We report the first attempt to observe the secondary eclipse of a transiting extra-solar planet at radio wavelengths. We observed HD 189733 b with the Robert C. Byrd Green Bank Telescope of the NRAO over about 5.5 hours before, during and after secondary eclipse, at frequencies of 307 - 347 MHz. In this frequency range, we determine the 3-sigma upper limit to the flux density to be 81 mJy. The data are consistent with no eclipse or a marginal reduction in flux at the time of secondary eclipse in all subsets of our bandwidth; the strongest signal is an apparent eclipse at the 2-sigma level in the 335.2 - 339.3 MHz region. Our observed upper limit is close to theoretical predictions of the flux density of cyclotron-maser radiation from the planet.
We present the characterization of the transiting planet KELT-1b % ($R_p \simeq 1.15 R_J, M_p \simeq 27.23 M_J $) using data from the Transiting Exoplanet Survey Satellite (TESS). % during cycle $2$ and sector $17$. Our light curve model includes primary transit and secondary eclipse. Here, we model the systematic noise using Gaussian processes (GPs) and fit it to the data using the Markov Chain Monte Carlo (MCMC) method. Modelling of the TESS light curve returns a planet-to-star radius ratio, $p =$ $0.07652_{-0.00028}^{+0.00029}$ and a relatively large secondary eclipse depth of $388_{-13}^{+…
We report the discovery of a Neptune-size (R_p = 3.87 +/- 0.06 R_Earth) transiting circumbinary planet, Kepler-1661 b, found in the Kepler photometry. The planet has a period of ~175 days and its orbit precesses with a period of only 35 years. The precession causes the alignment of the orbital planes to vary, and the planet is in a transiting configuration only ~7% of the time as seen from Earth. As with several other Kepler circumbinary planets, Kepler-1661 b orbits close to the stability radius, and is near the (hot) edge of habitable zone. The planet orbits a single-lined, grazing eclipsing…
There are no field brown dwarf analogs with measured masses, radii, and luminosities, precluding our ability to connect the population of transiting brown dwarfs with measurable masses and radii and field brown dwarfs with measurable luminosities and atmospheric properties. LHS 6343 C, a weakly-irradiated brown dwarf transiting one member of an M+M binary in the Kepler field, provides the first opportunity to probe the atmosphere of a non-inflated brown dwarf with a measured mass and radius. Here, we analyze four Spitzer observations of secondary eclipses of LHS 6343 C behind LHS 6343 A. Joint…
We analyze all existing secondary eclipse time series spectroscopy of hot Jupiter HD189733b acquired with the now defunct Spitzer/IRS instrument. We describe the novel approaches we develop to remove the systematic effects and extract accurate secondary eclipse depths as a function of wavelength in order to construct the emission spectrum of the exoplanet. We compare our results to a previous study by Grillmair et al. that did not examine all data sets available to us. We are able to confirm the detection of a water feature near 6μm claimed by Grillmair et al. We compare the planetary emission…
We highlight a physical effect that is often not considered that impacts the calculation of model spectra of planets at secondary eclipse, affecting both emission and reflection spectra. The radius of the emitting surface of the planet is not merely one value measured from a transit light curve, but is itself a function of wavelength, yet it is not directly measurable. At high precision, a similar effect is well-known in transit "transmission spectroscopy" but this related effect also impacts emission and reflection. As is well-appreciated, the photospheric radius can vary across $\sim$4-8 atm…
Planet-Planet Eclipse and the Rossiter-McLaughlin Effect of a Multiple Transiting System: Joint Analysis of the Subaru Spectroscopy and the Kepler Photometry
[Abridged] We have only been able to comprehensively characterize the atmospheres of a handful of transiting planets, because most orbit faint stars. TESS will discover transiting planets orbiting the brightest stars, enabling, in principle, an atmospheric survey of 10^2 to 10^3 bright hot Jupiters and warm sub-Neptunes. Uniform observations of such a statistically significant sample would provide leverage to understand---and learn from---the diversity of short-period planets. We argue that the best way to maximize the scientific returns of TESS is with a follow-up space mission consisting of …
