- ID:
- ivo://CDS.VizieR/J/AcA/70/1
- Title:
- WASP-18 Photometric timeseries and timing data
- Short Name:
- J/AcA/70/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From its discovery, the WASP-18 system with its massive transiting planet on a tight orbit was identified as a unique laboratory for studies on tidal planet-star interactions. In an analysis of Doppler data, which include five new measurements obtained with the HIRES/Keck-I instrument between 2012 and 2018, we show that the radial velocity signal of the photosphere following the planetary tidal potential can be distilled for the host star. Its amplitude is in agreement with both theoretical predictions of the equilibrium tide approximation and an ellipsoidal modulation observed in an orbital phase curve. Assuming a circular orbit, we refine system parameters using photometric time series from TESS. With a new ground-based photometric observation, we extend the span of transit timing observations to 28 years in order to probe the rate of the orbital period shortening. Since we found no departure from a constant-period model, we conclude that the modified tidal quality parameter of the host star must be greater than 3.9e6 with 95% confidence. This result is in line with conclusions drawn from studies of the population of hot Jupiters, predicting that the efficiency of tidal dissipation is 1 or 2 orders of magnitude weaker. As the WASP-18 system is one of the prime candidates for detection of orbital decay, further timing observations are expected to push the boundaries of our knowledge on stellar interiors.
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- ID:
- ivo://CDS.VizieR/J/A+A/588/L6
- Title:
- WASP-12 transit light curves
- Short Name:
- J/A+A/588/L6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Most hot Jupiters are expected to spiral in toward their host stars because the angular momentum of the orbital motion is transferred to the stellar spin. Their orbits can also precess as a result of planet-star interactions. Calculations show that both effects might be detected for the very-hot exoplanet WASP-12 b using the method of precise transit-timing over a time span of about 10yr. We acquired new precise light curves for 29 transits of WASP-12 b, spanning four observing seasons from November 2012 to February 2016. New mid-transit times, together with those from the literature, were used to refine the transit ephemeris and analyze the timing residuals. We find that the transit times of WASP-12 b do not follow a linear ephemeris with a 5-{sigma} confidence level. They may be approximated with a quadratic ephemeris that gives a change rate in the orbital period of (-2.56+/-0.40)x10^-2^s/yr. The tidal quality parameter of the host star was found to be equal to 2.5x10^5^, which is similar to theoretical predictions for Sun-like stars. We also considered a model in which the observed timing residuals are interpreted as a result of the apsidal precession. We find, however, that this model is statistically less probable than the orbital decay.
- ID:
- ivo://CDS.VizieR/J/MNRAS/457/4205
- Title:
- WASP-22, WASP-41, WASP-42, WASP-55
- Short Name:
- J/MNRAS/457/4205
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 13 high-precision and four additional light curves of four bright southern-hemisphere transiting planetary systems: WASP-22, WASP-41, WASP-42 and WASP-55. In the cases of WASP-42 and WASP-55, these are the first follow-up observations since their discovery papers. We present refined measurements of the physical properties and orbital ephemerides of all four systems. No indications of transit timing variations were seen. All four planets have radii inflated above those expected from theoretical models of gas-giant planets; WASP-55 b is the most discrepant with a mass of 0.63M_Jup_ and a radius of 1.34R_Jup_. WASP-41 shows brightness anomalies during transit due to the planet occulting spots on the stellar surface. Two anomalies observed 3.1d apart are very likely due to the same spot. We measure its change in position and determine a rotation period for the host star of 18.6+/-1.5d, in good agreement with a published measurement from spot-induced brightness modulation, and a sky-projected orbital obliquity of {lambda}=6+/-11{deg}. We conclude with a compilation of obliquity measurements from spot-tracking analyses and a discussion of this technique in the study of the orbital configurations of hot Jupiters.
