systems in the Large Magellanic Cloud (LMC). We mainly aim to provide accurate data that constrains the mass-luminosity relation for the most massive stars but also to address the long lasting problem known as the "mass discrepancy." We present here our results for three binaries (LMC 169782, LMC 171520, and [P93] 921) harboring the earliest O-type components-ranging from O4 V to O6.5 V-among our sample of 17 systems. Our photometry provided accurate periods for the studied systems, allowing the spectroscopic observations to be performed at selected phases where the radial velocity separation between binary components is larger. Following the procedure outlined in our first paper of this series, after solving the radial velocity curves for orbital parameters, we used tomographic reconstruction to obtain the individual spectra of each star, from which we determined effective temperatures via a model atmosphere fitting with FASTWIND. This information, combined with the light-curve analysis that was performed with GENSYN, enabled the determination of absolute masses, radii, and bolometric luminosities that are compared with those predicted by modern stellar evolutionary models finding that they agree within the uncertainties. Nevertheless, the comparison seems to confirm the small differences found in the first paper of this series in the sense that the evolutionary masses are slightly larger than the Keplerian ones, with differences averaging ~10%, or alternatively, the stellar evolutionary models predict luminosities that are somewhat lower than observed. Still, the overall agreement between the current evolutionary models and the empirically determined stellar parameters is remarkable.
22212. Three short-period eclipsing binaries BVRI photometry
ID:
ivo://CDS.VizieR/J/AJ/154/260
Title:
Three short-period eclipsing binaries BVRI photometry
Short Name:
J/AJ/154/260
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper, we present new BVRI light curves of short-period contact eclipsing binaries V1101 Her and AD Phe from our observations carried out from 2014 to 2015 using the SARA KP and SARA CT telescopes. There is an eclipsing binary located at {alpha}(2000)=01h16m36.15s and {delta}(2000)=-39{deg}49'55.7" in the field of view of AD Phe. We derived an updated ephemeris and found there a cyclic variation overlaying a continuous period increase (V1101 Her) and decrease (AD Phe). This kind of cyclic variation may be attributed to the light time effect via the presence of the third body or magnetic activity cycle. The orbital period increase suggests that V1101 Her is undergoing a mass-transfer from the primary to the secondary component (dM_1_/dt=2.64(+/-0.11)x10^-6^ M_{sun}_/yr) with the third body (P3=13.9(+/-1.9) years), or 2.81(+/-0.07)x10^-6^ M_{sun}_/yr for an increase and magnetic cycle (12.4(+/-0.5) years). The long-term period decrease suggests that AD Phe is undergoing a mass-transfer from the secondary component to the primary component at a rate of -8.04(+/-0.09)x10^-8^ M_{sun}_/yr for a period decrease and the third body (P3=56.2(+/-0.8) years), or -7.11(+/-0.04)x10^-8^ M_{sun}_/yr for a decrease and magnetic cycle (50.3(+/-0.5) years). We determined their orbital and geometrical parameters. For AD Phe, we simultaneously analyzed our BVRI light curves and the spectroscopic observations obtained by Duerbeck & Rucinski (2007AJ....133..169D). The spectral type of V1101 Her was classified as G0+/-2V by LAMOST stellar spectra survey. The asymmetry of the R-band light curve of AD Phe obtained by McFarlane & Hilditch in 1987 (1987MNRAS.227..381M) is explained by a cool spot on the primary component.
22213. Three short-period, transiting exoplanets
ID:
ivo://CDS.VizieR/J/MNRAS/422/1988
Title:
Three short-period, transiting exoplanets
Short Name:
J/MNRAS/422/1988
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of three extrasolar planets that transit their moderately bright (m_V_=12-13) host stars. WASP-44b is a 0.89-M_Jup_ planet in a 2.42-day orbit around a G8V star. WASP-45b is a 1.03-M_Jup_ planet which passes in front of the limb of its K2V host star every 3.13-days. Weak CaII H&K emission seen in the spectra of WASP-45 suggests that the star is chromospherically active. WASP-46b is a 2.10-M_Jup_ planet in a 1.43-day orbit around a G6V star. Rotational modulation of the light curves of WASP-46 and weak CaII H&K emission in its spectra show the star to be photospherically and chromospherically active.
