- ID:
- ivo://CDS.VizieR/J/MNRAS/468/3907
- Title:
- HAT-P-18b wavelength binned light curves
- Short Name:
- J/MNRAS/468/3907
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have performed ground-based transmission spectroscopy of the hot Jupiter HAT-P-18b using the ACAM instrument on the William Herschel Telescope (WHT). Differential spectroscopy over an entire night was carried out at a resolution of R~400 using a nearby comparison star. We detect a bluewards slope extending across our optical transmission spectrum which runs from 4750{AA} to 9250{AA}. The slope is consistent with Rayleigh scattering at the equilibrium temperature of the planet (852K). We do not detect enhanced sodium absorption, which indicates a high altitude haze is masking the feature and giving rise to the Rayleigh slope. This is only the second discovery of a Rayleigh scattering slope in a hot Jupiter atmosphere from the ground, and our study illustrates how ground-based observations can provide transmission spectra with precision comparable to the Hubble Space Telescope (HST).
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Search Results
- 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.
- 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.
- 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.
- 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.
- 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_.
- 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.
408. 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}_.
- ID:
- ivo://CDS.VizieR/J/ApJ/707/446
- Title:
- HAT-P-13 photometry follow-up
- Short Name:
- J/ApJ/707/446
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the discovery of a planetary system with a close-in transiting hot Jupiter on a near circular orbit and a massive outer planet on a highly eccentric orbit. The inner planet, HAT-P-13b, transits the bright V=10.622 G4 dwarf star GSC 3416-00543 every P=2.916260+/-0.000010 days, with transit epoch T_c_=2454779.92979+/-0.00038 (BJD) and duration 0.1345+/-0.0017 days. The outer planet HAT-P-13c orbits the star every P_2_=428.5+/-3.0 days with a nominal transit center (assuming zero impact parameter) of T_2c_=2454870.4+/-1.8 (BJD) or time of periastron passage T_2,peri_=2454890.05+/-0.48 (BJD). Transits of the outer planet have not been observed, and may not be present. The host star has a mass of 1.22^+0.05^_-0.10_M_{sun}_, radius of 1.56+/-0.08R_{sun}_, effective temperature of 5653+/-90K, and is rather metal-rich with [Fe/H]=+0.41+/-0.08.
- ID:
- ivo://CDS.VizieR/J/ApJ/749/134
- Title:
- HAT-P-17 radial velocities and light curves
- Short Name:
- J/ApJ/749/134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HAT-P-17b,c, a multi-planet system with an inner transiting planet in a short-period, eccentric orbit and an outer planet in a 4.4 yr, nearly circular orbit. The inner planet, HAT-P-17b, transits the bright V=10.54 early K dwarf star GSC 2717-00417, with an orbital period P=10.338523+/-0.000009 days, orbital eccentricity e=0.342+/-0.006, transit epoch T_c_=2454801.16943+/-0.00020 (BJD: barycentric Julian dates throughout the paper are calculated from Coordinated Universal Time (UTC)), and transit duration 0.1690+/-0.0009 days. HAT-P-17b has a mass of 0.534+/-0.018M_J_ and radius of 1.010+/-0.029R_J_ yielding a mean density of 0.64+/-0.05g/cm3. This planet has a relatively low equilibrium temperature in the range 780-927K, making it an attractive target for follow-up spectroscopic studies. The outer planet, HAT-P-17c, has a significantly longer orbital period P_2_=1610+/-20d and a minimum mass m_2_sini_2_=1.31^+0.18^_-0.15_M_J_. The orbital inclination of HAT-P-17c is unknown as transits have not been observed and may not be present. The host star has a mass of 0.86+/-0.04M_{sun}_, radius of 0.84+/-0.02R_{sun}_, effective temperature 5246+/-80K, and metallicity [Fe/H]=0.00+/-0.08. HAT-P-17 is the second multi-planet system detected from ground-based transit surveys.