Planetary Construction Zones in Occultation: Discovery of an Extrasolar Ring System Transiting a Young Sun-like Star and Future Prospects for Detecting Eclipses by Circumsecondary and Circumplanetary Disks
We report the discovery of a new Kepler transiting circumbinary planet (CBP). This latest addition to the still-small family of CBPs defies the current trend of known short-period planets orbiting near the stability limit of binary stars. Unlike the previous discoveries, the planet revolving around the eclipsing binary system Kepler-1647 has a very long orbital period (~1100 days) and was at conjunction only twice during the Kepler mission lifetime. Due to the singular configuration of the system, Kepler-1647b is not only the longest-period transiting CBP at the time of writing, but also one o…
We analyze the phase curve of the short-period transiting hot Jupiter system WASP-19, which was observed by the Transiting Exoplanet Survey Satellite ($TESS$) in Sector 9. WASP-19 is one of only five transiting exoplanet systems with full-orbit phase curve measurements at both optical and infrared wavelengths. We measure a secondary eclipse depth of $470^{+130}_{-110}$ ppm and detect a strong atmospheric brightness modulation signal with a semi-amplitude of $319\pm51$ ppm. No significant offset is detected between the substellar point and the region of maximum brightness on the dayside. There …
While about a dozen transiting planets have been found in wide orbits around an inner, close stellar binary (so-called "P-type planets"), no planet has yet been detected orbiting only one star (a so-called "S-type planet") in an eclipsing binary. This is despite a large number of eclipsing binary systems discovered with the Kepler telescope. Here we propose a new detection method for these S-type planets, which uses a correlation between the stellar radial velocities (RVs), eclipse timing variations (ETVs), and eclipse duration variations (EDVs). We test the capability of this technique by sim…
We announce the discovery of the transiting hot Jupiter WASP-157b in a 3.95-d orbit around a V = 12.9 G2 main-sequence star. This moderately inflated planet has a Saturn-like density with a mass of $0.57 \pm 0.10$ M$_{\rm Jup}$ and a radius of $1.06 \pm 0.05$ R$_{\rm Jup}$. We do not detect any rotational or phase-curve modulations, nor the secondary eclipse, with conservative semi-amplitude upper limits of 250 and 20 ppm, respectively.
The WFIRST microlensing mission will measure precise light curves and relative parallaxes for millions of stars, giving it the potential to characterize short-period transiting planets all along the line of sight and into the galactic bulge. These light curves will enable the detection of more than 100,000 transiting planets whose host stars have measured distances. Although most of these planets cannot be followed up, several thousand hot Jupiters can be confirmed directly by detection of their secondary eclipses in the WFIRST data. Additionally, some systems of small planets may be confirmed…
In this work we present Spitzer 3.6 and 4.5 micron secondary eclipse observations of five new cool (<1200 K) transiting gas giant planets: HAT-P-19b, WASP-6b, WASP-10b, WASP-39b, and WASP-67b. We compare our measured eclipse depths to the predictions of a suite of atmosphere models and to eclipse depths for planets with previously published observations in order to constrain the temperature- and mass-dependent properties of gas giant planet atmospheres. We find that the dayside emission spectra of planets less massive than Jupiter require models with efficient circulation of energy to the nigh…
Detection limits for close eclipsing and transiting sub-stellar and planetary companions to white dwarfs in the WASP survey
我们使用WASP（广角行星搜索）调查的光度数据来探索探测日食和在白矮星附近轨道上的褐矮星、气体巨星和陆地伴星的凌日信号的可能性。我们进行了广泛的蒙特卡罗模拟，我们发现，高斯随机噪声WASP是敏感的同伴小到月球轨道$V\sim$ 12白矮星。对于较暗的恒星，WASP对越来越大的天体很敏感。我们的灵敏度下降的协变噪声结构的存在下的数据，然而地球大小的机构仍然很容易检测到相对较低的S/N数据。我们在WASP档案中的194颗白矮星样本中搜索了日食和凌日信号，但是没有发现伴星的证据。我们用我们的结果对这类系统的频率设定了暂定的上限。虽然我们只能对地球大小或更小的伴星的可能频率施加微弱的限制，但棕矮星和气体巨星（半径为$\simeq$ R $_{jup}$），周期为$\leq$ 0.2天的肯定是罕见的（$<10\%$）。更严格的限制要求更大的白矮星样本，更高的观测节奏和连续覆盖。与WASP观测的节奏相比，白矮星的日食和凌日的持续时间很短，这似乎是限制主序星行星凌日调查的主要因素之一。
