bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transits in Poorly Sampled Data – Gaia and Beyond
Authors: Tingley Brandon 
Published: February 2009

AbstractGaia, an ESA cornerstone mission, will obtain of the order of 100 high-precision photometric observations over five years for tens of millions of stars with V < 17. The vast number of red dwarfs in this data set, with their correspondingly deep (high S/N) transits, makes it worthwhile to explore the possibility of detecting transits in such data. Searching for transits under these circumstances requires a very different approach from that used for a normal, highly-sampled transit survey if the search is to be performed in a reasonable amount of time. It should be possible to identify a portion of the transiting Hot Jupiter/M dwarf systems in the data set, if the photometry is as stable and precise as specified by design. This same approach could be applied to ground-based transit searches – a transit survey targeted at red dwarfs with Jupiter-sized companions.
How to use the Phoebe code to solve transiting exoplanet light curve
Authors: Poddaný Stanislav 
Published: February 2009

AbstractA brief demonstration of photometric light curves solutions for eight transiting exoplanets using the Phoebe 0.29c code is presented. We determined radii and inclinations for TrES-1b, TrES-2b, Wasp-1b, XO-1b, XO-2b, OGLE-TR-10b, OGLE-TR-111b and HD 189733b. All our results are in good agreement with the last results published.
Towards a fully automated eclipsing binary solver for Gaia
Authors: Tingley Brandon , Sadowski Gilles , Siopis Christos 
Published: February 2009

AbstractGaia, an ESA cornerstone mission, will obtain of the order of 100 high-precision photometric observations and lower precision radial velocity measurements over five years for around a billion stars – several hundred thousand of which will be eclipsing binaries. In order to extract the characteristics of these systems, a fully automated code must be available. During the process of this development, two tools that may be of use to the transit community have emerged: a very fast, simple, detached eclipsing binary simulator/solver based on a new approach and an interacting eclipsing binary simulator with most of the features of the Wilson-Devinney and Nightfall codes, but fully documented and written in easy-to-follow and highly portable Java. Currently undergoing development and testing, this code includes an intuitive graphical interface and an optimizer for the estimation of the physical parameters of the system.
From stars to planets
Authors: Gazzano Jean-Christophe , Deleuil Magali , De Laverny Patrick , Blanco Alejandra Recio , Bouchy François , Gandolfi Davide , Loeillet Benoît 
Published: February 2009

AbstractA large program of multi-fibre (FLAMES) spectroscopic observations of the stellar population in two CoRoT/Exoplanet field with the GIRAFFE/VLT, took place in spring 2008. It aims at characterizing the brightest dwarf population and providing the ground for statistical analysis of the planetary population found by CoRoT.To perform such an ambitious analysis, we use an automated software based on the MATISSE algorithm, originally designed for the GAIA/RVS spectral analysis. This software derives the atmospheric stellar parameters: effective temperature, surface gravity and the overall metallicity.Further improvements are foreseen in order to measure also individual abundances. By comparing the main physical and chemical properties of the host stars to those of the stellar population they belong to, this will bring new insights into the formation and evolution of exoplanetary systems and the star-planet connection.
DEMONEX: The DEdicated MONitor of EXotransits
Authors: Eastman J. D. , Gaudi B. S. , DePoy D. L. 
Published: February 2009

AbstractDEMONEX is a low-cost, 0.5 meter, robotic telescope assembled mostly from commercially available parts dedicated to obtaining precise photometry of bright stars with transiting planets. This photometry will provide a homogeneous data set for all transits visible from its location at Winer Observatory in Sonoita, Arizona. We will also search for additional planets via transit timing variations, measure or place limits on the albedos from secondary eclipses, systematically search known radial velocity planets for those that transit, and follow up promising KELT candidates. Despite its modest size, the signal-to-noise ratio per transit is comparable to that obtained with larger, 1m-class telescopes because of its short readout time and high z-band quantum efficiency. However, its main strength is that it will be used every night for transit follow-up and gather an unprecedented data set on transiting planets. With the 24 known transiting planets and 112 radial velocity planets visible from Winer Observatory, over 90% of all nights have at least one full event to observe.
GJ 436c? The contribution of transit timings
Authors: Demory B.-O. , Gillon M. , Waelkens C. , Queloz D. , Udry S. 
Published: February 2009

