We present design considerations for a ground-based survey for transiting exoplanets around L and T dwarfs, spectral classes that have yet to be thoroughly probed for planets. We simulate photometry for L and T targets with a variety of red-optical and near-infrared detectors, and compare the scatter in the photometry to anticipated transit depths. Based on these results, we recommend the use of a low-dark-current detector with H-band NIR photometric capabilities. We then investigate the potential for performing a survey for Earth-sized planets for a variety of telescope sizes. We simulate planetary systems around a set of spectroscopically confirmed L and T dwarfs using measured M dwarf planet occurrence rates from $\textit{Kepler}$, and simulate their observation in surveys ranging in duration from 120 to 600 nights, randomly discarding 30% of nights to simulate weather losses. We find that an efficient survey design uses a 2-meter-class telescope with a NIR instrument and 360-480 observing nights, observing multiple L and T targets each night with a dithering strategy. Surveys conducted in such a manner have over an 80% chance of detecting at least one planet, and detect around 2 planets, on average. The number of expected detections depends on the true planet occurrence rate, however, which may in fact be higher for L and T dwarfs than for M dwarfs.
This paper reviews the basic technical characteristics of the ground-based photometric searches for transiting planets, and discusses a possible observational selection effect. I suggest that additional photometric observations of the already observed fields might discover new transiting planets with periods around 4-6 days. The set of known transiting planets support the intriguing correlation between the planetary mass and the orbital period suggested already in 2005.
More than a decade after astronomers realized that disrupted planetary material likely pollutes the surfaces of many white dwarf stars, the discovery of transiting debris orbiting the white dwarf WD 1145+017 has opened the door to new explorations of this process. We describe the observational evidence for transiting planetary material and the current theoretical understanding (and in some cases lack thereof) of the phenomenon.
We report the discovery of a transiting, gas giant circumbinary planet orbiting the eclipsing binary KIC 4862625 and describe our independent discovery of the two transiting planets orbiting Kepler-47 (Orosz et al. 2012). We describe a simple and semi-automated procedure for identifying individual transits in light curves and present our follow-up measurements of the two circumbinary systems. For the KIC 4862625 system, the 0.52+/-0.018 RJup radius planet revolves every ~138 days and occults the 1.47+/-0.08 MSun, 1.7 +/-0.06 RSun F8 IV primary star producing aperiodic transits of variable dura…
We outline a photometric method for detecting the presence of a non-transiting short-period giant planet in a planetary system harboring one or more longer period transiting planets. Within a prospective system of the type that we consider, a hot Jupiter on an interior orbit inclined to the line-of-sight signals its presence through approximately sinusoidal full-phase photometric variations in the stellar light curve, correlated with astrometrically induced transit timing variations for exterior transiting planets. Systems containing a hot Jupiter along with a low-mass outer planet or planets …
We present spectroscopic measurements of the Rossiter-McLaughlin effect for the planet b of Kepler-9 multi-transiting planet system. The resulting sky-projected spin-orbit angle is $λ=-13^{\circ} \pm 16^{\circ}$, which favors an aligned system and strongly disfavors highly misaligned, polar, and retrograde orbits. Including Kepler-9, there are now a total of 4 Rossiter-McLaughlin effect measurements for multiplanet systems, all of which are consistent with spin-orbit alignment.
