bluuebunny/crossref_metadata_2025_split huggingface dataset:
HAT-South: A Global Network of Southern Hemisphere Automated Telescopes to Detect Transiting Exoplanets
Authors: Bakos G. , Afonso C. , Henning T. , Jordán A. , Holman M. , Noyes R. W. , Sackett P. D. , Sasselov D. , Kovács Gábor , Csubry Z. , Pál A. 
Published: February 2009

AbstractHAT-South is a network of six identical, fully automated wide field telescopes, to be located at three sites (Chile: Las Campanas, Australia: Siding Springs, and Namibia: HESS site) in the Southern hemisphere. The primary purpose of the network is to detect and characterize a large number of extra-solar planets transiting nearby bright stars, and to explore their diversity. Operation of HAT-South is a collaboration among the Harvard-Smithsonian Center for Astrophysics (CfA), Max Planck Institute for Astronomy (MPIA) and the Australian National University (ANU). The network is expected to be ready for initial science operations in 2009. The three sites will permit near round-the-clock monitoring of selected fields, and the continuous data-stream will greatly enhance recovery of transits. HAT-South will be sensitive to planetary transits down to R≈14 across a 128 square-degrees combined field of view, thereby targeting a large number of dwarfs with feasible confirmation-mode follow-up. We anticipate a yearly detection rate of approximately 25 planets transiting bright stars.
Transit Detection of Radial Velocity Planets
Authors: Kane Stephen R. , von Braun Kaspar 
Published: February 2009

AbstractThe orbital parameters of extra-solar planets have a significant impact on the probability that the planet will transit the host star. This was recently demonstrated by the transit detection of HD 17156b whose favourable eccentricity and argument of periastron dramatically increased its transit likelihood. We present a study which provides a quantitative analysis of how these two orbital parameters affect the geometric transit probability as a function of period. Further, we apply these results to known radial velocity planets and show that there are unexpectedly high transit probabilities for planets at relatively long periods. For a photometric monitoring campaign which aims to determine if the planet indeed transits, we calculate the significance of a null result and the subsequent constraints that may be applied to orbital parameters.
Transiting exo-planets search for MOA-I data
Authors: Fukui A. , Abe F. , Bond I. A. , Furusawa K. , Hearnshow J. B. , Itow Y. , Kamiya K. , Kilmartin P. M. , Masuda K. , Matsubara Y. , Miyake N. , Muraki Y. , Nagaya M. , Noda S. , Ohnishi K. , Saito T. , Sako T. , Sato S. , Sullivan D. J. , Sumi T. , Tristram P. J. , Yanagisawa T. , Yock P. C. M. 
Published: February 2009

AbstractThe Microlensing Observations in Astrophysics (MOA) is a microlensing survey conducted at Mt. John Observatory in New Zealand. We searched transiting planet candidates from the MOA-I Galactic bulge data, which have been obtained with a 61cm B&C telescope from 2000 to 2005 for a microlensing search. Although this survey data were dedicated to microlensing, they are also quite useful for searching transiting objects because of the large number of stars monitored (~7 million) and the long span of the survey (~6 years). From our analysis, we found 58 transiting planet candidates. We are planning to follow up these candidates with high-precision spectroscopic and photometric observations for further selection, toward the detection of planets by radial velocity observations.
De-Trending Time Series Data for Variability Surveys
Authors: Kim Dae-Won , Protopapas Pavlos , Dave Rahul 
Published: February 2009

AbstractWe present an algorithm for the removal of trends in time series data. The trends could be caused by various systematic and random noise sources such as cloud passages, change of airmass or CCD noise. In order to determine the trends, we select template stars based on a hierarchical clustering algorithm. The hierarchy tree is constructed using the similarity matrix of light curves of stars whose elements are the Pearson correlation values. A new bottom-up merging algorithm is developed to extract clusters of template stars that are highly correlated among themselves, and may thus be used to identify the trends. We then use the multiple linear regression method to de-trend all individual light curves based on these determined trends. Experimental results with simulated light curves which contain artificial trends and events are presented. We also applied our algorithm to TAOS (Taiwan-American Occultation Survey) wide field data observed with a 0.5m f/1.9 telescope equipped with 2k by 2k CCD. With our approach, we successfully removed trends and increased signal to noise in TAOS light curves.
Application of the TRUFAS detection algorithm to the first two runs of CoRoT
Authors: Régulo Clara , Almenara Jose M. , Deeg Hans J. 
Published: February 2009

