- ID:
- ivo://CDS.VizieR/J/AJ/156/94
- Title:
- APOGEE and Gaia DR2 analysis of IC 166
- Short Name:
- J/AJ/156/94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- IC 166 is an intermediate-age open cluster (OC) (~1 Gyr) that lies in the transition zone of the metallicity gradient in the outer disk. Its location, combined with our very limited knowledge of its salient features, make it an interesting object of study. We present the first high-resolution spectroscopic and precise kinematical analysis of IC 166, which lies in the outer disk with R_GC_~12.7 kpc. High-resolution H-band spectra were analyzed using observations from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment survey. We made use of the Brussels Automatic Stellar Parameter code to provide chemical abundances based on a line-by-line approach for up to eight chemical elements (Mg, Si, Ca, Ti, Al, K, Mn, and Fe). The {alpha}-element (Mg, Si, Ca, and whenever available Ti) abundances, and their trends with Fe abundances have been analyzed for a total of 13 high-likelihood cluster members. No significant abundance scatter was found in any of the chemical species studied. Combining the positional, heliocentric distance, and kinematic information, we derive, for the first time, the probable orbit of IC 166 within a Galactic model including a rotating boxy bar, and found that it is likely that IC 166 formed in the Galactic disk, supporting its nature as an unremarkable Galactic OC with an orbit bound to the Galactic plane.
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- ID:
- ivo://CDS.VizieR/J/AJ/156/18
- Title:
- APOGEE DR14:Binary companions of evolved stars
- Short Name:
- J/AJ/156/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multi-epoch radial velocity measurements of stars can be used to identify stellar, substellar, and planetary-mass companions. Even a small number of observation epochs can be informative about companions, though there can be multiple qualitatively different orbital solutions that fit the data. We have custom-built a Monte Carlo sampler (The Joker) that delivers reliable (and often highly multimodal) posterior samplings for companion orbital parameters given sparse radial velocity data. Here we use The Joker to perform a search for companions to 96231 red giant stars observed in the APOGEE survey (DR14) with >=3 spectroscopic epochs. We select stars with probable companions by making a cut on our posterior belief about the amplitude of the variation in stellar radial velocity induced by the orbit. We provide (1) a catalog of 320 companions for which the stellar companion's properties can be confidently determined, (2) a catalog of 4898 stars that likely have companions, but would require more observations to uniquely determine the orbital properties, and (3) posterior samplings for the full orbital parameters for all stars in the parent sample. We show the characteristics of systems with confidently determined companion properties and highlight interesting systems with candidate compact object companions.
- ID:
- ivo://CDS.VizieR/J/ApJS/236/27
- Title:
- APOGEE-2 survey of Orion Complex (OSFC). I.
- Short Name:
- J/ApJS/236/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Orion Star-forming Complex (OSFC) is a central target for the APOGEE-2 Young Cluster Survey. Existing membership catalogs span limited portions of the OSFC, reflecting the difficulty of selecting targets homogeneously across this extended, highly structured region. We have used data from wide-field photometric surveys to produce a less biased parent sample of young stellar objects (YSOs) with infrared (IR) excesses indicative of warm circumstellar material or photometric variability at optical wavelengths across the full 420deg^2^ extent of the OSFC. When restricted to YSO candidates with H<12.4, to ensure S/N~100 for a six-visit source, this uniformly selected sample includes 1307 IR excess sources selected using criteria vetted by Koenig & Leisawitz (2014ApJ...791..131K) and 990 optical variables identified in the Pan-STARRS1 3{pi} survey: 319 sources exhibit both optical variability and evidence of circumstellar disks through IR excess. Objects from this uniformly selected sample received the highest priority for targeting, but required fewer than half of the fibers on each APOGEE-2 plate. We filled the remaining fibers with previously confirmed and new color-magnitude selected candidate OSFC members. Radial velocity measurements from APOGEE-1 and new APOGEE-2 observations taken in the survey's first year indicate that ~90% of the uniformly selected targets have radial velocities consistent with Orion membership. The APOGEE-2 Orion survey will include >1100 bona fide YSOs whose uniform selection function will provide a robust sample for comparative analyses of the stellar populations and properties across all sub-regions of Orion.
- ID:
- ivo://CDS.VizieR/J/ApJ/764/8
- Title:
- APOSTLE r'-band transit lightcurves of TrES-3b
- Short Name:
- J/ApJ/764/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Apache Point Survey of Transit Lightcurves of Exoplanets (APOSTLE) observed 11 transits of TrES-3b over two years in order to constrain system parameters and look for transit timing and depth variations. We describe an updated analysis protocol for APOSTLE data, including the reduction pipeline, transit model, and Markov Chain Monte Carlo analyzer. Our estimates of the system parameters for TrES-3b are consistent with previous estimates to within the 2{sigma} confidence level. We improved the errors (by 10%-30%) on system parameters such as the orbital inclination (i_orb_), impact parameter (b), and stellar density ({rho}_{sstarf}_) compared to previous measurements. The near-grazing nature of the system, and incomplete sampling of some transits, limited our ability to place reliable uncertainties on individual transit depths and hence we do not report strong evidence for variability. Our analysis of the transit timing data shows no evidence for transit timing variations and our timing measurements are able to rule out super-Earth and gas giant companions in low-order mean motion resonance with TrES-3b.