Previous work has demonstrated that the Large Synoptic Survey Telescope (LSST) has the capability to detect transiting planets around main sequence stars in relatively short ($<$ 20 days) periods and using standard algorithms for transit detection and period recoverability. In this paper, we demonstrate how an algorithm proposed in Tingley (2011) can be used for detecting transiting planets around white dwarfs with LSST. This application offsets the very short transit duration with the large change in magnitude caused by a transit of a white dwarf so that only a few points in transit are neede…
The outer architectures of Kepler's compact systems of multiple transiting planets remain poorly constrained and few of these systems have lower bounds on the orbital distance of any massive outer planets. We infer a minimum orbital distance and upper limits on the inclination of a hypothetical Jovian-mass planet orbiting exterior to the six transiting planets at Kepler-11. Our constraints are derived from dynamical models together with observations provided by the Kepler mission. Firstly, the lack of transit timing variations (TTV) in the outermost transiting planet Kepler-11 g imply that the…
Each transiting planet discovered is characterized by 7 measurable quantities, that may or may not be linked together (planet mass, radius, orbital period, and star mass, radius, effective temperature, and metallicity). Correlations between planet mass and period, surface gravity and period, planet radius and star temperature have been previously observed among the known transiting giant planets. Two classes of planets have been previously identified based on their Safronov number. We use the CoRoTlux code to compare simulated events to the sample of discovered planets and test the statistical…
Among other things, studies of the formation and evolution of planetary systems currently draw on two important observational resources: the precise characterization available for planets that transit their parent stars and the frequency and nature of systems with multiple planets. Thus far, the study of transiting exoplanets has focused almost exclusively on systems with only one planet, except for considering the influence of additional planets on the transit light curve, mostly through transit timing variations (TTVs). This work considers systems where multiple planets are seen to transit t…
Debris discs are known to exist around many planet-host stars, but no debris dust has been found so far in systems with transiting planets. Using publicly available catalogues, we searched for infrared excesses in such systems. In the recently published Wide-Field Infrared Survey Explorer (WISE) catalogue, we found 52 stars with transiting planets. Two systems with one transiting "hot Jupiter" each, TrES-2 and XO-5, exhibit small excesses both at 12 and 22 microns at a > 3 sigma level. Provided that one or both of these detections are real, the frequency of warm excesses in systems with transi…
The phenomenon of microlensing has successfully been used to detect extrasolar planets. By observing characteristic, rare deviations in the gravitational microlensing light curve one can discover that a lens is a star--planet system. In this paper we consider an opposite case where the lens is a single star and the source has a transiting planetary companion. We have studied the light curve of a source star with transiting companion magnified during microlensing event. Our model shows that in dense stellar fields, in which blending is significant, the light drop generated by transits is greate…
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…
Tidal dissipation within a short-period transiting extrasolar planet perturbed by a companion object can drive orbital evolution of the system to a so-called tidal fixed point, in which the apsidal lines of the transiting planet and its perturber are aligned, and for which variations in the orbital eccentricities of both planet and perturber are damped out. Significant contributions to the apsidal precession rate are made by the secular planet-planet interaction, by general relativity, and by the gravitational quadropole fields created by the transiting planet's tidal and rotational distortion…
We present new transit observations of the transiting exoplanet TrES-3b obtained in the range 2009 -- 2011 at several observatories. The orbital parameters of the system were redetermined and the new linear ephemeris was calculated. We performed numerical simulations for studying the long-term stability of orbits.
A global Markov Chain Monte Carlo analysis of published eclipse photometry and radial velocities is presented for the transiting planet HD 80606b. Despite the lack of a complete transit light curve, the size of the planet is measured with a good level of precision (R_p = 1.04 +0.05-0.09 R_Jup), while the orbital parameters are refined. This global analysis reveals that the orbital axis of the planet is significatively inclined relative to the spin axis of the host star (Beta = -59 +18-28 deg), providing a compelling evidence that HD 80606b owes its peculiar orbit to the Kozai migration mechani…
