scholarly journals TheKepler Missionand Eclipsing Binaries

2006 ◽  
Vol 2 (S240) ◽  
pp. 236-243 ◽  
Author(s):  
David Koch ◽  
William Borucki ◽  
Gibor Basri ◽  
Timothy Brown ◽  
Douglas Caldwell ◽  
...  
Keyword(s):  
Eclipsing Binaries ◽  
Light Curves ◽  
Field Of View ◽  
Habitable Zone ◽  
Target List ◽  
Kepler Mission ◽  
Photometric Observations ◽  
Single Field ◽  
Verification Process

AbstractTheKepler Missionis a space-based photometric mission with a differential photometric precision of 14 ppm (atV= 12 for a 6.5 hour transit). It is designed to continuously observe a single field of view (FOV) of greater then 100 square degrees in the Cygnus-Lyra region for four or more years. The primary goal of the mission is to monitor more than one-hundred thousand stars for transits of Earth-size and smaller planets in the habitable zone of solar-like stars. In the process, many eclipsing binaries (EB) will also be detected and light curves produced. To enhance and optimize the mission results, the stellar characteristics for all the stars in theKeplerFOV withV< 16 will have been determined prior to launch. As part of the verification process, stars with transit candidates will have radial-velocity follow-up observations performed to determine the component masses and thereby separate eclipses caused by stellar companions from transits caused by planets. The result will be a rich database on EBs. The community will have access to the archive for further analysis, such as, for EB modeling of the high-precision light curves. A guest observer program is also planned to allow for photometric observations of objects not on the target list but within the FOV.

scholarly journals Finding Earth-size planets in the habitable zone: theKepler Mission

2007 ◽  
Vol 3 (S249) ◽  
pp. 17-24 ◽  
Author(s):  
William Borucki ◽  
David Koch ◽  
Gibor Basri ◽  
Natalie Batalha ◽  
Timothy Brown ◽  
...  
Keyword(s):  
Field Of View ◽  
Mission Design ◽  
Habitable Zone ◽  
Analysis Pipeline ◽  
Dwarf Stars ◽  
Astrophysical Data ◽  
Kepler Mission ◽  
Single Field ◽  
Data Program

AbstractTheKepler Missionis a space-based mission whose primary goal is to detect Earth-size and smaller planets in the habitable zone of solar-like stars. The mission will monitor more than 100,000 stars for transits with a differential photometric precision of 20 ppm at V=12 for a 6.5 hour transit. It will also provide asteroseismic results on several thousand dwarf stars. It is specifically designed to continuously observe a single field of view of greater than 100 square degrees for 3.5 or more years.This overview describes the mission design, its goals and capabilities, the measured performance for those photometer components that have now been tested, the Kepler Input Catalog, an overview of the analysis pipeline, the plans for the Follow-up Observing Program to validate the detections and characterize the parent stars, and finally, the plans for the Guest Observer and Astrophysical Data Program.

scholarly journals KEPLER: Search for Earth-Size Planets in the Habitable Zone

2008 ◽  
Vol 4 (S253) ◽  
pp. 289-299 ◽  
Author(s):  
William Borucki ◽  
David Koch ◽  
Natalie Batalha ◽  
Douglas Caldwell ◽  
Jorgen Christensen-Dalsgaard ◽  
...  
Keyword(s):  
Field Of View ◽  
Habitable Zone ◽  
Dwarf Stars ◽  
Astrophysical Data ◽  
Short Overview ◽  
Kepler Mission ◽  
History Of ◽  
Single Field

AbstractThe Kepler Mission is a space-based mission whose primary goal is to determine the frequency of Earth-size and larger planets in the habitable zone of solar-like stars. The mission will monitor more than 100,000 stars for patterns of transits with a differential photometric precision of 20 ppm at V = 12 for a 6.5 hour transit. It will also provide asteroseismic results on several thousand dwarf stars. It is specifically designed to continuously observe a single field of view of greater than 100 square degrees for 3.5 or more years.This paper provides a short overview of the mission, a brief history of the mission development, expected results, new investigations by the recently chosen Participating Scientists, and the plans for the Guest Observer and Astrophysical Data Programs.

scholarly journals SuperWASP variable stars: classifying light curves using citizen science