AbstractFrom recent high-accuracy transit timings measurements, we discard the 5 M⊕ planet recently proposed by Ribas et al. (2008). Thanks to a combined radial-velocity and transit timings overview we also define a mass/period domain in which a secondary planet may be found in the system. We also show that timings obtained until now, although not sufficient to remove degeneracies on mass and period, can still restrict the parameter space of the potential secondary planet.
Transit timing variability in TrES-1
Authors: Rabus M. , Alonso R. , Deeg H. J. , Belmonte J. A. , Almenara J. M. , Gilliland R. L. , Brown T. M. 
Published: February 2009

AbstractWe observed several transits of the exoplanet TrES-1 distributed over four years from 2004 to 2007. On the basis of these observations and additional published data, we present a mid-transit time analysis. The aim is to find indications of the presence of a third body by analysing the difference between the calculated and observed transit times.
Searching for transit timing variations in transiting exoplanet systems
Authors: Hrudková Marie , Skillen Ian , Benn Chris , Pollacco Don , Gibson Neale , Joshi Yogesh , Harmanec Petr , Tulloch Simon 
Published: February 2009

AbstractSearching for transit timing variations in the known transiting exoplanet systems can reveal the presence of other bodies in the system. Here we report such searches for two transiting exoplanet systems, TrES-1 and WASP-2. Their new transits were observed with the 4.2m William Herschel Telescope located on La Palma, Spain. In a continuing programme, three consecutive transits were observed for TrES-1, and one for WASP-2 during September 2007. We used the Markov Chain Monte Carlo simulations to derive transit times and their uncertainties. The resulting transit times are consistent with the most recent ephemerides and no conclusive proof of additional bodies in either system was found.
Period variations in extrasolar transiting planet OGLE-TR-111b
Authors: Díaz Rodrigo F. , Rojo Patricio , Melita Mario , Hoyer Sergio , Minniti Dante , Mauas Pablo J. D. , Ruíz María Teresa 
Published: February 2009

AbstractTwo consecutive transits of planetary companion OGLE-TR-111b were observed in the I band. Combining these observations with data from the literature, we find that the timing of the transits cannot be explained by a constant period, and that the observed variations cannot be originated by the presence of a satellite. However, a perturbing planet with the mass of the Earth in an exterior orbit could explain the observations if the orbit of OGLE-TR-111b is eccentric. We also show that the eccentricity needed to explain the observations is not ruled out by the radial velocity data found in the literature.
Stellar activity of planetary host star HD 189733
Authors: Boisse I. , Moutou C. , Vidal-Madjar A. , Bouchy F. , Pont F. , Hébrard G. , Bonfils X. , Delfosse X. , Desort M. , Forveille T. , Lagrange A.-M. , Loeillet B. , Lovis C. , Mayor M. , Pepe F. , Perrier C. , Queloz D. , Santos N. , Ségransan D. , Udry S. 
Published: February 2009

AbstractExoplanet search programs need to study how to disentangle radial-velocity (RV) variations due to Doppler motion and the noise induced by stellar activity. We monitored the active K2V HD 189733 with the high-resolution SOPHIE spectrograph (OHP, France). We refined the orbital parameters of HD 189733b and put limitations on the eccentricity and on a long-term velocity gradient. We subtracted the orbital motion of the planet and compared the variability of activity spectroscopic indices (HeI, Hα, Ca II H&K lines) to the evolution of the RV residuals and the shape of spectral lines. All are in agreement with an active stellar surface in rotation. We used such correlations to correct for the RV jitter due to stellar activity. This results in achieving a high precision on the orbital parameters, with a semi-amplitude: K=200.56±0.88m⋅s−1 and a derived planet mass of MP=1.13±0.03 MJup.
A Precise Estimate of the Radius of HD 149026b
Authors: Nutzman Philip , Charbonneau David , Winn Joshua N. , Knutson Heather A. , Fortney Jonathan J. , Holman Matthew J. , Agol Eric 
Published: February 2009