AbstractTRUFAS is a wavelet-based algorithm developed for the rapid detection of planetary transits in the frame of the COROT space mission. We present the application of this algorithm to the first two observing fields of CoRoT data. In these, CoRoT has observed a total of about 20000 stars. The first CoRoT observing run, IRa01, covers 2 months, February and March 2007, followed by the 5-months long run LRc01. TRUFAS is a very fast algorithm delivering reliable detections. Here we show the results when TRUFAS was applied to these first two sets of data. In the first run, IRa01, TRUFAS found 10 planet candidates and 143 eclipsing binaries and in the LRc01 10 planet candidates and 124 binaries, with a processing that lasted only one night.
Identifying Transiting Circumbinary Planets
Authors: Ofir Aviv 
Published: February 2009

AbstractTransiting planets manifest themselves by a periodic dimming of their host star by a fixed amount. On the other hand, light curves of transiting circumbinary (CB) planets are expected to be neither periodic nor to have a single depth while in transit, making the Box-Least-Squares (BLS) transit detection method almost ineffective. Therefore, a modified version for the identification of CB planets was developed - CB-BLS. We show that using CB-BLS it is possible to find CB planets in the residuals of light curves of eclipsing binaries (EBs) that have noise levels of 1% or more. Using CB-BLS will allow us to use the massive ground- and space-based photometric surveys to look for these objects. Detecting transiting CB planets is expected to have a wide range of implications. For instance, the frequency of CB planets depends on the planetary formation mechanism - and planets in close pairs of stars provide a most restrictive constraint on planet formation models. Furthermore, understanding very high precision light curves is limited by stellar parameters - and since for EBs the stellar parameters are much better determined, the resultant planetary structure models will have significantly smaller error bars, maybe even small enough to challenge theory.
An algorithm for the detection of transits of planets around eclipsing binaries in CoRoT
Authors: Almenara Jose Manuel , Deeg Hans J. , Lázaro Carlos , Arévalo María Jesús 
Published: February 2009

AbstractWe present a matched filter algorithm to detect transits of planets that orbit both components of close eclipsing binaries in CoRoT targets. The formation of binary systems surrounded by disks is one of the most common outcomes of stellar formation; their detection would therefore constitute an important discovery. In an eclipsing binary system, the binary-planet alignment gives raised transit probabilities and the special transit shapes from circumbinary planets provide a unique identifier for their planetary nature; the problems of false alarms are largely avoided. CoRoT data have unprecedented time coverage and photometric precision that make them especially suitable for the search of transits of planets across eclipsing binaries. No reliable detections of circumbinary planets have been reported yet, and their discovery would constitute a new class of planets.
UTM, a universal simulator for lightcurves of transiting systems
Authors: Deeg Hans 
Published: February 2009

AbstractThe Universal Transit Modeller (UTM) is a light-curve simulator for all kinds of transiting or eclipsing configurations between arbitrary numbers of several types of objects, which may be stars, planets, planetary moons, and planetary rings. Applications of UTM to date have been mainly in the generation of light-curves for the testing of detection algorithms. For the preparation of such test for the Corot Mission, a special version has been used to generate multicolour light-curves in Corot's passbands. A separate fitting program, UFIT (Universal Fitter) is part of the UTM distribution and may be used to derive best fits to light-curves for any set of continuously variable parameters. UTM/UFIT is written in IDL code and its source is released in the public domain under the GNU General Public License.
Analytic approximations for transit light curve observables and uncertainties
Authors: Carter Joshua A. , Yee Jennifer C. , Eastman Jason , Gaudi B. Scott , Winn Joshua N. 
Published: February 2009

AbstractThe light curve of an exoplanetary transit can be used to estimate the planetary radius and other parameters of interest. Because accurate parameter estimation is a non-analytic and computationally intensive problem, it is often useful to have analytic approximations for the parameters as well as their uncertainties and covariances. Here we give such formulas, for the case of an exoplanet transiting a star with a uniform brightness distribution. When limb darkening is significant, our parameter sets are still useful, although our analytic formulas underpredict the covariances and uncertainties.
Analysis of the light and radial velocity curves of transiting extra-solar planets
Authors: Giménez Alvaro 
Published: February 2009