Context. The photometric signal we receive from a star hosting a planet is modulated by the variation of the planet signal with its orbital phase. Such phase variations are observed for transiting hot Jupiters with current instrumentation, and have also been measured for one transiting terrestrial planet (Kepler 10 b) and one non-transiting gas giant (Ups A b). Future telescopes (JWST and EChO) will have the capability to measure thermal phase curves of exoplanets including hot rocky planets in transiting and non-transiting configurations, and at different wavelengths. Short-period planets wit…
The derived physical properties of the known transiting extrasolar planetary systems come from a variety of sources, and are calculated using a range of different methods so are not always directly comparable. I present a catalogue of the physical properties of 58 transiting extrasolar planet and brown dwarf systems which have been measured using homogeneous methods, resulting in quantities which are internally consistent and well-suited to detailed statistical study. The main results for each object, plus a critical compilation of literature values for all known systems, have been placed in a…
M-dwarfs are known to commonly host high-multiplicity planetary systems. Therefore M-dwarf planetary systems with a known transiting planet are expected to contain additional small planets ($r_p \le 4$ R$_{\oplus}$, $m_p \lesssim 20$ M$_{\oplus}$) that are not seen in transit. In this study we investigate the effort required to detect such planets using precision velocimetry around the sizable subset of M-dwarfs which are slowly rotating ($P_{\mathrm{rot}} \gtrsim 40$ days) and hence more likely to be inactive. We focus on the test case of GJ 1132. Specifically, we perform a suite of Monte-Car…
We have bandmerged candidate transiting planetary systems (from the Kepler satellite) and confirmed transiting planetary systems (from the literature) with the recent Wide-field Infrared Survey Explorer (WISE) preliminary release catalog. We have found 13 stars showing infrared excesses at either 12 and/or 22 microns. Without longer wavelength observations it is not possible to conclusively determine the nature of the excesses, although we argue that they are likely due to debris disks around the stars. If confirmed, our sample ~ doubles the number of currently known warm excess disks around o…
The KELT project was originally designed as a small-aperture, wide-field photometric survey that would be optimally sensitive to planets transiting bright (V~8-10) stars. This magnitude range corresponded to the gap between the faint magnitude limit where radial velocity surveys were complete, and the bright magnitude limit for transiting planet hosts routinely found by dedicated ground-based transit surveys. Malmquist bias and other factors have also led the KELT survey to focus on discovering planets transiting relatively hot host stars as well. To date, the survey has discovered 22 transiti…
We revisit the tidal stability of extrasolar systems harboring a transiting planet and demonstrate that, independently of any tidal model, none but one (HAT-P-2b) of these planets has a tidal equilibrium state, which implies ultimately a collision of these objects with their host star. Consequently, conventional circularization and synchronization timescales cannot be defined because the corresponding states do not represent the endpoint of the tidal evolution. Using numerical simulations of the coupled tidal equations for the spin and orbital parameters of each transiting planetary system, we…
When an extrasolar planet passes in front of its star (transits), its radius can be measured from the decrease in starlight and its orbital period from the time between transits. Multiple planets transiting the same star reveal more: period ratios determine stability and dynamics, mutual gravitational interactions reflect planet masses and orbital shapes, and the fraction of transiting planets observed as multiples has implications for the planarity of planetary systems. But few stars have more than one known transiting planet, and none has more than three. Here we report Kepler spacecraft obs…
We report the discovery of the transiting extrasolar planet HAT-P-49b. The planet transits the bright (V = 10.3) slightly evolved F-star HD 340099 with a mass of 1.54M_S and a radius of 1.83 R_S. HAT-P-49b is orbiting one of the 25 brightest stars to host a transiting planet which makes this a favorable candidate for detailed follow-up. This system is an especially strong target for Rossiter- McLaughlin follow-up due to the fast rotation of the host star, 16 km/s. The planetary companion has a period of 2.6915 d, mass of 1.73 M_J and radius of 1.41 R_J. The planetary characteristics are consis…
We report the discovery by the CoRoT satellite of a new transiting giant planet in a 2.83 days orbit about a V=15.5 solar analog star (M_* = 1.08 +- 0.08 M_sun, R_* = 1.1 +- 0.1 R_sun, T_eff = 5675 +- 80 K). This new planet, CoRoT-12b, has a mass of 0.92 +- 0.07 M_Jup and a radius of 1.44 +- 0.13 R_Jup. Its low density can be explained by standard models for irradiated planets.