2021 ◽  
Vol 502 (1) ◽  
pp. 1299-1311
Author(s):  
Heidi B Thiemann ◽  
Andrew J Norton ◽  
Hugh J Dickinson ◽  
Adam McMaster ◽  
Ulrich C Kolb
Keyword(s):  
Variable Stars ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Data Set ◽  
Resultant Data ◽  
Sky Survey ◽  
Short Period ◽  
Contact Binaries ◽  
Analysis Of Results

ABSTRACT We present the first analysis of results from the SuperWASP variable stars Zooniverse project, which is aiming to classify 1.6 million phase-folded light curves of candidate stellar variables observed by the SuperWASP all sky survey with periods detected in the SuperWASP periodicity catalogue. The resultant data set currently contains &gt;1 million classifications corresponding to &gt;500 000 object–period combinations, provided by citizen–scientist volunteers. Volunteer-classified light curves have ∼89 per cent accuracy for detached and semidetached eclipsing binaries, but only ∼9 per cent accuracy for rotationally modulated variables, based on known objects. We demonstrate that this Zooniverse project will be valuable for both population studies of individual variable types and the identification of stellar variables for follow-up. We present preliminary findings on various unique and extreme variables in this analysis, including long-period contact binaries and binaries near the short-period cut-off, and we identify 301 previously unknown binaries and pulsators. We are now in the process of developing a web portal to enable other researchers to access the outputs of the SuperWASP variable stars project.

scholarly journals Studying bright variable stars with the Multi-site All-Sky CAmeRA (MASCARA)

2018 ◽  
Vol 617 ◽  
pp. A32 ◽  
Author(s):  
O. Burggraaff ◽  
G. J. J. Talens ◽  
J. Spronck ◽  
A.-L. Lesage ◽  
R. Stuik ◽  
...  
Keyword(s):  
Variable Stars ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Previous Record ◽  
La Palma ◽  
Powerful Means ◽  
New Variables ◽  
Candidate Variable ◽  
Order Variability

Context. The Multi-site All-Sky CAmeRA (MASCARA) aims to find the brightest transiting planet systems by monitoring the full sky at magnitudes 4 < V < 8.4, taking data every 6.4 s. The northern station has been operational on La Palma since February 2015. These data can also be used for other scientific purposes, such as the study of variable stars. Aims. In this paper we aim to assess the value of MASCARA data for studying variable stars by determining to what extent known variable stars can be recovered and characterised, and how well new, unknown variables can be discovered. Methods. We used the first 14 months of MASCARA data, consisting of the light curves of 53 401 stars with up to one million flux points per object. All stars were cross-matched with the VSX catalogue to identify known variables. The MASCARA light curves were searched for periodic flux variability using generalised Lomb–Scargle periodograms. If significant variability of a known variable was detected, the found period and amplitude were compared with those listed in the VSX database. If no previous record of variability was found, the data were phase folded to attempt a classification. Results. Of the 1919 known variable stars in the MASCARA sample with periods 0.1 < P < 10 days, amplitudes >2%, and that have more than 80 h of data, 93.5% are recovered. In addition, the periods of 210 stars without a previous VSX record were determined, and 282 candidate variable stars were newly identified. We also investigated whether second order variability effects could be identified. The O’Connell effect is seen in seven eclipsing binaries, of which two have no previous record of this effect. Conclusions. MASCARA data are very well suited to study known variable stars. They also serve as a powerful means to find new variables among the brightest stars in the sky. Follow-up is required to ensure that the observed variability does not originate from faint background objects.

scholarly journals Survival of planets around shrinking stellar binaries

2015 ◽  
Vol 112 (30) ◽  
pp. 9264-9269 ◽  
Author(s):  
Diego J. Muñoz ◽  
Dong Lai
Keyword(s):  
Binary Stars ◽  
Orbital Evolution ◽  
Eclipsing Binaries ◽  
Target List ◽  
Tidal Dissipation ◽  
Compact Binaries ◽  
Kepler Mission ◽  
Orbital Decay ◽  
Erratic Behavior ◽  
Circumbinary Planets