AbstractSeveral approaches have been followed for the analysis of the light curves of transiting extra-solar planets. From simple approximate algorithms and synthetic models to semi-analytical complete solutions. The different alternatives are discussed with their strengths and weaknesses. Analytical expressions can also provide a deeper insight into the main system parameters from the measurement of a few strategic points describing the shape of the light curve.
Co-ordinated Follow-Up of Transiting Planet Candidates with Robotic Telescope Facilities
Authors: Street R. A. , Lister T. A. 
Published: February 2009

AbstractThere are now several large photometric surveys scanning millions of stellar light-curves for signs of planetary transits. All produce large candidate lists with a high false alarm rate, so that further observations are required to confirm new detections. One such survey, SuperWASP, produced ~150 candidates during the 2007–2008 season. Here we describe our campaign to follow-up 86 of these candidates using the robotic facilities of Las Cumbres Observatory Global Telescope Network and the Tenagra-II robotic telescope in Arizona. The aim of these observations was to eliminate false positives as far as possible ahead of spectroscopic follow-up and to provide additional photometry to help characterise the surviving targets.
Burrell-Optical-Kepler Survey (BOKS): A Variability Search in the Kepler Field
Authors: Proctor Amanda L. , Howell Steve B. , Sherry William H. , von Braun Kaspar , Everett Mark E. , Feldmeir John J. , Ciardi David R. 
Published: February 2009

AbstractWe present the results of eighteen non-continuous nights of time series photometric observations of a 1.25 deg2 field in Cygnus centered on the NASA Kepler Mission field of view. Using the Case Western Burrell Schmidt telescope we gathered a dataset containing light curves of roughly 30,000 stars with 14 < r < 19. We have statistically examined each light curve to test for variability, periodicity, and unusual light curve trends, including exoplanet transits. We present a summary of our photometric project including a characterization of the level and content of stellar variability in this field. We will also discuss our potential exoplanet candidates.
HD 17156 : a progress report
Authors: Barbieri Mauro , Alonso Roi , Cecconi M. , Claudi R. U. , Desidera S. , Endl M. , Fiorenzano A. F. Martinez , Gratton R. 
Published: February 2009

AbstractWe present an analysis of the HD planetary system based on a photometric transit dataset and radial velocities obtained on 3 December 2007. We also present limits on the presence of close stellar companions based on high resolution images.
Determination of stellar, orbital and planetary parameters using complete Monte-Carlo analysis – the case of HAT-P-7b
Authors: Pál András , Bakos Gáspár Á. , Noyes Robert W. , Torres Guillermo 
Published: February 2009

AbstractThe recently discovered transiting very hot Jupiter, HAT-P-7b, a planet detected by the telescopes of HATNet, turned out to be among the ones subjected to the highest irradiation from the parent star. In order to best characterize this particular planet, we carried out an analysis based on a complete and simultaneous Monte-Carlo solution using all available data. We included the discovery light curves, partial follow-up light curves, the radial velocity data, and we used the stellar evolution models to infer the stellar properties.This self-consistent way of modeling provides the most precise estimate of the a posteriori distributions of all of the system parameters of interest, and avoids making assumptions on the values and uncertainties of any of the internally derived variables describing the system. This analysis demonstrates that even partial light curve information can be valuable. This may become very important for future discoveries of planets with longer periods – and therefore longer transit durations – where the chance of observing a full event is small.
Observations of the transiting planet TrES-2 with the AIU Jena telescope in Großschwabhausen
Authors: Raetz S. , Mugrauer M. , Schmidt T. O. B. , Roell T. , Eisenbeiss T. , Hohle M. , Seifahrt A. , Koeltzsch A. , Vaňko M. , Broeg Ch. , Koppenhoefer J. , Neuhäuser R. 
Published: February 2009

