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2451. HAT-P-1b Ks-band secondary eclipse
ID:
ivo://CDS.VizieR/J/A+A/528/A49
Title:
HAT-P-1b Ks-band secondary eclipse
Short Name:
J/A+A/528/A49
Date:
21 Oct 2021
Publisher:
CDS
Description:
Only recently it has become possible to measure the thermal emission from hot-Jupiters at near-Infrared wavelengths using ground-based telescopes, by secondary eclipse observations. This allows the planet flux to be probed around the peak of its spectral energy distribution, which is vital for the understanding of its energy budget. The aim of the reported work is to measure the eclipse depth of the planet HAT-P-1b at 2.2micron. This planet is an interesting case, since the amount of stellar irradiation it receives falls in between that of the two best studied systems (HD209458 and HD189733), and it has been suggested to have a weak thermal inversion layer. We have used the LIRIS instrument on the William Herschel Telescope (WHT) to observe the secondary eclipse of HAT-P-1b in the Ks-band, as part of our Ground-based secondary eclipse (GROUSE) project. The observations were done in staring mode, while significantly defocusing the telescope to avoid saturation on the K=8.4 star. With an average cadence of 2.5 seconds, we collected 6520 frames during one night.
2452. HAT-P-12b 2016-2017 light curve
ID:
ivo://CDS.VizieR/J/A+A/620/A142
Title:
HAT-P-12b 2016-2017 light curve
Short Name:
J/A+A/620/A142
Date:
21 Oct 2021
Publisher:
CDS
Description:
Two independent investigations of the atmosphere of the hot Jupiter HAT-P-12b by two different groups resulted in discrepant solutions. Using broad-band photometry from the ground, one study found a flat and featureless transmission spectrum which was interpreted as a gray absorption by dense cloud coverage. The second study made use of the Hubble Space Telescope (HST) observations and found Rayleigh scattering at optical wavelengths caused by haze. The main purpose of this work is to find the source of this inconsistency and provide feedback to prevent similar discrepancies in future analyses of other exoplanetary atmospheres. We studied the observed discrepancy via two methods. With further broad-band observations in the optical wavelength regions, we strengthened the previous measurements in precision and with a homogeneous reanalysis of the published data, we managed to assess the systematic errors and the independent analyses of the two different groups. Repeating the analysis steps of both works, we found that deviating values for the orbital parameters are the reason for the aforementioned discrepancy. Our work showed a degeneracy of the planetary spectral slope with these parameters. In a homogeneous reanalysis of all data, the two literature data sets and the new observations converge to a consistent transmission spectrum, showing a low-amplitude spectral slope and a tentative detection of potassium absorption.
2453. HAT-P-1b transit light curves
ID:
ivo://CDS.VizieR/J/A+A/631/A169
Title:
HAT-P-1b transit light curves
Short Name:
J/A+A/631/A169
Date:
21 Oct 2021
Publisher:
CDS
Description:
Time-series spectrophotometric studies of exoplanets during transit using ground-based facilities are a promising approach to characterize their atmospheric compositions. We aim to investigate the transit spectrum of the hot Jupiter HAT-P-1b. We compare our results to those obtained at similar wavelengths by previous space-based observations. We observed two transits of HAT-P-1b with the Gemini Multi-Object Spectrograph (GMOS) instrument on the Gemini North telescope using two instrument modes covering the 320-800nm and 520-950nm wavelength ranges. We used time-series spectrophotometry to construct transit light curves in individual wavelength bins and measure the transit depths in each bin. We accounted for systematic effects. We addressed potential photometric variability due to magnetic spots in the planet's host star with long-term photometric monitoring. We find that the resulting transit spectrum is consistent with previous Hubble Space Telescope (HST) observations. We compare our observations to transit spectroscopy models that marginally favor a clear atmosphere. However, the observations are also consistent with a flat spectrum, indicating high-altitude clouds. We do not detect the Na resonance absorption line (589nm), and our observations do not have sufficient precision to study the resonance line of K at 770nm. We show that even a single Gemini/GMOS transit can provide constraining power on the properties of the atmosphere of HAT-P-1b to a level comparable to that of HST transit studies in the optical when the observing conditions and target and reference star combination are suitable. Our 520-950nm observations reach a precision comparable to that of HST transit spectra in a similar wavelength range of the same hot Jupiter, HAT-P-1b. However, our GMOS transit between 320-800nm suffers from strong systematic effects and yields larger uncertainties.