A double planet system or planet binary undergoes eclipses that modify the reflective light curve. In the time domain, the eclipse events are fast and weak. This would make their signal difficult to find and recognize in the phase light curve, even for small inclinations when eclipses happen frequently. However, due to the quasiperiodic nature of the phenomenon, the Fourier transform of the direct reflection signal consists of a double sum of sharp peaks. These peaks can be resolved for large close binaries and sufficiently long observation times with a star coronagraph. Eclipses modulate the …
It is well-established that the magnitude of the incident stellar flux is the single most important factor in determining the day-night temperature gradients and atmospheric chemistries of short-period gas giant planets. However it is likely that other factors, such as planet-to-planet variations in atmospheric metallicity, C/O ratio, and cloud properties, also contribute to the observed diversity of infrared spectra for this population of planets. In this study we present new 3.6 and 4.5 micron secondary eclipse measurements for five transiting gas giant planets: HAT-P-5b, HAT-P-38b, WASP-7b,…
Observations of the star EPIC 220208795 (2MASS J01105556+0018507) reveal a single, deep and asymmetric eclipse, which we hypothesize is due to an eclipsing companion surrounded by a tilted and inclined opaque disk, similar to those seen around V928 Tau and EPIC 204376071. We aim to derive physical parameters of the disk and orbital parameters for the companion around the primary star. The modeling is carried out using a modified version of the python package pyPplusS, and optimization is done using emcee. The period analysis makes use of photometry from ground-based surveys, where we perform a…
WASP-12b is one of the most well-studied transiting exoplanets, as its highly-inflated radius and its 1.1 day orbit around a G0-type star make it an excellent target for atmospheric categorisation through observation during its secondary eclipse. We present two new secondary eclipse observations of WASP-12b, acquired a year apart with the Wide Field Camera on the Isaac Newton Telescope (INT) and the IO:O instrument on the Liverpool Telescope (LT). These observations were conducted in the $i^\prime$-band, a window expected to be dominated by TiO features if present in appreciable quantities in …
We describe the detection of water vapor in the atmosphere of the transiting hot Jupiter KELT-2Ab by treating the star-planet system as a spectroscopic binary with high-resolution, ground-based spectroscopy. We resolve the signal of the planet's motion with deep combined flux observations of the star and the planet. In total, six epochs of Keck NIRSPEC $L$-band observations were obtained, and the full data set was subjected to a cross correlation analysis with a grid of self-consistent atmospheric models. We measure a radial projection of the Keplerian velocity, $K_P$, of 148 $\pm$ 7 km s$^{-1…
Planetary rotation rates and obliquities provide information regarding the history of planet formation, but have not yet been measured for evolved extrasolar planets. Here we investigate the theoretical and observational perspective of the Rossiter-McLauglin effect during secondary eclipse (RMse) ingress and egress for transiting exoplanets. Near secondary eclipse, when the planet passes behind the parent star, the star sequentially obscures light from the approaching and receding parts of the rotating planetary surface. The temporal block of light emerging from the approaching (blue-shifted) …
Transiting exoplanets provide detailed access to their atmospheres, as the planet's signal can be effectively separated from that of its host star. For transiting exoplanets three fundamental atmospheric measurements are possible: transmission spectra - where atmospheric absorption features are detected across an exoplanets limb during transit, emission spectra - where the day-side average emission of the planet is detected during secondary eclipse events, and phase curves - where the spectral emission of the planet is mapped globally following the planet around its orbit. All of these techniq…