22214. Three transits of the exoplanet TrES-2
ID:
ivo://CDS.VizieR/J/ApJ/664/1185
Title:
Three transits of the exoplanet TrES-2
Short Name:
J/ApJ/664/1185
Date:
21 Oct 2021
Publisher:
CDS
Description:
Of the nearby transiting exoplanets that are amenable to detailed study, TrES-2 is both the most massive and the one with the largest impact parameter. We present z-band photometry of three transits of TrES-2. We improve on the estimates of the planetary, stellar, and orbital parameters, in conjunction with the spectroscopic analysis of the host star by Sozzetti and coworkers. We find the planetary radius to be Rp=1.222+/-0.038R_Jup_ and the stellar radius to be R*=1.003+/-0.027R_{sun}_. The quoted uncertainties include the systematic error due to the uncertainty in the stellar mass (M*=0.980+/-0.062 M_{sun}_) The timings of the transits have an accuracy of 25s and are consistent with a uniform period, thus providing a baseline for future observations with the NASA Kepler satellite, whose field of view will include TrES-2.
22215. 05 through L3 empirical stellar spectra from SDSS
ID:
ivo://CDS.VizieR/J/ApJS/230/16
Title:
05 through L3 empirical stellar spectra from SDSS
Short Name:
J/ApJS/230/16
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a library of empirical stellar spectra created using spectra from the Sloan Digital Sky Survey's Baryon Oscillation Spectroscopic Survey. The templates cover spectral types O5 through L3, are binned by metallicity from -2.0dex through +1.0dex, and are separated into main-sequence (dwarf) stars and giant stars. With recently developed M dwarf metallicity indicators, we are able to extend the metallicity bins down through the spectral subtype M8, making this the first empirical library with this degree of temperature and metallicity coverage. The wavelength coverage for the templates is from 3650 to 10200{AA} at a resolution of better than R~2000. Using the templates, we identify trends in color space with metallicity and surface gravity, which will be useful for analyzing large data sets from upcoming missions like the Large Synoptic Survey Telescope. Along with the templates, we are releasing a code for automatically (and/or visually) identifying the spectral type and metallicity of a star.
22216. THYME. IV. 3 Exoplanets around TOI-451 B
ID:
ivo://CDS.VizieR/J/AJ/161/65
Title:
THYME. IV. 3 Exoplanets around TOI-451 B
Short Name:
J/AJ/161/65
Date:
11 Mar 2022
Publisher:
CDS
Description:
Young exoplanets can offer insight into the evolution of planetary atmospheres, compositions, and architectures. We present the discovery of the young planetary system TOI-451 (TIC257605131, GaiaDR24844691297067063424). TOI-451 is a member of the 120Myr old Pisces-Eridanus stream (Psc-Eri). We confirm membership in the stream with its kinematics, its lithium abundance, and the rotation and UV excesses of both TOI451 and its wide-binary companion, TOI-451B (itself likely an M-dwarf binary). We identified three candidate planets transiting in the Transiting Exoplanet Survey Satellite data and followed up the signals with photometry from Spitzer and ground-based telescopes. The system comprises three validated planets at periods of 1.9, 9.2, and 16days, with radii of 1.9, 3.1, and 4.1 R, respectively. The host star is near-solar mass with V=11.0 and H=9.3 and displays an infrared excess indicative of a debris disk. The planets offer excellent prospects for transmission spectroscopy with the Hubble Space Telescope and the James Webb Space Telescope, providing the opportunity to study planetary atmospheres that may still be in the process of evolving.
22217. THYME. V. Discovering a new stellar association
ID:
ivo://CDS.VizieR/J/AJ/161/171
Title:
THYME. V. Discovering a new stellar association
Short Name:
J/AJ/161/171
Date:
08 Mar 2022
Publisher:
CDS
Description:
The detection and characterization of young planetary systems offer a direct path to study the processes that shape planet evolution. We report on the discovery of a sub-Neptune-sized planet orbiting the young star HD110082 (TOI-1098). Transit events we initially detected during TESS Cycle 1 are validated with time-series photometry from Spitzer. High-contrast imaging and high-resolution, optical spectra are also obtained to characterize the stellar host and confirm the planetary nature of the transits. The host star is a late-F dwarf (M*=1.2M{sun}) with a low-mass, M dwarf binary companion (M*=0.26M{sun}) separated by nearly one arcminute (~6200au). Based on its rapid rotation and Lithium absorption, HD110082 is young, but is not a member of any known group of young stars (despite proximity to the Octans association). To measure the age of the system, we search for coeval, phase-space neighbors and compile a sample of candidate siblings to compare with the empirical sequences of young clusters and to apply quantitative age-dating techniques. In doing so, we find that HD110082 resides in a new young stellar association we designate MELANGE-1, with an age of 250_-70_^+50^Myr. Jointly modeling the TESS and Spitzer light curves, we measure a planetary orbital period of 10.1827days and radius of Rp=3.2{+/-}0.1R{Earth}. HD110082b's radius falls in the largest 12% of field-age systems with similar host-star mass and orbital period. This finding supports previous studies indicating that young planets have larger radii than their field-age counterparts.