We present the discovery of three small planets transiting K2-136 (LP 358 348, EPIC 247589423), a late K dwarf in the Hyades. The planets have orbital periods of $7.9757 \pm 0.0011$, $17.30681^{+0.00034}_{-0.00036}$, and $25.5715^{+0.0038}_{-0.0040}$ days, and radii of $1.05 \pm 0.16$, $3.14 \pm 0.36$, and $1.55^{+0.24}_{-0.21}$ $R_\oplus$, respectively. With an age of 600-800 Myr, these planets are some of the smallest and youngest transiting planets known. Due to the relatively bright (J=9.1) host star, the planets are compelling targets for future characterization via radial velocity mass m…
Host star metallicities have been used to infer observational constraints on planet formation throughout the history of the exoplanet field. The giant planet metallicity correlation has now been widely accepted, but questions remain as to whether the metallicity correlation extends to the small terrestrial-sized planets. Here, we report metallicities for a sample of 518 stars in the Kepler field that have no detected transiting planets and compare their metallicity distribution to a sample of stars that hosts small planets (Rp < 1.7 R_Earth). Importantly, both samples have been analyzed in a h…
The discovery of multiple transiting planetary systems offers new possibilities for characterising exoplanets and understanding their formation. The Kepler-9 system contains two Saturn-mass planets, Kepler-9b and 9c. Using evolution models of gas giants that reproduce the sizes of known transiting planets and accounting for all sources of uncertainties, we show that Kepler-9b (respectively 9c) contains $45^{+17}_{-12}$\,\mearth\ (resp. $31^{+13}_{-10}$\,\mearth) of hydrogen and helium and $35^{+10}_{-15}$\,\mearth (resp. $24^{+10}_{-12}$\,\mearth) of heavy elements. More accurate constraints a…
Planets on eccentric orbits have a higher geometric probability of transiting their host star. By application of Bayes' theorem, we reverse this logic to show that the eccentricity distribution of transiting planets is positively biased. Adopting the flexible Beta distribution as the underlying prior for eccentricity, we derive the marginalized transit probability as well as the a-priori joint probability distribution of eccentricity and argument of periastron, given that a planet is known to transit. These results allow to demonstrate that most planet occurrence rate calculations using Kepler…
We report a sensitive search for meter-wavelength emission at 150 MHz from two prominent transiting extrasolar planets, HD189733b and HD209458b. To distinguish any planetary emission from possible stellar or background contributions, we monitored these systems just prior to, during, and after the planet's eclipse behind the host star. No emission was detected from HD209458b with a 3-sigma upper limit of 3.6 mJy. For HD189733b we obtain a 3-sigma upper limit of 2.1 mJy and a marginal 2.7-sigma detection of about 1.9+/-0.7 mJy from a direction just 13" from the star's coordinates (i.e., within t…
The Large Synoptic Survey Telescope (LSST) will photometrically monitor approximately 1 billion stars for ten years. The resulting light curves can be used to detect transiting exoplanets. In particular, as demonstrated by Lund et al. (2015), LSST will probe stellar populations currently undersampled in most exoplanet transit surveys, including out to extragalactic distances. In this paper we test the efficiency of the box-fitting least-squares (BLS) algorithm for accurately recovering the periods of transiting exoplanets using simulated LSST data. We model planets with a range of radii orbiti…
The optical, full-phase photometric variations of a short-period planet provide a unique view of the planet's atmospheric composition and dynamics. The number of planets with optical phase curve detections, however, is currently too small to study them as an aggregate population, motivating an extension of the search to non-transiting planets. Here we present an algorithm for the detection of non-transiting, short-period giant planets in the Kepler field. The procedure uses the phase curves themselves as evidence for the planets' existence. We employ a supervised learning algorithm to recogniz…
[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 …
The CoRoT satellite exoplanetary team announces its sixth transiting planet in this paper. We describe and discuss the satellite observations as well as the complementary ground-based observations - photometric and spectroscopic - carried out to assess the planetary nature of the object and determine its specific physical parameters. The discovery reported here is a `hot Jupiter' planet in an 8.9d orbit, 18 stellar radii, or 0.08 AU, away from its primary star, which is a solar-type star (F9V) with an estimated age of 3.0 Gyr. The planet mass is close to 3 times that of Jupiter. The star has a…
