- ID:
- ivo://CDS.VizieR/J/AJ/161/72
- Title:
- 180 Transit and occultation times for WASP-12b
- Short Name:
- J/AJ/161/72
- Date:
- 10 Dec 2021
- Publisher:
- CDS
- Description:
- Theory suggests that the orbits of some close-in giant planets should decay due to tidal interactions with their host stars. To date, WASP-12b is the only hot Jupiter reported to have a decaying orbit, at a rate of 29{+/-}2ms/yr. We analyzed data from NASA's Transiting Exoplanet Survey Satellite (TESS) to verify that WASP-12b's orbit is indeed changing. We find that the TESS transit and occultation data are consistent with a decaying orbit with an updated period of 1.091420090{+/-}0.000000041days and a decay rate of 32.53{+/-}1.62ms/yr. We find an orbital decay timescale of {tau}=P/|P|=2.90{+/-}0.14Myr. If the observed decay results from tidal dissipation, the modified tidal quality factor is Q_*_'=1.39{+/-}0.15x10^5^, which falls at the lower end of values derived for binary star systems and hot Jupiters. Our result highlights the power of space-based photometry for investigating the orbital evolution of short-period exoplanets.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/657/A102
- Title:
- Transit events of 4 extrasolar planets
- Short Name:
- J/A+A/657/A102
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Meter-sized ground-based telescopes are frequently used today for the follow-up of extrasolar planet candidates. While the transit signal of a Jupiter-sized object can typically be detected to a high level of confidence with small telescope apertures as well, the shallow transit dips of planets with the size of Neptune and smaller are more challenging to reveal. We employ new observational data to illustrate the photometric follow-up capabilities of meter-sized telescopes for shallow exoplanet transits. We describe in detail the capability of distinguishing the photometric signal of an exoplanet transit from an underlying trend in the light curve. The transit depths of the six targets we observed, Kepler-94b, Kepler-63b, K2-100b, K2-138b, K2-138c, and K2-138e, range from 3.9ppt down to 0.3ppt. For five targets of this sample, we provide the first ground-based photometric follow-up. The timing of three targets is precisely known from previous observations, and the timing of the other three targets is uncertain and we aim to constrain it. We detect or rule out the transit features significantly in single observations for the targets that show transits of 1.3ppt or deeper. The shallower transit depths of two targets of 0.6 and 0.8ppt were detected tentatively in single light curves, and were detected significantly by repeated observations. Only for the target of the shallowest transit depth of 0.3ppt were we unable to draw a significant conclusion despite combining five individual light curves. An injection-recovery test on our real data shows that we detect transits of 1.3ppt depth significantly in single light curves if the transit is fully covered, including out-of-transit data toward both sides, in some cases down to 0.7ppt depth. For Kepler-94b, Kepler-63b, and K2-100b, we were able to verify the ephemeris. In the case of K2-138c with a 0.6ppt deep transit, we were able to refine it, and in the case of K2-138e, we ruled out the transit in the time interval of more than +/-1.5{sigma} of its current literature ephemeris.
- ID:
- ivo://CDS.VizieR/J/AJ/154/49
- Title:
- Transiting Exoplanet Monitoring Project. II. HAT-P-33
- Short Name:
- J/AJ/154/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 10 R-band photometric observations of eight different transits of the hot Jupiter HAT-P-33b, which has been targeted by our Transiting Exoplanet Monitoring Project. The data were obtained by two telescopes at the Xinglong Station of National Astronomical Observatories of China (NAOC) from 2013 December through 2016 January, and exhibit photometric scatter of 1.6-3.0mmag. After jointly analyzing the previously published photometric data, radial-velocity (RV) measurements, and our new light curves, we revisit the system parameters and orbital ephemeris for the HAT-P-33b system. Our results are consistent with the published values except for the planet to star radius ratio (R_P_/R_*_), the ingress/egress duration ({tau}) and the total duration (T_14_), which together indicate a slightly shallower and shorter transit shape. Our results are based on more complete light curves, whereas the previously published work had only one complete transit light curve. No significant anomalies in Transit Timing Variations (TTVs) are found, and we place upper mass limits on potential perturbers, largely supplanting the loose constraints provided by the extant RV data. The TTV limits are stronger near mean-motion resonances, especially for the low-order commensurabilities. We can exclude the existence of a perturber with mass larger than 0.6, 0.3, 0.5, 0.5, and 0.3M_{Earth}_ near the 1:3, 1:2, 2:3, 3:2, and 2:1 resonances, respectively.
