- ID:
- ivo://CDS.VizieR/J/A+A/628/A115
- Title:
- WASP-12, CoRoT-1 and TrES-3 light curves
- Short Name:
- J/A+A/628/A115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the characterization of two engineered diffusers mounted on the 2.5-meter Nordic Optical Telescope, located at Roque de Los Muchachos, Spain. To assess the reliability and the efficiency of the diffusers, we carried out several test observations of two photometric standard stars, along with observations of one primary transit observation of TrES-3b in the red (R band), one of CoRoT-1b in the blue (B band), and three secondary eclipses of WASP-12b (V band). The achieved photometric precision is in all cases within the submillimagnitude level for exposures between 25 and 180 seconds. Along with a detailed analysis of the functionality of the diffusers, we add a new transit depth measurement in the blue (B band) to the already observed transmission spectrum of CoRoT-1b, disfavoring a Rayleigh slope. We also report variability of the eclipse depth of WASP-12b in the V band. For the WASP-12b secondary eclipses, we observe a secondary depth deviation of about 5 sigma, and a difference of 6 sigma and 2.5 sigma when compared to the values reported by other authors in a similar wavelength range determined from Hubble Space Telescope data. We further speculate about the potential physical processes or causes responsible for this observed variability.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/430/2932
- Title:
- WASP-44 griz light curves
- Short Name:
- J/MNRAS/430/2932
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ground-based broad-band photometry of two transits in the WASP-44 planetary system obtained simultaneously through four optical (Sloan g', r', i', z') and three near-infrared (NIR; J, H, K) filters. We achieved low scatters of 1-2mmag per observation in the optical bands with a cadence of roughly 48s, but the NIR-band light curves present much greater scatter. We also observed another transit of WASP-44 b by using a Gunn r filter and telescope defocussing, with a scatter of 0.37 mmag per point and an observing cadence around 135 s. We used these data to improve measurements of the time of mid- transit and the physical properties of the system. In particular, we improved the radius measurements of the star and planet by factors of 3 and 4, respectively. We find that the radius of WASP-44 b is 1.002+/-0.033+/-0.018RJup (statistical and systematic errors, respectively), which is slightly smaller than previously thought and differs from that expected for a core-free planet. In addition, with the help of a synthetic spectrum, we investigated the theoretically predicted variation of the planetary radius as a function of wavelength, covering the range 370-2440nm. We can rule out extreme variations at optical wavelengths, but unfortunately our data are not precise enough (especially in the NIR bands) to differentiate between the theoretical spectrum and a radius which does not change with wavelength. The resulting measurements of transit mid-points were fitted with a straight line to obtain a new orbital ephemeris: T0=BJD(TDB)2455434.37642(37)+2.4238133(23)xE, where E is the number of orbital cycles after the reference epoch [the mid-point of the first transit observed by Anderson et al. (2012, Cat. J/MNRAS/422/1988)] and quantities in parentheses denote the uncertainty in the final digit of the preceding number.
- ID:
- ivo://CDS.VizieR/J/A+A/642/A50
- Title:
- WASP-74 griz_s_ light curves
- Short Name:
- J/A+A/642/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new transit observations of the hot Jupiter WASP-74 b (Teq~1860K) using the high-resolution spectrograph HARPS-N and the multi-colour simultaneous imager MuSCAT2. We refined the orbital properties of the planet and its host star and measured its obliquity for the first time. The measured sky-projected angle between the stellar spin-axis and the orbital axis of the planet is compatible with an orbit that is well-aligned with the equator of the host star ({lambda}=0.77+/-0.99{deg}). We are not able to detect any absorption feature of H{alpha} or any other atomic spectral features in the high-resolution transmission spectra of this source owing to low S/N at the line cores. Despite previous claims regarding the presence of strong optical absorbers such as TiO and VO gases in the atmosphere of WASP-74 b, new ground-based photometry combined with a reanalysis of previously reported observations from the literature show a slope in the low-resolution transmission spectrum that is steeper than expected from Rayleigh scattering alone.
- ID:
- ivo://CDS.VizieR/J/AcA/70/203
- Title:
- WASP-148 Ground-based Photometric Observations
- Short Name:
- J/AcA/70/203
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The WASP-148 planetary system has a rare architecture with a transiting Saturn-mass planet on a tight orbit which is accompanied by a slightly more massive planet on a nearby outer orbit. Using new space-born photometry and ground-based follow-up transit observations and data available in literature, we performed modeling that accounts for gravitational interactions between both planets. Thanks to the new transit timing data for planet b, uncertainties of orbital periods and eccentricities for both planets were reduced relative to previously published values by a factor of 3-4. Variation in transit timing has an amplitude of about 20 min and can be easily followed-up with a 1-m class telescopes from the ground. An approximated transit ephemeris, which accounts for gravitational interactions with an accuracy up to 5 min, is provided. No signature of transits was found for planet c down to the Neptune-size regime. No other transiting companions were found down to a size of about 2.4 Earth radii for interior orbits. We notice, however, that the regime of terrestrial-size planets still remains unexplored in that system.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A80
- Title:
- WASP-80 photometric and radial velocity data
- Short Name:
- J/A+A/551/A80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a planet transiting the star WASP-80 (1SWASP J201240.26-020838.2; 2MASS J20124017-0208391; TYC 5165-481-1; BPM 80815; V=11.9, K=8.4). Our analysis shows this is a 0.55+/-0.04M_jup_, 0.95+/-0.03R_jup_ gas giant on a circular 3.07 day orbit around a star with a spectral type between K7V and M0V. This system produces one of the largest transit depths so far reported, making it a worthwhile target for transmission spectroscopy. We find a large discrepancy between the vsini* inferred from stellar line broadening and the observed amplitude of the Rossiter-McLaughlin effect. This can be understood either by an orbital plane nearly perpendicular to the stellar spin or by an additional, unaccounted for source of broadening.
- ID:
- ivo://CDS.VizieR/J/A+A/531/A24
- Title:
- WASP-23 photometric and radial velocity data
- Short Name:
- J/A+A/531/A24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of a new transiting planet in the southern hemisphere. It was found by the WASP-south transit survey and confirmed photometrically and spectroscopically by the 1.2m Swiss Euler telescope, LCOGT 2m Faulkes South Telescope, the 60cm TRAPPIST telescope, and the ESO 3.6m telescope. The orbital period of the planet is 2.94 days. We find that it is a gas giant with a mass of 0.88+/-0.10M_J_ and an estimated radius of 0.96+/-0.05R_J_. We obtained spectra during transit with the HARPS spectrograph and detect the Rossiter-McLaughlin effect despite its small amplitude.
- 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.
- 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.