2454. HAT-P-31 differential photometry
ID:
ivo://CDS.VizieR/J/AJ/142/95
Title:
HAT-P-31 differential photometry
Short Name:
J/AJ/142/95
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of HAT-P-31b, a transiting exoplanet orbiting the V=11.660 dwarf star GSC 2099-00908. HAT-P-31b is the first planet discovered with the Hungarian-made Automated Telescope (HAT) without any follow-up photometry, demonstrating the feasibility of a new mode of operation for the HATNet project.
2455. HAT-P-25 differential photometry
ID:
ivo://CDS.VizieR/J/ApJ/745/80
Title:
HAT-P-25 differential photometry
Short Name:
J/ApJ/745/80
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of HAT-P-25b, a transiting extrasolar planet orbiting the V=13.19 G5 dwarf star GSC 1788-01237, with a period P=3.652836+/-0.000019days, transit epoch T_c_=2455176.85173+/-0.00047 (BJD - barycentric Julian dates throughout the paper are calculated from Coordinated Universal Time, UTC), and transit duration 0.1174+/-0.0017 days. The host star has a mass of 1.01+/-0.03M_{sun}_, radius of 0.96^+0.05^_-0.04_R_{sun}_, effective temperature 5500+/-80K, and metallicity [Fe/H]=+0.31+/-0.08. The planetary companion has a mass of 0.567+/-0.022 M_J_ and radius of 1.190^+0.081^_-0.056_R_J_ yielding a mean density of 0.42+/-0.07g/cm3.
2456. HAT-P-26 differential transit photometry
ID:
ivo://CDS.VizieR/J/A+A/628/A116
Title:
HAT-P-26 differential transit photometry
Short Name:
J/A+A/628/A116
Date:
21 Oct 2021
Publisher:
CDS
Description:
From its discovery, the low density transiting Neptune HAT-P-26b showed a 2.1 sigma detection drift in its spectroscopic data, while photometric data showed a weak curvature in the timing residuals that required further follow-up observations to be confirmed. To investigate this suspected variability, we observed 11 primary transits of HAT-P-26b between March, 2015 and July, 2018. For this, we used the 2.15 meter Jorge Sahade Telescope placed in San Juan, Argentina, and the 1.2 meter STELLA and the 2.5 meter Nordic Optical Telescope, both located in the Canary Islands, Spain. To add upon valuable information on the transmission spectrum of HAT-P-26b, we focused our observations in the R-band only. To contrast the observed timing variability with possible stellar activity, we carried out a photometric follow-up of the host star along three years. We carried out a global fit to the data and determined the individual mid-transit times focusing specifically on the light curves that showed complete transit coverage. Using bibliographic data corresponding to both ground and space-based facilities, plus our new characterized mid-transit times derived from parts-per-thousand precise photometry, we observed indications of transit timing variations in the system, with an amplitude of 4 minutes and a periodicity of 270 epochs. The photometric and spectroscopic follow-up observations of this system will be continued in order to rule out any aliasing effects caused by poor sampling and the long-term periodicity.
2457. HAT-P-30 follow-up photometry
ID:
ivo://CDS.VizieR/J/ApJ/735/24
Title:
HAT-P-30 follow-up photometry
Short Name:
J/ApJ/735/24
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of HAT-P-30b, a transiting exoplanet orbiting the V=10.419 dwarf star GSC 0208-00722. The planet has a period P=2.810595+/-0.000005 days, transit epoch T_c_=2455456.46561+/-0.00037 (BJD), and transit duration 0.0887+/-0.0015 days. The host star has a mass of 1.24+/-0.04M_{sun}_, radius of 1.21+/-0.05R_{sun}_, effective temperature of 6304+/-88K, and metallicity [Fe/H]=+0.13+/-0.08. The planetary companion has a mass of 0.711+/-0.028M_J_ and radius of 1.340+/-0.065R_J_ yielding a mean density of 0.37+/-0.05g/cm^3^. We also present radial velocity measurements that were obtained throughout a transit that exhibit the Rossiter-McLaughlin effect. By modeling this effect, we measure an angle of {lambda}=73.5+/-9.0{deg} between the sky projections of the planet's orbit normal and the star's spin axis. HAT-P-30b represents another example of a close-in planet on a highly tilted orbit, and conforms to the previously noted pattern that tilted orbits are more common around stars with T_eff*_>~6250K.