AbstractWe present Spitzer 8 μm transit observations of the extrasolar planet system HD 149026b. At this wavelength, transit light curves are weakly affected by stellar limb-darkening, allowing for a simpler and more accurate determination of planetary parameters. We measure a planet-star radius ratio of Rp/R∗=0.05158±0.00077, and in combination with ground-based data and independent constraints on the stellar mass and radius, we derive an orbital inclination of i = 85°.4+0°.9−0°.8 and a planet radius of 0.755 ± 0.040 RJ. These measurements further support models in which the planet is greatly enriched in heavy elements.
The NStED Stellar and Exoplanet Hosting Star Service
Authors: Ramirez S. , Ali B. , Baker R. , Berriman G. B. , von Braun K. , Chiu N-M. , Ciardi D. R. , Good J. , Kane S. R. , Laity A. C. , McElroy D. L. , Monkewitz S. , Payne A. N. , Schmitz M. , Stauffer J. R. , Wyatt P. L. , Zhang A. 
Published: February 2009

AbstractThe NASA Star and Exoplanet Database (NStED) is a general purpose stellar archive with the aim of providing support for NASA's planet finding and characterization goals, stellar astrophysics, and the planning of NASA and other space missions. There are two principal components of NStED: a database of (currently) 140,000 nearby stars and exoplanet-hosting stars, and an archive dedicated to high precision photometric surveys for transiting exoplanets. We present a summary of the NStED stellar database, functionality, tools, and user interface. NStED currently serves the following kinds of data for 140,000 stars (where available): coordinates, multiplicity, proper motion, parallax, spectral type, multiband photometry, radial velocity, metallicity, chromospheric and coronal activity index, and rotation velocity/period. Furthermore, the following derived quantities are given wherever possible: distance, effective temperature, mass, radius, luminosity, space motions, and physical/angular dimensions of habitable zone. Queries to NStED can be made using constraints on any combination of the above parameters. In addition, NStED provides tools to derive specific inferred quantities for the stars in the database, cross-referenced with available extra-solar planetary data for those host stars. NStED can be accessed at http://nsted.ipac.caltech.edu.
The NStED Exoplanet Transit Survey Service
Authors: von Braun K. , Abajian M. , Ali B. , Baker R. , Berriman G. B. , Chiu N-M. , Ciardi D. R. , Good J. , Kane S. R. , Laity A. C. , McElroy D. L. , Monkewitz S. , Payne A. N. , Ramirez S. , Schmitz M. , Stauffer J. R. , Wyatt P. L. , Zhang A. 
Published: February 2009

AbstractThe NASA Star and Exoplanet Database (NStED) is a general purpose stellar archive with the aim of providing support for NASA's planet finding and characterization goals, stellar astrophysics, and the planning of NASA and other space missions. There are two principal components of NStED: a database of (currently) 140,000 nearby stars and exoplanet-hosting stars, and an archive dedicated to high-precision photometric surveys for transiting exoplanets. We present a summary of the latter component: the NStED Exoplanet Transit Survey Service (NStED-ETSS), along with its content, functionality, tools, and user interface. NStED-ETSS currently serves data from the TrES Survey of the Kepler Field as well as dedicated photometric surveys of four stellar clusters. NStED-ETSS aims to serve both the surveys and the broader astronomical community by archiving these data and making them available in a homogeneous format. Examples of usability of ETSS include investigation of any time-variable phenomena in data sets not studied by the original survey team, application of different techniques or algorithms for planet transit detections, combination of data from different surveys for given objects, statistical studies, etc. NStED-ETSS can be accessed at http://nsted.ipac.caltech.edu.
Identifying Non-transiting Terrestrial Planets with Transit Timing Data
Authors: Veras Dimitri , Ford Eric B. 
Published: February 2009