- ID:
- ivo://CDS.VizieR/J/MNRAS/506/3810
- Title:
- 7 transiting exoplanets CHEOPS light curves
- Short Name:
- J/MNRAS/506/3810
- Date:
- 03 Dec 2021 00:34:45
- Publisher:
- CDS
- Description:
- We present 17 transit light curves of seven known warm-Jupiters observed with the CHaracterising ExOPlanet Satellite (CHEOPS). The light curves have been collected as part of the CHEOPS Guaranteed Time Observation (GTO) program that searches for transit-timing variation (TTV) of warm-Jupiters induced by a possible external perturber to shed light on the evolution path of such planetary systems. We describe the CHEOPS observation process, from the planning to the data analysis. In this work we focused on the timing performance of CHEOPS, the impact of the sampling of the transit phases, and the improvement we can obtain combining multiple transits together. We reached the highest precision on the transit time of about 13-16s for the brightest target (WASP-38, G=9.2) in our sample. From the combined analysis of multiple transits of fainter targets with G>=11 we obtained a timing precision of ~2min. Additional observations with CHEOPS, covering a longer temporal baseline, will further improve the precision on the transit times and will allow us to detect possible TTV signals induced by an external perturber.
- ID:
- ivo://CDS.VizieR/J/MNRAS/428/678
- Title:
- Transiting exoplanet TrES-3b CCD UBVR photometry
- Short Name:
- J/MNRAS/428/678
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We observed nine primary transits of the hot Jpiter TrES-3b in several optical and near-UV photometric bands from 2009 June to 2012 April in an attempt to detect its magnetic field. Vidotto, Jardine and Helling suggest that the magnetic field of TrES-3b can be constrained if its near-UV light curve shows an early ingress compared to its optical light curve, while its egress remains unaffected. Predicted magnetic field strengths of Jupiter-like planets should range between 8G and 30G. Using these magnetic field values and an assumed B* of 100G, the Vidotto et al. method predicts a timing difference of 5-11min. We did not detect an early ingress in our three nights of near-UV observations, despite an average cadence of 68 s and an average photometric precision of 3.7mmag. However, we determined an upper limit of TrES-3b's magnetic field strength to range between 0.013 and 1.3G (for a 1-100G magnetic field strength range for the host star, TrES-3) using a timing difference of 138s derived from the Nyquist-Shannon sampling theorem. To verify our results of an abnormally small magnetic field strength for TrES-3b and to further constrain the techniques of Vidotto et al., we propose future observations of TrES-3b with other platforms capable of achieving a shorter near-UV cadence. We also present a refinement of the physical parameters of TrES-3b, an updated ephemeris and its first published near-UV light curve. We find that the near-UV planetary radius of Rp=1.386+0.248-0.144RJup is consistent with the planet's optical radius.
- ID:
- ivo://CDS.VizieR/J/A+A/553/A44
- Title:
- Transiting extrasolar planet WASP-33b
- Short Name:
- J/A+A/553/A44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- HD 15082 (WASP-33) is the hottest and fastest rotating star known to harbor a transiting extrasolar planet (WASP-33b) The lack of high precision radial velocity (RV) data stresses the need for precise light curve analysis and gathering further RV data. By using available photometric and RV data, we perform a blend analysis, compute more accurate system parameters, confine the planetary mass and attempt to cast light on the observed transit anomalies. We combine the original HATNet observations and various followup data to jointly analyze the signal content and extract the transit component and use our RV data to aid the global parameter determination. The blend analysis of the combination of multicolor light curves yields the first independent confirmation of the planetary nature of WASP-33b. We clearly identify three frequency components in the 15-21c/d regime with amplitudes 5-7mmag. These frequencies correspond to the delta Scuti-type pulsation of the host star. None of these pulsation frequencies or their low-order linear combinations are in close resonance with the orbital frequency. We show that these pulsation components explain some but not all of the observed transit anomalies. The grand-averaged transit light curve shows that there is a ~1.5mmag brightening shortly after the planet passes the mid-transit phase. Although the duration and amplitude of this brightening varies, it is visible even through the direct inspections of the individual transit events (some 40-60% of the followup light curves show this phenomenon). We suggest that the most likely explanation of this feature is the presence of a well-populated spot belt which is highly inclined to the orbital plane. This geometry is consistent with the inference from the spectroscopic anomalies. Finally, we constrain the planetary mass to M_p_=3.27+/-0.73M_J_ by using our RV data collected by the TRES spectrograph.