- ID:
- ivo://CDS.VizieR/J/AJ/154/118
- Title:
- WD+dMs from the SUPERBLINK proper motion survey
- Short Name:
- J/AJ/154/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an activity and kinematic analysis of high proper motion white dwarf-M dwarf binaries (WD+dMs) found in the SUPERBLINK survey, 178 of which are new identifications. To identify WD+dMs, we developed a UV-optical-IR color criterion and conducted a spectroscopic survey to confirm each candidate binary. For the newly identified systems, we fit the two components using model white dwarf spectra and M dwarf template spectra to determine physical parameters. We use H{alpha} chromospheric emission to examine the magnetic activity of the M dwarf in each system, and investigate how its activity is affected by the presence of a white dwarf companion. We find that the fraction of WD+dM binaries with active M dwarfs is significantly higher than their single M dwarf counterparts at early and mid-spectral types. We corroborate previous studies that find high activity fractions at both close and intermediate separations. At more distant separations, the binary fraction appears to approach the activity fraction for single M dwarfs. Using derived radial velocities and the proper motions, we calculate 3D space velocities for the WD+dMs in SUPERBLINK. For the entire SUPERBLINK WD+dMs, we find a large vertical velocity dispersion, indicating a dynamically hotter population compared to high proper motion samples of single M dwarfs. We compare the kinematics for systems with active M dwarfs and those with inactive M dwarfs, and find signatures of asymmetric drift in the inactive sample, indicating that they are drawn from an older population.
- ID:
- ivo://CDS.VizieR/J/MNRAS/482/715
- Title:
- WD luminosity functions from the PS1 3pi Survey
- Short Name:
- J/MNRAS/482/715
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A large sample of white dwarfs is selected by both proper motion and colours from the Pan-STARRS 1 3{pi} Steradian Survey Processing Version 2 to construct the white dwarf luminosity functions of the discs and halo in the solar neighbourhood. Four-parameter astrometric solutions were recomputed from the epoch data. The generalized maximum volume method is then used to calculate the density of the populations. After removal of crowded areas near the Galactic plane and centre, the final sky area used by this work is 7.833sr, which is 83 per cent of the 3{pi} sky and 62 per cent of the whole sky. By dividing the sky using Voronoi tessellation, photometric and astrometric uncertainties are recomputed at each step of the integration to improve the accuracy of the maximum volume. Interstellar reddening is considered throughout the work. We find a disc-to-halo white dwarf ratio of about 100.
- ID:
- ivo://CDS.VizieR/J/A+A/445/423
- Title:
- WeCAPP Survey. M31 variables
- Short Name:
- J/A+A/445/423
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The observations in the WeCAPP microlensing survey towards the Andromeda galaxy (M31) for a period of three years (2000-2003) resulted in a database with unprecedented time coverage for an extragalactic variable star study. We have monitored a 16.1' x 16.6' field centered on the nucleus of M31 in two optical bands (R and I) using the 0.8-m telescope at Wendelstein, Germany and the 1.2-m telescope at Calar Alto, Spain. Using the difference imaging method we detected 23781 variable sources for which we calculated the periods and variation amplitudes. We classified the variables according to their position in the R-band period-amplitude plane. Three groups can be distinguished; while the first two groups can be mainly associated with Cepheid-like variables (population I Cepheids in group I; type II Cepheids and RV Tauri stars in group II), the third one consists of Long Period Variables (LPVs). We detected 37 RV Tauri stars and 11 RV Tauri candidates, which makes this catalogue one of the largest collections of this class of stars to date. The classification scheme is supported by Fourier decomposition of the light curves. The catalogue of variable stars contains the positions, the periods in R and I, the significance of the assigned periods, and the variation amplitudes in the R and I bands.
