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 + or - 0.000009 days, orbital eccentricity e = 0.342 + or - 0.006, transit epoch T sub(c) = 2454801.16943 + or - 0.00020 (BJD: barycentric Julian dates throughout the paper are calculated from Coordinated Universal Time (UTC)), and transit duration 0.1690 + or - 0.0009 days. HAT-P-17b has a mass of 0.534 + or - 0.018 M sub(J) and radius of 1.010 + or - 0.029 R sub(J) yielding a mean density of 0.64 + or - 0.05 g cm super(-3). This planet has a relatively low equilibrium temperature in the range 780-927 K, making it an attractive target for follow-up spectroscopic studies. The outer planet, HAT-P-17c, has a significantly longer orbital period P sub(2) = 1610 + or - 20 days and a minimum mass m sub(2) sin i sub(2) = 1.31 super(+0.18) sub(-0.15) M sub(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 + or - 0.04 M radius of 0.84 + or - 0.02 R, effective temperature 5246 + or - 80 K, and metallicity Fe/H = 0.00 + or - 0.08. HAT-P-17 is the second multi-planet system detected from ground-based transit surveys.
We report the discovery of HATS-5b, a transiting hot Saturn orbiting a G-type star, by the HATSouth survey. HATS-5b has a mass of M sub(P) approximately 0.24 M sub(J), radius of R sub(P) ...approximately 0.91 R sub(J), and transits its host star with a period of P approximately 4.7634 days. The radius of HATS-5b is consistent with both theoretical and empirical models. The host star has a V-band magnitude of 12.6, mass of 0.94 Modot, and radius of 0.87 Rodot. The relatively high scale height of HATS-5b and the bright, photometrically quiet host star make this planet a favorable target for future transmission spectroscopy follow-up observations. We reexamine the correlations in radius, equilibrium temperature, and metallicity of the close-in gas giants and find hot Jupiter-mass planets to exhibit the strongest dependence between radius and equilibrium temperature. We find no significant dependence in radius and metallicity for the close-in gas giant population.
HAT-P-42b and HAT-P-43b Boisse, I; Hartman, J D; Bakos, G A ...
Astronomy and astrophysics (Berlin),
10/2013, Letnik:
558
Journal Article
Recenzirano
Odprti dostop
Aims. We announce the discovery of two new transiting planets, and provide their accurate initial characterization. Methods. First identified from the HATNet wide-field photometric survey, these ...candidate transiting planets were then followed-up with a variety of photometric observations. Determining the planetary nature of the objects and characterizing the parameters of the systems were mainly done with the SOPHIE spectrograph at the 1.93 m telescope at OHP and the TRES spectrograph at the 1.5 m telescope at FLWO. Results. HAT-P-42b and HAT-P-43b are typical hot Jupiters on circular orbits around early-G/late-F main sequence host stars, with periods of 4.641878 + or - 0.000032 and 3.332687 + or - 0.000015 days, masses of 1.044 + or - 0.083 and 0.662 + or - 0.060 My, and radii of 1.280 + or - 0.153 and 1.28 super(+0.062) sub(-0.033RJ), respectively. These discoveries increase the sample of planets with measured mean densities, which are needed to constrain theories of planetary interiors and atmospheres. Moreover, their hosts are relatively bright (V < 13.5), which facilitates further follow-up studies.
Planets from the HATNet project Bakos, G. Á.; Hartman, J. D.; Torres, G. ...
EPJ Web of conferences,
2011, Letnik:
11
Journal Article
Recenzirano
Odprti dostop
We summarize the contribution of the HATNet project to extrasolar planet science, highlighting published planets (HAT-P-1b through HAT-P-26b). We also briefly discuss the operations, data analysis, ...candidate selection and confirmation procedures, and we summarize what HATNet provides to the exoplanet community with each discovery.
Wide-field surveys for transiting planets are well suited to searching diverse stellar populations, enabling a better understanding of the link between the properties of planets and their parent ...stars. We report the discovery of HAT-P-69 b (TOI 625.01) and HAT-P-70 b (TOI 624.01), two new hot Jupiters around A stars from the Hungarian-made Automated Telescope Network (HATNet) survey that have also been observed by the Transiting Exoplanet Survey Satellite. HAT-P-69 b has a mass of MJup and a radius of RJup and resides in a prograde 4.79 day orbit. HAT-P-70 b has a radius of RJup and a mass constraint of MJup and resides in a retrograde 2.74 day orbit. We use the confirmation of these planets around relatively massive stars as an opportunity to explore the occurrence rate of hot Jupiters as a function of stellar mass. We define a sample of 47,126 main-sequence stars brighter than Tmag = 10 that yields 31 giant planet candidates, including 18 confirmed planets, 3 candidates, and 10 false positives. We find a net hot Jupiter occurrence rate of 0.41 0.10% within this sample, consistent with the rate measured by Kepler for FGK stars. When divided into stellar mass bins, we find the occurrence rate to be 0.71 0.31% for G stars, 0.43 0.15% for F stars, and 0.26 0.11% for A stars. Thus, at this point, we cannot discern any statistically significant trend in the occurrence of hot Jupiters with stellar mass.