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/1338
- Title:
- Transiting planetary system WASP-17
- Short Name:
- J/MNRAS/426/1338
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric observations of four transits in the WASP-17 planetary system, obtained using telescope defocusing techniques and with scatters reaching 0.5mmag per point. Our revised orbital period is 4.0+/-0.6s longer than previous measurements, a difference of 6.6{sigma}, and does not support the published detections of orbital eccentricity in this system. We model the light curves using the JKTEBOP code and calculate the physical properties of the system by recourse to five sets of theoretical stellar model predictions. The resulting planetary radius, Rb=1.932+/-0.052+/-0.010R_Jup_ (statistical and systematic errors, respectively), provides confirmation that WASP-17b is the largest planet currently known. All 14 planets with radii measured to be greater than 1.6R_Jup_are found around comparatively hot (T_eff_>5900K) and massive (M_A_>1.15M_{sun}_) stars. Chromospheric activity indicators are available for eight of these stars, and all imply a low activity level. The planets have small or zero orbital eccentricities, so tidal effects struggle to explain their large radii.
- ID:
- ivo://CDS.VizieR/J/MNRAS/408/1680
- Title:
- Transiting planetary system WASP-2
- Short Name:
- J/MNRAS/408/1680
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-precision photometry of three transits of the extrasolar planetary system WASP-2, obtained by defocussing the telescope, and achieving point-to-point scatters of between 0.42 and 0.73mmag. These data are modelled using the JKTEBOP code, and taking into account the light from the recently-discovered faint star close to the system. The physical properties of the WASP-2 system are derived using tabulated predictions from five different sets of stellar evolutionary models, allowing both statistical and systematic error bars to be specified. We find the mass and radius of the planet to be M_b_=0.847+/-0.038+/-0.024M_jup_ and R_b_=1.044+/-0.029+/-0.015R_jup_. It has a low equilibrium temperature of 1280+/-21K, in agreement with a recent finding that it does not have an atmospheric temperature inversion.
- ID:
- ivo://CDS.VizieR/J/A+A/527/A8
- Title:
- Transiting planetary system WASP-7
- Short Name:
- J/A+A/527/A8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first high-precision photometry of the transiting extrasolar planetary system WASP-7, obtained using telescope defocussing techniques and reaching a scatter of 0.68mmag per point. We find that the transit depth is greater and that the host star is more evolved than previously thought. The planet has a significantly larger radius and much lower density and surface gravity than previous measurements showed. Based on the revised properties it is no longer an outlier in planetary mass-radius and period-gravity diagrams. We obtain a more precise transit ephemeris for the WASP-7 system.
- ID:
- ivo://CDS.VizieR/J/ApJ/704/1107
- Title:
- Transiting planet candidates in HATNet field 205
- Short Name:
- J/ApJ/704/1107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HAT-P-8b, a transiting planet with mass M_p_=1.52^+0.18^_-0.16_M_J_, radius R_p_=1.50^+0.08^_-0.06_R_J_, and photometric period P=3.076days. HAT-P-8b has a somewhat inflated radius for its mass, and a somewhat large mass for its period. The host star is a solar-metallicity F dwarf, with mass M_*_=1.28+/-0.04M_{sun}_ and R_*_=1.58^+0.08^_-0.06R_{sun}_. HAT-P-8b was initially identified as one of the 32 transiting-planet candidates in HATNet field G205. We describe the procedures that we have used to follow up these candidates with spectroscopic and photometric observations, and we present a status report on our interpretation for 28 of the candidates. Eight are eclipsing binaries with orbital solutions whose periods are consistent with their photometric ephemerides; two of these spectroscopic orbits are single-lined and six are double-lined.