AbstractWe have started high precision photometric monitoring observations at the AIU Jena observatory in Großschwabhausen near Jena in fall 2006. We used a 25.4cm Cassegrain telescope equipped with a CCD-camera mounted piggyback on a 90cm telescope. To test the attainable photometric precision, we observed stars with known transiting planets. We could recover all planetary transits observed by us.We observed the parent star of the transiting planet TrES-2 over a longer period in Großschwabhausen. Between March and November 2007 seven different transits and almost a complete orbital period were analyzed. Overall, in 31 nights of observation 3423 exposures (in total 57.05h of observation) of the TrES-2 parent star were taken. Here, we present our methods and the resulting light curves. Using our observations we could improve the orbital parameters of the system.
Transit observation at the observatory in Großschwabhausen: XO-1b and TrES-1
Authors: Vaňko M. , Raetz S. , Mugrauer M. , Schmidt T. O. B. , Roell T. , Eisenbeiss T. , Hohle M. , Seifahrt A. , Koeltzsch A. , Broeg C. , Koppenhoefer J. , Neuhäuser R. 
Published: February 2009

AbstractWe report on observations of transit events of the transiting planets XO-1b and TrES-1 with the AIU Jena telescope in Großschwabhausen. Based on our (IR) photometry (in March 2007) and available transit timings (SuperWASP, XO and TLC-project-data) we improved the orbital period of XO-1b (P = 3.941497 ± 0.000006) and TrES-1 (P = 3.0300737 ± 0.000006), respectively. The new ephemeris for the both systems are presented.
Optical Follow up Photometry of the Transiting Extrasolar Planet XO-2
Authors: Fernandez Jose M. , Holman Matthew J. , Winn Joshua N. 
Published: February 2009

AbstractWe present three full z-band transit light curves for the extrasolar planet XO-2 obtained with KeplerCam and the FLWO 1.2m telescope. The system parameters were determined fitting the data to transit models using a Markov Chain Monte Carlo simulation (MCMC). The main results presented in this poster are revised values for the parameters Rp/Rs, a/Rs and b.
Observing exoplanets from Brazil: the first try
Authors: Saito Roberto , Silva Paulo Henrique , Kanaan Antonio , Schoenell William , Fraga Luciano , Bruch Albert 
Published: February 2009

AbstractThis project consists in mapping a 4-square-degree region searching for exoplanets using the transit method. This “mini-survey” will be the first use of the 16″ robotic telescope developed by Universidade Federal de Santa Catarina (UFSC-Brazil) and Laboratório Nacional de Astrofísica (LNA/MCT-Brazil). The chosen region is over the Columba constellation and our first observations have shown that we have enough signal-to-noise ratio to search for transits on about 20,000 stars with ~13 < I < 16 mag, a magnitude range between the OGLE and HAT projects. In this star sample we expect to find about a dozen planets with transits duration of 1-3 hours and magnitude depth from 0.001 to 0.010 mag. As for other projects, all information will became public as a VO service.
Radio cyclotron emission from extra-solar planets
Authors: Smith Alexis , Cameron Andrew , Greaves Jane , Jardine Moira , Langston Glen , Backer Donald 
Published: February 2009

AbstractWe present results from an attempt to detect radio emission from the interaction between a transiting extra-solar planet and its host star. We determine a new upper limit of 47 mJy on the radio flux density from HD 189733b, in the frequency range 327–347 MHz.
MOST Spacebased Photometry of HD 189733: Precise Timing Measurements for Transits Across an Active Star
Authors: Miller-Ricci E. , Rowe J. F. , Sasselov D. , Matthews J. M. , Kuschnig R. , Croll B. , Guenther D. B. , Moffat A. F. J. , Rucinski S. , Walker G. A. H , Weiss W. W. 
Published: February 2009

AbstractWe have measured transit times for HD 189733 passing in front of its bright (V = 7.67) chromospherically active and spotted parent star. Nearly continuous broadband photometry of this system was obtained with the MOST (Microvariability & Oscillations of STars) space telesope during 21 days in August 2006, monitoring 10 consecutive transits. We have used these data to search for deviations from a constant orbital period which can indicate the presence of additional planets in the system that are as yet undetected by Doppler searches. We find no variations above the level of ±45 s, ruling out planets in the Earth-to-Neptune mass range in a number of resonant orbits. We find that a number of complications can arise in measuring transit times for a planet transiting an active star with large star spots. However, such transiting systems are also useful in that they can help to constrain and test spot models. This has implications for the large number of transiting systems expected to be discovered by the CoRoT and Kepler missions.
Preliminary Results on HAT-P-4, TrES-3, XO-2, and GJ 436 from the NASA EPOXI Mission
Authors: Ballard Sarah , Charbonneau David , A'Hearn Michael F. , Deming Drake , Holman Matthew J. , Christiansen Jessie L. , Weldrake David T. F. , Barry Richard K. , Kuchner Marc J. , Livengood Timothy A. , Pedelty Jeffrey , Schultz Alfred , Hewagama Tilak , Sunshine Jessica M. , Wellnitz Dennis D. , Hampton Don L. , Lisse Carey M. , Seager Sara , Veverka Joseph F. 
Published: February 2009