We present eight new light curves of the transiting extra-solar planet HAT-P-25b obtained from 2013 to 2016 with three telescopes at two observatories. We use the new light curves, along with recent literature material, to estimate the physical and orbital parameters of the transiting planet. Specifically, we determine the mid-transit times (T$_{C}$) and update the linear ephemeris, T$_{C[0]}$=2456418.80996$\pm$0.00025 [$\mathrm{BJD}_\mathrm{TDB}$] and P=3.65281572$\pm$0.00000095 days. We carry out a search for transit timing variations (TTVs), and find no significant TTV signal at the $ΔT=$80…
We present the discovery of a candidate multiply-transiting system, the first one found in the CoRoT mission. Two transit-like features with periods of 5.11 and 11.76d are detected in the CoRoT light curve, around a main sequence K1V star of r=15.1. If the features are due to transiting planets around the same star, these would correspond to objects of 3.7$\pm$0.4 and 5.0$\pm$0.5 R_earth respectively. Several radial velocities serve to provide an upper limit of 5.7 M_earth for the 5.11~d signal, and to tentatively measure a mass of 28$^{+11}_{-11}$ M_earth for the object transiting with a 11.7…
We present two new planetary systems found around cool dwarf stars with data from the K2 mission. The first system was found in K2-239 (EPIC 248545986), char- acterized in this work as M3.0V and observed in the 14th campaign of K2. It consists of three Earth-size transiting planets with radii of 1.1, 1.0 and 1.1 R Earth, showing a compact configuration with orbital periods of 5.24, 7.78 and 10.1 days, close to 2:3:4 resonance. The second was found in K2-240 (EPIC 249801827), characterized in this work as M0.5V and observed in the 15th campaign. It consists of two transiting super-Earths with r…
We report the discovery of HATS-1b, a transiting extrasolar planet orbiting the moderately bright V=12.05 G dwarf star GSC 6652-00186, and the first planet discovered by HATSouth, a global network of autonomous wide-field telescopes. HATS-1b has a period P~3.4465 d, mass Mp~1.86MJ, and radius Rp~1.30RJ. The host star has a mass of 0.99Msun, and radius of 1.04Rsun. The discovery light curve of HATS-1b has near continuous coverage over several multi-day periods, demonstrating the power of using a global network of telescopes to discover transiting planets.
The stellar obliquity of a transiting planetary system can be constrained by combining measurements of the star's rotation period, radius, and projected rotational velocity. Here we present a hierarchical Bayesian technique for recovering the obliquity distribution of a population of transiting planetary systems, and apply it to a sample of 70 Kepler Objects of Interest. With ~95% confidence we find that the obliquities of stars with only a single detected transiting planet are systematically larger than those with multiple detected transiting planets. This suggests that a substantial fraction…
We report the discovery of the low-density, transiting giant planet WASP-31b. The planet is 0.48 Jupiter masses and 1.55 Jupiter radii. It is in a 3.4-day orbit around a metal-poor, late-F-type, V = 11.7 dwarf star, which is a member of a common proper motion pair. In terms of its low density, WASP-31b is second only to WASP-17b, which is a more highly irradiated planet of similar mass.
We report the discovery of WASP-8, a transiting planet of 2.25+-0.08 M_Jup on a strongly inclined eccentric 8.15-day orbit, moving in a retrograde direction to the rotation of its late-G host star. Evidence is found that the star is in a multiple stellar system with two other companions. The dynamical complexity of the system indicates that it may have experienced secular interactions such as the Kozai mechanism or a formation that differs from the ``classical" disc-migration theory.
Detection of transiting exoplanets around young stars is more difficult than for older systems due to increased stellar variability. Nine young open cluster planets have been found in the K2 data, but no single analysis pipeline identified all planets. We have developed a transit search pipeline for young stars which uses a transit-shaped notch and quadratic continuum in a 12 or 24\,hour window to fit both the stellar variability and the presence of a transit. In addition, for the most rapid rotators (P$_\mathrm{rot}<2$\,days) we model the variability using a linear combination of observed rot…
The direct detection of new extrasolar planets from high-precision photometry data is commonly based on the observation of the transit signal of the planet as it passes in front of its star. Close-in planets, however, leave additional imprints in the light curve even if they do not transit. These are the so-called phase curve variations that include ellipsoidal, reflection and beaming effects. In Millholland & Laughlin (2017), the authors scrutinized the Kepler database looking for these phase variations from non-transiting planets. They found 60 candidates whose signals were compatible with p…