22218. THz spectrum of methylamine
ID:
ivo://CDS.VizieR/J/A+A/563/A137
Title:
THz spectrum of methylamine
Short Name:
J/A+A/563/A137
Date:
21 Oct 2021
Publisher:
CDS
Description:
Methylamine (CH_3_NH_2_) is the simplest primary alkylamine and has been detected in the interstellar medium. The molecule is relatively light, with the 50K Boltzmann peak appearing near 800GHz. However, reliable predictions for its rotational spectrum are available only up to 500GHz. Spectroscopic analyses have been complicated by the two large amplitude motions: internal rotation of the methyl top and inversion of the amino group. The aims is to provide reliable predictions of the methylamine ground state rotational spectrum above 500GHz we studied its rotational spectrum in the frequency range from 500 to 2650GHz. The spectra of methylamine were recorded using the spectrometers based on Schottky diode frequency multiplication chains in the Lille laboratory (500-945GHz) and in JPL (1060-2660GHz). The analysis of the rotational spectrum of methylamine in the ground vibrational state was performed on the basis of the group-theoretical high barrier tunneling Hamiltonian developed for methylamine by Ohashi and Hougen. In the recorded spectra we have assigned 1849 new rotational transitions of methylamine. They were fitted together with previously published data to a Hamiltonian model that uses 76 parameters with overall weighted rms deviation of 0.87. On the basis of the new spectroscopic results, predictions of transition frequencies in the frequency range up to 3THz with J<50 and Ka<20 are presented.
22219. THz spectrum of the monodeuterated methyl formate
ID:
ivo://CDS.VizieR/J/A+A/576/A39
Title:
THz spectrum of the monodeuterated methyl formate
Short Name:
J/A+A/576/A39
Date:
21 Oct 2021
Publisher:
CDS
Description:
Laboratory spectral recordings and accurate molecular spectral analysis of any potential interstellar molecule are essential to generate a complete spectroscopic line list. This permits the prediction of the frequencies and intensities of any transition for its subsequent identification in the interstellar medium. Present analysis of DCOOCH_3_ is aimed to provide a comprehensive spectral catalog that encompasses as much as possible the frequency coverage of the new generation far-IR and submillimeter wave observation facilities. A new measurement of the rotational spectrum of DCOOCH_3_ has been carried out in the JPL laboratory in the frequency range from 0.85 to 1.5 THz. The new data were analyzed jointly with literature data using the Rho Axis Method (RAM), a tool developed for the spectral analysis of molecules with large amplitude internal CH_3_ rotors. Twenty seven spectroscopic constants of DCOOCH_3_ have been fitted to 3763 transitions with maximum values of J=69 and Ka=36 of the ground torsional state with a standard (unitless) deviation of 0.97. With respect to prior work, this is a significantly better result that was obtained with 2060 more transitions while also achieving a better accuracy for the new parameter values.
22220. Ti and Fe lines in red supergiants
ID:
ivo://CDS.VizieR/J/ApJ/751/156
Title:
Ti and Fe lines in red supergiants
Short Name:
J/ApJ/751/156
Date:
21 Oct 2021
Publisher:
CDS
Description:
Detailed non-LTE (NLTE) calculations for red supergiant (RSG) stars are presented to investigate the influence of NLTE on the formation of atomic iron and titanium lines in the J band. With their enormous brightness at J band RSG stars are ideal probes of cosmic abundances. Recent LTE studies have found that metallicities accurate to 0.15 dex can be determined from medium-resolution spectroscopy of individual RSGs in galaxies as distant as 10 Mpc. The NLTE results obtained in this investigation support these findings. NLTE abundance corrections for iron are smaller than 0.05 dex for effective temperatures between 3400 K and 4200 K and 0.1 dex at 4400 K. For titanium the NLTE abundance corrections vary smoothly between -0.4 dex and +0.2 dex as a function of effective temperature. For both elements, the corrections also depend on stellar gravity and metallicity. The physical reasons behind the NLTE corrections and the consequences for extragalactic J-band abundance studies are discussed.

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