- ID:
- ivo://CDS.VizieR/J/ApJ/770/36
- Title:
- APOSTLE transits of XO-2 system
- Short Name:
- J/ApJ/770/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Apache Point Survey of Transit Lightcurves of Exoplanets (APOSTLE) observed 10 transits of XO-2b over a period of 3yr. We present measurements that confirm previous estimates of system parameters like the normalized semi-major axis (a/R_*_), stellar density ({rho}_*_), impact parameter (b), and orbital inclination (i_orb_). Our errors on system parameters like a/R_*_ and {rho}_*_ have improved by ~40% compared to previous best ground-based measurements. Our study of the transit times show no evidence for transit timing variations (TTVs) and we are able to rule out co-planar companions with masses >=0.20M_{Earth}_ in low order mean motion resonance with XO-2b. We also explored the stability of the XO-2 system given various orbital configurations of a hypothetical planet near the 2:1 mean motion resonance. We find that a wide range of orbits (including Earth-mass perturbers) are both dynamically stable and produce observable TTVs. We find that up to 51% of our stable simulations show TTVs that are smaller than the typical transit timing errors (~20s) measured for XO-2b, and hence remain undetectable.
- ID:
- ivo://CDS.VizieR/J/AJ/128/463
- Title:
- A preliminary 20pc census from the NLTT catalogue
- Short Name:
- J/AJ/128/463
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Continuing our census of late-type dwarfs in the solar neighborhood, we present BVRI photometry and optical spectroscopy of 800 mid-type M dwarfs drawn from the NLTT proper-motion catalog. The targets are taken both from our own cross-referencing of the NLTT Catalogue and the 2MASS Second Incremental Data Release, and from the revised NLTT compiled recently by Salim & Gould (Cat. <J/ApJ/582/1011>). All are identified as nearby-star candidates based on their location in the (m_r_, m_r_-K_s_) diagram. Three hundred stars discussed here have previous astrometric, photometric, or spectroscopic observations. We present new BVRI photometry for 101 stars, together with low-resolution spectroscopy of a further 400 dwarfs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/460/650
- Title:
- Apsidal motions of 90 SMC eccentric binaries
- Short Name:
- J/MNRAS/460/650
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examined light curves of 1138 stars brighter than 18.0mag in the I band and less than a mean magnitude error of 0.1mag in the V band from the Optical Gravitational Lensing Experiment (OGLE)-III eclipsing binary catalogue, and found 90 new binary systems exhibiting apsidal motion. In this study, the samples of apsidal motion stars in the Small Magellanic Cloud (SMC) were increased by a factor of about 3.0 than previously known. In order to determine the period of the apsidal motion for the binaries, we analysed in detail both the light curves and eclipse timings using the MACHO (MAssive Compact Halo Objects) and OGLE photometric data base. For the eclipse timing diagrams of the systems, new times of minimum light were derived from the full light curve combined at intervals of one year from the survey data. The new 90 binaries have apsidal motion periods in the range of 12-897yr. An additional short-term oscillation was detected in four systems (OGLE-SMC-ECL-1634, 1947, 3035, and 4946), which most likely arises from the existence of a third body orbiting each eclipsing binary. Since the systems presented here are based on homogeneous data and have been analysed in the same way, they are suitable for further statistical analysis.
- ID:
- ivo://CDS.VizieR/J/other/NewA/48.42
- Title:
- AQ Boo VRI differential light curves
- Short Name:
- J/other/NewA/48.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We obtained the first VRI CCD light curves of the short-period contact eclipsing binary AQ Boo, which was observed on March 22 and April 19 in 2014 at Xinglong station of National Astronomical Observatories, and on January 20, 21 and February 28 in 2015 at Kunming station of Yunnan Observatories of Chinese Academy of Sciences, China. Using our six newly obtained minima and the minima that other authors obtained previously, we revised the ephemeris of AQ Boo. By fitting the O-C (observed minus calculated) values of the minima, the orbital period of AQ Boo shows a decreasing tendency dP/dt=-1.47(0.17)x10^-17^day/year. We interpret the phenomenon by mass transfer from the secondary (more massive) component to the primary (less massive) one. By using the updated Wilson & Devinney (1971ApJ...166..605W) program, we also derived the photometric orbital parameters of AQ Boo for the first time. We conclude that AQ Boo is a near contact binary with a low contact factor of 14.43%, and will become an over-contact system as the mass transfer continues.
- ID:
- ivo://CDS.VizieR/J/AJ/140/1475
- Title:
- ARAUCARIA: NGC 7793 Cepheids
- Short Name:
- J/AJ/140/1475
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For the first time, we have detected Cepheid variables in the Sculptor Group spiral galaxy NGC 7793. From wide-field images obtained in the optical V and I bands on 56 nights in 2003-2005, we have discovered 17 long-period (24-62 days) Cepheids whose periods and mean magnitudes define tight period-luminosity relations. We use the (V-I) Wesenheit index to determine a reddening-free true distance modulus to NGC 7793 of 27.68+/-0.05mag (internal error) +/-0.08mag (systematic error).
- ID:
- ivo://CDS.VizieR/J/ApJ/648/375
- Title:
- Araucaria: NGC 3109 Cepheids JK phot.
- Short Name:
- J/ApJ/648/375
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared J- and K-band photometry of 77 Cepheid variables in the Local Group galaxy NGC 3109. Combining our data with the previously published optical V- and I-band photometry of Cepheids in this galaxy, we derive an accurate distance and interstellar reddening toward NGC 3109.