AbstractBoth ground and space-based transit observatories are poised to significantly increase the number of known transiting planets and the number of precisely measured transit times. A planet's transit times represent a clock that can be used to infer the presence of additional planets. Although modeling the transit time variations (TTVs) of a known system is simple, interpreting those variations in terms of the mass and orbital elements of a perturbing planet is much more challenging. Because mutual planetary perturbations are often the dominant source of TTVs, the observable signal can be extremely complex. In these proceedings, we present early results based on a simplistic analysis of the root-mean-square TTV deviation amplitude. We are preparing a more thorough analysis based on a computationally efficient surrogate Bayesian model, which may be combined with analytic approximations and n-body integrations in order to establish the sensitivity of TTV observations to terrestrial-like planets as a function of the system architecture. Besides aiding the interpretation of future transit timing observations, we hope our results can help maximize the productivity of transit timing follow-up campaigns by guiding survey design decisions such as the choice of targets, required precision, and desired number/time span of TTV observations.
Observability of the General Relativistic Precession of Periastra in Exoplanets
Authors: Jordán Andrés , Bakos Gáspár Á. 
Published: February 2009

AbstractThe general relativistic precession rate of periastra in close-in exoplanets can be orders of magnitude larger than the magnitude of the same effect for Mercury. The realization that some of the close-in exoplanets have significant eccentricities raises the possibility that this precession might be detectable. We explore here the observability of the periastra precession using radial velocity and transit light curve observations. Our analysis is independent of the source of precession, which can also have significant contributions due to additional planets and tidal deformations. We find that precession of the periastra of the magnitude expected from general relativity can be detectable in timescales of ≲10 years with current observational capabilities by measuring the change in the primary transit duration or in the time difference between primary and secondary transits. Radial velocity curves alone would be able to detect this precession for super-massive, close-in exoplanets orbiting inactive stars if they have ~100 datapoints at each of two epochs separated by ~20 years. The contribution to the precession by tidal deformations may dominate the total precession in cases where the relativistic precession is detectable. Studies of transit durations withKeplermight need to take into account effects arising from the general relativistic and tidal induced precession of periastra for systems containing close-in, eccentric exoplanets. Such studies may be able to detect additional planets with masses comparable to that of Earth by detecting secular variations in the transit duration induced by the changing longitude of periastron.
The impact of stellar jitter on the confirmation of transiting exoplanet candidates around Solar-like stars
Authors: Tingley Brandon , Grundahl Frank , Kjeldsen Hans 
Published: February 2009

AbstractThe radial velocity technique is commonly used to classify transiting exoplanet candidates. However, stars are intrinsically noisy in radial velocity. No good description of this noise has yet been proffered, although activity in general has been suggested as the source, making it impossible to evaluate its effect on signal detection. In this poster, we propose an activity-based model that incorporates both light and dark stellar spots, capable of producing both photometric and radial velocity time series. We demonstrate its consistency with both SOHO/VIRGO photometry and SOHO/GOLF radial velocities. We then use this model to establish lower and upper limits on the effects of intrinsic stellar noise on the metal lines used to follow up transit candidates, making use of Monte Carlo simulations. Based on these results, we can suggest an optimal observational sampling rate.
Ground-based detections of sodium in HD 209458b's atmosphere in two data sets
Authors: Albrecht S. , Snellen I. , de Mooij E. , Le Poole R. 
Published: February 2009

AbstractWe present two separate ground-based detections of sodium in the transmission spectrum of HD 209458b. First we reanalyzed an archival data set from the HDS spectrograph on Subaru, which shows sodium at a >5σ level. Secondly, our preliminary results of a UVES/VLT data set indicate sodium absorption at a similar level, although the data cover the eclipse only partially. Both results are fully consistent with the HST results of Charbonneau et al. (2002). The Na D absorption feature seems to be resolved in the narrowest passband.
Atmospheric composition and structure of HD209458b
Authors: Désert J.-M. , Vidal-Madjar A. , des Etangs A. Lecavelier , Sing D. , Ehrenreich D. , Hébrard G. , Ferlet R. 
Published: February 2009