2458. HAT-P-39, HAT-P-40, and HAT-P-41 follow-up
ID:
ivo://CDS.VizieR/J/AJ/144/139
Title:
HAT-P-39, HAT-P-40, and HAT-P-41 follow-up
Short Name:
J/AJ/144/139
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of three new transiting extrasolar planets orbiting moderately bright (V=11.1, 11.7, and 12.4) F stars. The planets HAT-P-39b through HAT-P-41b have periods of P=3.5439days, 4.4572days, and 2.6940days, masses of 0.60M_J_, 0.62M_J_, and 0.80M_J_, and radii of 1.57R_J_, 1.73R _J_, and 1.68R_J_, respectively. They orbit stars with masses of 1.40 M _{sun}_, 1.51 M_{sun}_, and 1.51 M_{sun}_, respectively. The three planets are members of an emerging population of highly inflated Jupiters with 0.4M_J_<M<1.5M_J_ and R>1.5R_J_.
2459. HAT-P-44, HAT-P-45, and HAT-P-46 follow-up
ID:
ivo://CDS.VizieR/J/AJ/147/128
Title:
HAT-P-44, HAT-P-45, and HAT-P-46 follow-up
Short Name:
J/AJ/147/128
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery by the HATNet survey of three new transiting extrasolar planets orbiting moderately bright (V=13.2, 12.8, and 11.9) stars. The planets have orbital periods of 4.3012, 3.1290, and 4.4631 days, masses of 0.35, 0.89, and 0.49M_J_, and radii of 1.24, 1.43, and 1.28R_J_. The stellar hosts have masses of 0.94, 1.26, and 1.28M_{sun}_. Each system shows significant systematic variations in its residual radial velocities, indicating the possible presence of additional components. Based on its Bayesian evidence, the preferred model for HAT-P-44 consists of two planets, including the transiting component, with the outer planet having a period of 872 days, eccentricity of 0.494+/-0.081, and a minimum mass of 4.0M_J_. Due to aliasing we cannot rule out alternative solutions for the outer planet having a period of 220 days or 438 days. For HAT-P-45, at present there is not enough data to justify the additional free parameters included in a multi-planet model; in this case a single-planet solution is preferred, but the required jitter of 22.5+/-6.3m/s is relatively high for a star of this type. For HAT-P-46 the preferred solution includes a second planet having a period of 78 days and a minimum mass of 2.0M_J_, however the preference for this model over a single-planet model is not very strong. While substantial uncertainties remain as to the presence and/or properties of the outer planetary companions in these systems, the inner transiting planets are well characterized with measured properties that are fairly robust against changes in the assumed models for the outer planets. Continued radial velocity monitoring is necessary to fully characterize these three planetary systems, the properties of which may have important implications for understanding the formation of hot Jupiters.
2460. HAT-P-12 light curve
ID:
ivo://CDS.VizieR/J/ApJ/706/785
Title:
HAT-P-12 light curve
Short Name:
J/ApJ/706/785
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on the discovery of HAT-P-12b, a transiting extrasolar planet orbiting the moderately bright V~12.8 K4 dwarf GSC 03033-00706, with a period P=3.2130598+/-0.0000021d, transit epoch T_c_=2454419.19556+/-0.00020 (BJD), and transit duration 0.0974+/-0.0006d. The host star has a mass of 0.73+/-0.02M_{sun}_, radius of 0.70^+0.02^_-0.01_R_{sun}_, effective temperature 4650+/-60K, and metallicity [Fe/H]=-0.29+/-0.05. We find a slight correlation between the observed spectral line bisector spans and the radial velocity, so we consider, and rule out, various blend configurations including a blend with a background eclipsing binary, and hierarchical triple systems where the eclipsing body is a star or a planet. We conclude that a model consisting of a single star with a transiting planet best fits the observations, and show that a likely explanation for the apparent correlation is contamination from scattered moonlight. Based on this model, the planetary companion has a mass of 0.211+/-0.012M_J_ and radius of 0.959^+0.029^_-0.021_R_J_ yielding a mean density of 0.295+/-0.025g/cm^3^. Comparing these observations with recent theoretical models, we find that HAT-P-12b is consistent with a ~1-4.5Gyr, mildly irradiated, H/He-dominated planet with a core mass M_C_<~10M_{earth}_.