ABSTRACT We present the discovery of the transiting exoplanets HAT-P-65b and HAT-P-66b, with orbital periods of and days, masses of and , and inflated radii of and , respectively. They orbit ...moderately bright ( and ) stars of mass and . The stars are at the main-sequence turnoff. While it is well known that the radii of close-in giant planets are correlated with their equilibrium temperatures, whether or not the radii of planets increase in time as their hosts evolve and become more luminous is an open question. Looking at the broader sample of well-characterized close-in transiting giant planets, we find that there is a statistically significant correlation between planetary radii and the fractional ages of their host stars, with a false-alarm probability of only 0.0041%. We find that the correlation between the radii of planets and the fractional ages of their hosts is fully explained by the known correlation between planetary radii and their present-day equilibrium temperatures; however, if the zero-age main-sequence equilibrium temperature is used in place of the present-day equilibrium temperature, then a correlation with age must also be included to explain the planetary radii. This suggests that, after contracting during the pre-main-sequence, close-in giant planets are reinflated over time due to the increasing level of irradiation received from their host stars. Prior theoretical work indicates that such a dynamic response to irradiation requires a significant fraction of the incident energy to be deposited deep within the planetary interiors.
We report the discovery of HAT-P-67b, which is a hot-Saturn transiting a rapidly rotating F-subgiant. HAT-P-67b has a radius of , and orbites a , host star in a ∼4.81 day period orbit. We place an ...upper limit on the mass of the planet via radial velocity measurements to be , and a lower limit of by limitations on Roche lobe overflow. Despite being a subgiant, the host star still exhibits relatively rapid rotation, with a projected rotational velocity of , which makes it difficult to precisely determine the mass of the planet using radial velocities. We validated HAT-P-67b via two Doppler tomographic detections of the planetary transit, which eliminate potential eclipsing binary blend scenarios. The Doppler tomographic observations also confirm that HAT-P-67b has an orbit that is aligned to within 12°, in projection, with the spin of its host star. HAT-P-67b receives strong UV irradiation and is among one of the lowest density planets known, which makes it a good candidate for future UV transit observations in the search for an extended hydrogen exosphere.
ABSTRACT We report the discovery of HAT-P-56b by the HATNet survey, an inflated hot Jupiter transiting a bright F-type star in Field 0 of NASA's K2 mission. We combine ground-based discovery and ...follow-up light curves with high precision photometry from K2, as well as ground-based radial velocities from the Tillinghast Reflector Echelle Spectrograph on the Fred Lawrence Whipple Observatory 1.5 m telescope to determine the physical properties of this system. HAT-P-56b has a mass of 2.18 , radius of 1.47 , and transits its host star on a near-grazing orbit with a period of 2.7908 day. The radius of HAT-P-56b is among the largest known for a planet with . The host star has a V-band magnitude of 10.9, mass of 1.30 , and radius of 1.43 . The periodogram of the K2 light curve suggests that the star is a γ Dor variable. HAT-P-56b is an example of a ground-based discovery of a transiting planet, where space-based observations greatly improve the confidence in the confirmation of its planetary nature, and also improve the accuracy of the planetary parameters.
ABSTRACT We report the discovery and characterization of four transiting exoplanets by the HATNet survey. The planet HAT-P-50b has a mass of and radius of , and orbits a bright ( mag) , star every ...days. The planet HAT-P-51b has a mass of and radius of , and orbits a mag, , star with a period of days. The planet HAT-P-52b has a mass of and radius of , and orbits a mag, , star with a period of days. The planet HAT-P-53b has a mass of and radius of , and orbits a mag, , star with a period of days. All four planets are consistent with having circular orbits and have masses and radii measured to better than 10% precision. The low stellar jitter and favorable / ratio for HAT-P-51 make it a promising target for measuring the Rossiter-McLaughlin effect for a Saturn-mass planet.
ABSTRACT We present the discovery of HAT-P-57b, a P = 2.4653 day transiting planet around a mag, K main sequence A8V star with a projected rotation velocity of . We measure the radius of the planet ...to be and, based on RV observations, place a 95% confidence upper limit on its mass of . Based on theoretical stellar evolution models, the host star has a mass and radius of and , respectively. Spectroscopic observations made with Keck-I/HIRES during a partial transit event show the Doppler shadow of HAT-P-57b moving across the average spectral line profile of HAT-P-57, confirming the object as a planetary system. We use these observations, together with analytic formulae that we derive for the line profile distortions, to determine the projected angle between the spin axis of HAT-P-57 and the orbital axis of HAT-P-57b. The data permit two possible solutions, with or at 95% confidence, and with relative probabilities for the two modes of 26% and 74%, respectively. Adaptive optics imaging with MMT/Clio2 reveals an object located from HAT-P-57 consisting of two point sources separated in turn from each other by The H- and -band magnitudes of the companion stars are consistent with their being physically associated with HAT-P-57, in which case they are stars of mass and . HAT-P-57 is the most rapidly rotating star, and only the fourth main sequence A star, known to host a transiting planet.
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