AbstractTransiting planets like HD209458b offer a unique opportunity to scrutinize their atmospheric composition and structure. Transit spectroscopy probes the transition region between the day and night sides, called the limb. We present a re-analysis of existing HST/STIS transmission spectra of HD209458b's atmosphere. From these observations we identify H2 Rayleigh scattering, derive the absolute Sodium abundance and quantify its depletion in the upper atmosphere, extract a stratospheric T-P profile and find a temperature inversion and explain broad band absorptions with the presence of TiO and VO molecules.
Dynamical Simulations of HD 69830
Authors: Payne Matthew J. , Ford Eric B. , Wyatt Mark C. , Booth Mark 
Published: February 2009

AbstractPrevious studies have developed models for the growth and migration of three planets orbiting HD 69830. We perform n-body simulations using MERCURY (Chambers 1999) to explore the implications of these models for: 1) the excitation of planetary orbits via planet-planet interactions, 2) the accretion and clearing of a putative planetesimal disk, 3) the distribution of planetesimal orbits following migration, and 4) the implications for the origin of the observed infrared emission from the HD 69830 system. We report preliminary results that suggest new constraints on the formation of HD 69830.
Why have no transiting planets been found in star clusters?
Authors: Janes Kenneth , Kim Ji-Hyun 
Published: February 2009

AbstractSince the suggestion by Janes 1996 that star clusters might be attractive targets to search for transiting planets, there have been more than 20 searches in both open and globular clusters. To date, no confirmed hot Jupiter transiting planets have been found in clusters. We review the statistics for finding short-period planets and we summarize the open cluster work to date, including our own (so far negative) search in NGC 7789. While individually, the negative results are not surprising, the consistent failure to find planets in clusters may suggest differences in the formation or evolution of planetary systems in clusters.
Phase-differential NIR integral field spectroscopy of transiting Hot Jupiters
Authors: Angerhausen Daniel , Krabbe Alfred , Iserlohe Christof 
Published: February 2009

AbstractTransiting exoplanets provide a unique opportunity for follow up exploration through phase-differential observation of their emission and transmission spectra. From such spectra immediate clues about the atmospheric composition and the planets chemistry can be drawn. Such information is of imminent importance for the theory of the formation of planets in general as well as for their particular evolution. Ground-based spectroscopy of exoplanet transits is a needful extension of results already obtained through space-based observations. We present results of an exploratory study to use near-infrared integral field spectroscopy to observe extrasolar planets. We demonstrate how adaptive optics-assisted integral field spectroscopy compares with other spectroscopic techniques currently applied. An advanced reduction method using elements of a spectral-differential decorrelation method is also discussed. We have tested our concept with a K-Band time series observations of HD209458b and HD189733b obtained with SINFONI at the VLT and OSIRIS at Keck during secondary transits at a spectral resolution of R=3000.
The Impact of Transiting Planet Science on the Next Generation of Direct-Imaging Planet Searches
Authors: Carson Joseph C. 
Published: February 2009

AbstractWithin the next five years, a number of direct-imaging planet search instruments, like the VLT SPHERE instrument, will be coming online. To successfully carry out their programs, these instruments will rely heavily on a-priori information on planet composition, atmosphere, and evolution. Transiting planet surveys, while covering a different semi-major axis regime, have the potential to provide critical foundations for these next-generation surveys. For example, improved information on planetary evolutionary tracks may significantly impact the insights that can be drawn from direct-imaging statistical data. Other high-impact results from transiting planet science include information on mass-to-radius relationships as well as atmospheric absorption bands. The marriage of transiting planet and direct-imaging results may eventually give us the first complete picture of planet migration, multiplicity, and general evolution.
Getting More For Your Money: Identifying and Confirming Long-Period Planets with Kepler
Authors: Yee Jennifer C. , Gaudi B. Scott 
Published: February 2009

AbstractKepler will monitor enough stars that it is likely to detect single transits of planets with periods longer than the mission lifetime. We show that by combining the Kepler photometry of such transits with precise radial velocity (RV) observations taken over ~3 months, and assuming circular orbits, it is possible to estimate the periods of these transiting planets to better than 20% (for planets with radii greater than that of Neptune) and the masses to within a factor of 2 (for planet masses mp ≥ MJup). We also explore the effects of eccentricity on these quantities.