We report a sensitive search for meter-wavelength emission at 244 and 614 MHz from HD189733b, the nearest known extrasolar transiting planet of `hot-Jupiter' type. To discriminate any planetary emission from possible stellar or background contributions, we observed the system for 7.7 hours encompassing the planet's eclipse behind the host star. These GMRT observations provide very low (3 sigma) upper limits of 2 mJy at 244 MHz and 160 micro-Jy at 614 MHz. These limits are, respectively, about 40 and 500 times deeper than those reported recently at a nearby frequency of 340 MHz. Possible explan…
We present the confirmation and characterisation of GJ 3473 b (G 50--16, TOI-488.01), a hot Earth-sized planet orbiting an M4 dwarf star, whose transiting signal ($P=1.1980035\pm0.0000018\mathrm{\,d}$) was first detected by the Transiting Exoplanet Survey Satellite (TESS). Through a joint modelling of follow-up radial velocity observations with CARMENES, IRD, and HARPS together with extensive ground-based photometric follow-up observations with LCOGT, MuSCAT, and MuSCAT2, we determined a precise planetary mass, $M_b = 1.86\pm0.30\,\mathrm{M_\oplus},$ and radius, $R_b = {1.264\pm0.050}\,\mathrm…
We report on the detection of three transiting small planets around the low-mass star LP 358-499 (K2-133), using photometric data from the Kepler-K2 mission. Using multiband photometry, we determine the host star to be an early M dwarf with an age likely older than a Gigayear. The three detected planets K2-133 b, c, and d have orbital periods of ca. 3, 4.9 and 11 days and transit depths of ca. 700, 1000 and 2000 ppm, respectively. We also report a planetary candidate in the system (EPIC 247887989.01) with a period of 26.6 days and a depth of ca. 1000 ppm, which may be at the inner edge of the …
We present an improved version of SOAP (Boisse et al. 2012) named "SOAP-T", which can generate the radial velocity variations and light-curves for systems consisting of a rotating spotted star with a transiting planet. This tool can be used to study the anomalies inside transit light-curves and the Rossiter-McLaughlin effect, to better constrain the orbital configuration and properties of planetary systems and active zones of their host stars. Tests of the code are presented to illustrate its performance and to validate its capability when compared with analytical models and real data. Finally…
Recently K2 and TESS have discovered transiting planets with radii between $\sim$ 5-10 R$_\oplus$ around stars with ages $<100$ Myr. These young planets are likely to be the progenitors of the ubiquitous super-earths/sub-neptunes, that are well studied around stars with ages $\gtrsim 1$ Gyr. The formation and early evolution of super-earths/sub-neptunes are poorly understood. Various planetary origin scenarios predict a wide range of possible formation entropies. We show how the formation entropies of young ($\sim$20-60 Myr), highly irradiated planets can be constrained if their mass, radius a…
We revisit the discovery and implications of the first candidate systems to contain multiple transiting exoplanets. These systems were discovered using data from the Kepler space telescope. The initial paper, presenting five systems (Steffen et al. 2010), was posted online at the time the project released the first catalog of Kepler planet candidates. The first extensive analysis of the observed population of multis was presented in a follow-up paper published the following year (Lissauer et al. 2011a). Multiply-transiting systems allow us to answer a variety of important questions related to …
A planet's orbital orientation relative to an observer's line of sight determines the chord length for a transiting planet, i.e., the projected distance a transiting planet travels across the stellar disc. For a given circular orbit, the chord length determines the transit duration. Changes in the orbital inclination, the direction of the ascending node, or both, can alter this chord length and thus result in transit duration variations (TDVs). Variation of the full orbital inclination vector can even lead to de-transiting or newly transiting planets for a system. We use Laplace-Lagrange secul…
We present results from a search for additional transiting planets in 24 systems already known to contain a transiting planet. We model the transits due to the known planet in each system and subtract these models from lightcurves obtained with the SuperWASP survey instruments. These residual lightcurves are then searched for evidence of additional periodic transit events. Although we do not find any evidence for additional planets in any of the planetary systems studied, we are able to characterise our ability to find such planets by means of Monte Carlo simulations. Artificially generated tr…
NASA's Kepler Space Telescope has successfully discovered thousands of exoplanet candidates using the transit method, including hundreds of stars with multiple transiting planets. In order to estimate the frequency of these valuable systems, it is essential to account for the unique geometric probabilities of detecting multiple transiting extrasolar planets around the same parent star. In order to improve on previous studies that used numerical methods, we have constructed an efficient, semi-analytical algorithm called CORBITS which, given a collection of conjectured exoplanets orbiting a star…