AbstractEPOXI (EPOCh + DIXI) is a NASA Discovery Program Mission of Opportunity using the Deep Impact flyby spacecraft. The EPOCh (Extrasolar Planet Observation and Characterization) Science Investigation will gather photometric time series of known transiting exoplanet systems from January through August 2008. Here we describe the steps in the photometric extraction of the time series and present preliminary results of the first four EPOCh targets.
Toward a homogeneous set of transiting planet parameters
Authors: Torres Guillermo , Winn Joshua N. , Holman Matthew J. 
Published: February 2009

AbstractWith 40 or more transiting exoplanets now known, the time is ripe to seek patterns and correlations among their observed properties, which may give important insights into planet formation, structure, and evolution. This task is made difficult by the widely different methodologies that have been applied to measure their properties in individual cases. Furthermore, in many systems our knowledge of the planet properties is limited by the knowledge of the properties of the parent stars. To address these difficulties we have undertaken the first comprehensive analysis of the data for 23 transiting planets using a uniform methodology. We revisit several of the recently proposed correlations, and find new ones involving the metallicity of the parent stars.
Eccentric Planets & Transit Time Variation
Authors: Kipping David M. , Ribas Ignasi , Font-Ribera Andreu 
Published: February 2009

AbstractFor an extrasolar planet on an eccentric orbit, the orbital velocity is constantly changing, even during a planetary transit. This changing orbital velocity will, in general, cause lightcurve assymetry. The asymmetry causes the mid-transit time to be slightly off-centre from the halfway point between transit ingress and egress. For GJ436b, we estimate that the mid-transit time is shifted by 20 seconds. In the case of a system experiencing secular changes, this difference will lead to a long period transit time variation (L-TTV) signal, under the typical definition of the mid-transit time. In this work, we describe the origins of the effect and evaluate it in the case of GJ436b experiencing hypothetical secular changes. We predict L-TTV could be used to map secular changes in such systems.
A Search for Exotrojans in Transiting Exoplanetary systems
Authors: Madhusudhan N. , Winn Joshua N. 
Published: February 2009

AbstractWe present a search for Trojan companions to 25 transiting exoplanets. We use the technique of Ford & Gaudi, in which a difference is sought between the observed transit time and the transit time that is calculated by fitting a two-body Keplerian orbit to the radial-velocity data. This technique is sensitive to the imbalance of mass at the L4/L5 points of the planet-star orbit. No companions were detected. The median 2σ upper limit is 60 M⊕, and the most constraining limit is 2.5 M⊕ for the case of GJ 436.
Astro-comb: revolutionizing precision spectroscopy in astrophysics
Authors: Cramer Claire E. , Li Chih-Hao , Benedick Andrew J. , Glenday Alexander G. , Kärtner Franz X. , Phillips David F. , Sasselov Dimitar , Szentgyorgyi Andrew , Walsworth Ronald L. 
Published: February 2009

AbstractSearches for extrasolar planets using the periodic Doppler shift of stellar spectral lines have recently achieved a precision better than 60cm/s. To find a 1-Earth mass planet in an Earth-like orbit, a precision of 5cm/s is necessary. The combination of a laser frequency comb with a Fabry-Perot filtering cavity has been suggested as a promising approach to achieve such Doppler shift resolution via improved spectrograph wavelength calibration. Here we report the fabrication of such a filtered laser comb with up to 40 GHz (~1 Angstrom) line spacing, generated from a 1 GHz repetition-rate source, without compromising long-term stability, reproducibility or spectral resolution. This wide-line-spacing comb (astro-comb) is well matched to the resolving power of high-resolution astrophysical spectrographs. The astrocomb should allow a precision as high as 1cm/s in astronomical readial velocity measurements.