- ID:
- ivo://CDS.VizieR/J/ApJS/243/15
- Title:
- WERGS. II. SED fitting with optical, IR & radio data
- Short Name:
- J/ApJS/243/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present physical properties of radio galaxies (RGs) with f_1.4GHz_>1mJy discovered by Subaru Hyper Suprime-Cam (HSC) and Very Large Array Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. For 1056 FIRST RGs at 0<z<=1.7 with HSC counterparts in about 100deg^2^, we compiled multi-wavelength data of optical, near-infrared (IR), mid-IR, far-IR, and radio (150MHz). We derived their color excess (E(B-V)_*_), stellar mass, star formation rate (SFR), IR luminosity, the ratio of IR and radio luminosity (q_IR_), and radio spectral index ({alpha}_radio_) that are derived from the spectral energy distribution (SED) fitting with CIGALE. We also estimated Eddington ratio based on stellar mass and integration of the best-fit SEDs of active galactic nucleus (AGN) component. We found that E(B-V)_*_, SFR, and IR luminosity clearly depend on redshift while stellar mass, q_IR_, and {alpha}_radio_ do not significantly depend on redshift. Since optically faint (i_AB_>=21.3) RGs that are newly discovered by our RG survey tend to be high redshift, they tend to not only have a large dust extinction and low stellar mass but also have high SFR and AGN luminosity, high IR luminosity, and high Eddington ratio compared with optically bright ones. The physical properties of a fraction of RGs in our sample seem to differ from a classical view of RGs with massive stellar mass, low SFR, and low Eddington ratio, demonstrating that our RG survey with HSC and FIRST provides us curious RGs among entire RG population.
- ID:
- ivo://CDS.VizieR/J/A+A/466/137
- Title:
- Westerlund 2 JHKs photometry
- Short Name:
- J/A+A/466/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometry for the stars detected with SOFI, NTT in J, H and Ks in the field containing the massive cluster Westerlund 2 (also know as RCW 49) associated with the HII region Gum29. For each star detected in all three bands the table contains the ID, equatorial coordinates, J, H and Ks magnitude and photometric errors. For the stars detected only in Ks or in H and Ks the magnitude and photometric error fields in the absent bands are filled with the values 99.99 and 9.999 respectively.
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/3797
- Title:
- Westerlund 2 UBVIc photometry
- Short Name:
- J/MNRAS/446/3797
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep UBVI_c_ photometric data of the young open cluster Westerlund 2. An abnormal reddening law of R_V,cl_=4.14+/-0.08 was found for the highly reddened early-type members (E(B-V)>=1.45), whereas a fairly normal reddening law of R_V,fg_=3.33+/-0.03 was confirmed for the foreground early-type stars (E(B-V)_fg_<1.05). The distance modulus was determined from zero-age main-sequence fitting to the reddening-corrected colour-magnitude diagram of the early-type members to be V_0_-M_V_=13.9+/-0.14 (random error) _-0.1_^+0.4^ (the upper limit of systematic error) mag (d=6.0+/-0.4_-0.3_^+1.2^kpc). To obtain te initial mass function, pre-main-sequence (PMS) stars were selected by identifying the optical counterparts of Chandra X-ray sources and mid-infrared emission stars from the Spitzer GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire) source catalogue. The initial mass function shows a shallow slope of {Gamma}=-1.1+/-0.1 down to log(m)=0.7. The total mass of Westerlund 2 is estimated to be at least 7400M_{sun}_. The age of Westerlund 2 from the main-sequence turn-on and PMS stars is estimated to be <~1.5Myr. We confirmed the existence of a clump of PMS stars located ~1-arcmin north of the core of Westerlund 2, but we could not find any clear evidence for an age difference between the core and the northern clump.
- ID:
- ivo://CDS.VizieR/J/A+A/573/A100
- Title:
- WFCAM Variable Star Catalog
- Short Name:
- J/A+A/573/A100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stellar variability in the near-infrared (NIR) remains largely unexplored. The exploitation of public science archives with data-mining methods offers a perspective for a time-domain exploration of the NIR sky. We perform a comprehensive search for stellar variability using the optical-NIR multiband photometric data in the public Calibration Database of the WFCAM Science Archive (WSA), with the aim of contributing to the general census of variable stars and of extending the current scarce inventory of accurate NIR light curves for a number of variable star classes.