Two transiting planets have been identified orbiting K2 target EPIC 220674823. One object is an ultra-short-period planet (USP) with a period of just 0.57 days (13.7 hours), while the other has a period of 13.3 days. Both planets are small, with the former having a radius of R_p1=1.5 R_E and the latter R_p2=2.5 R_E. Follow-up observations, including radial velocity (with uncertainties of 110 m/s) and high-resolution adaptive optics imagery, show no signs of stellar companions. EPIC 220674823 is the 12th confirmed or validated planetary system in which an ultra-short-period planet (i.e., having…
The Large Synoptic Survey Telescope (LSST) will generate light curves for approximately 1 billion stars. Our previous work has demonstrated that, by the end of the LSST 10 year mission, large numbers of transiting exoplanetary systems could be recovered using the LSST "deep drilling" cadence. Here we extend our previous work to examine how the recoverability of transiting planets over a range of orbital periods and radii evolves per year of LSST operation. As specific example systems we consider hot Jupiters orbiting solar-type stars and hot Neptunes orbiting K-Dwarfs at distances from Earth o…
There have been numerous reports of anomalies during transits of the planet TrES-1b. Recently, Rabus and coworkers' analysis of HST observations lead them to claim brightening anomalies during transit might be caused by either a second transiting planet or a cool starspot. Observations of two consecutive transits are presented here from the University of Arizona's 61-inch Kuiper Telescope on May 12 and May 15, 2008 UT. A 5.4 +/- 1.7 mmag (0.54 +/- 0.17%) brightening anomaly was detected during the first half of the transit on May 12 and again in the second half of the transit on May 15th. We c…
The bright $(V=3.86)$ star $β$ Pictoris is a nearby young star with a debris disk and gas giant exoplanet, $β$ Pictoris b, in a multi-decade orbit around it. Both the planet's orbit and disk are almost edge-on to our line of sight. We carry out a search for any transiting planets in the $β$ Pictoris system with orbits of less than 30 days that are coplanar with the planet $β$ Pictoris b. We search for a planetary transit using data from the BRITE-Constellation nanosatellite BRITE-Heweliusz, analyzing the photometry using the Box-Fitting Least Squares Algorithm (BLS). The sensitivity of the met…
Because the planets of a system form in a flattened disk, they are expected to share similar orbital inclinations at the end of their formation. The high-precision photometric monitoring of stars known to host a transiting planet could thus reveal the transits of one or more other planets. We investigate here the potential of this approach for the M dwarf GJ 1214 that hosts a transiting super-Earth. For this system, we infer the transit probabilities as a function of orbital periods. Using Monte-Carlo simulations we address both the cases for fully coplanar and for non-coplanar orbits, with th…
Currently, we have only limited means to probe the presence of planets at large orbital separations. Foreman-Mackey et al. searched for long-period transiting planets in the Kepler light curves using an automated pipeline. Here, we apply their pipeline, with minor modifications, to a larger sample and use updated stellar parameters from Gaia DR2. The latter boosts the stellar radii for most of the planet candidates found by FM16, invalidating a number of them as false positives. We identify 15 candidates, including two new ones. All have sizes from 0.3 to 1 $R_{\rm J}$, and all but two have pe…
The Multi-site All-sky CAmeRA MASCARA is an instrument concept consisting of several stations across the globe, with each station containing a battery of low-cost cameras to monitor the near-entire sky at each location. Once all stations have been installed, MASCARA will be able to provide a nearly 24-hr coverage of the complete dark sky, down to magnitude 8, at sub-minute cadence. Its purpose is to find the brightest transiting exoplanet systems, expected in the V=4-8 magnitude range - currently not probed by space- or ground-based surveys. The bright/nearby transiting planet systems, which M…
Kepler-730 is a planetary system hosting a statistically validated hot Jupiter in a 6.49-day orbit and an additional transiting candidate in a 2.85-day orbit. We use spectroscopic radial velocities from the APOGEE-2N instrument, Robo-AO contrast curves, and Gaia distance estimates to statistically validate the planetary nature of the additional Earth-sized candidate. We perform astrophysical false positive probability calculations for the candidate using the available Kepler data and bolster the statistical validation by using radial velocity data to exclude a family of possible binary star so…