The discovery of transiting circumbinary planets by the Kepler mission suggests that planets can form efficiently around binary stars. None of the stellar binaries currently known to host planets has a period shorter than 7 d, despite the large number of eclipsing binaries found in the Kepler target list with periods shorter than a few days. These compact binaries are believed to have evolved from wider orbits into their current configurations via the so-called Lidov–Kozai migration mechanism, in which gravitational perturbations from a distant tertiary companion induce large-amplitude eccentricity oscillations in the binary, followed by orbital decay and circularization due to tidal dissipation in the stars. Here we explore the orbital evolution of planets around binaries undergoing orbital decay by this mechanism. We show that planets may survive and become misaligned from their host binary, or may develop erratic behavior in eccentricity, resulting in their consumption by the stars or ejection from the system as the binary decays. Our results suggest that circumbinary planets around compact binaries could still exist, and we offer predictions as to what their orbital configurations should be like.

scholarly journals Expected performances of the Characterising Exoplanet Satellite (CHEOPS)

2020 ◽  
Vol 635 ◽  
pp. A24 ◽  
Author(s):  
S. Hoyer ◽  
P. Guterman ◽  
O. Demangeon ◽  
S. G. Sousa ◽  
M. Deleuil ◽  
...  
Keyword(s):  
Light Curves ◽  
Field Of View ◽  
Current Status ◽  
Point Spread ◽  
Single Target ◽  
Science Operations ◽  
Spread Function ◽  
And Performance ◽  
Irregular Point

The CHaracterizing ExOPlanet Satellite (CHEOPS) is set to be launched in December 2019 and will detect and characterize small size exoplanets via ultra high precision photometry during transits. CHEOPS is designed as a follow-up telescope and therefore it will monitor a single target at a time. The scientific users will retrieve science-ready light curves of the target that will be automatically generated by the CHEOPS data reduction pipeline of the Science Operations Centre. This paper describes how the pipeline processes the series of raw images and, in particular, how it handles the specificities of CHEOPS data, such as the rotating field of view, the extended irregular point spread function, and the data temporal gaps in the context of the strict photometric requirements of the mission. The current status and performance of the main processing stages of the pipeline, that is the calibration, correction, and photometry, are presented to allow the users to understand how the science-ready data have been derived. Finally, the general performance of the pipeline is illustrated via the processing of representative scientific cases generated by the mission simulator.

scholarly journals Ground-based photometry for 42 Kepler-field RR Lyrae stars

2013 ◽  
Vol 9 (S301) ◽  
pp. 427-428 ◽  
Author(s):  
Young-Beom Jeon ◽  
Chow-Choong Ngeow ◽  
James M. Nemec
Keyword(s):  
Light Curves ◽  
Astronomy Observatory ◽  
Color Information ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
Photometric Observations ◽  
Data Points ◽  
Optical Astronomy ◽  
Lyrae Stars

AbstractFollow-up (U)BVRI photometric observations have been carried out for 42 RR Lyrae stars in the Kepler field. The new magnitude and color information will complement the available extensive high-precision Kepler photometry and recent spectroscopic results. The photometric observations were made with the following telescopes: 1-m and 41-cm telescopes of Lulin Observatory (Taiwan), 81-cm telescope of Tenagra Observatory (Arizona, USA), 1-m telescope at the Mt. Lemmon Optical Astronomy Observatory (LOAO, Arizona, USA), 1.8-m and 15-cm telescopes at the Bohyunsan Optical Astronomy Observatory (BOAO, Korea) and 61-cm telescope at the Sobaeksan Optical Astronomy Observatory (SOAO, Korea). The observations span from 2010 to 2013, with ~200 to ~600 data points per light curve. Preliminary results of the Korean observations were presented at the 5th KASC workshop in Hungary. In this work, we analyze all observations. These observations permit the construction of full light curves for these RR Lyrae stars and can be used to derive multi-filter Fourier parameters.

scholarly journals Planets, candidates, and binaries from the CoRoT/Exoplanet programme

2018 ◽  
Vol 619 ◽  
pp. A97 ◽  
Author(s):  
M. Deleuil ◽  
S. Aigrain ◽  
C. Moutou ◽  
J. Cabrera ◽  
F. Bouchy ◽  
...  
Keyword(s):  
Major Axis ◽  
Space Mission ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Current Status ◽  
False Alarms ◽  
Semi Major Axis ◽  
Contact Binaries ◽  
Initial List

The CoRoT space mission observed 163 665 stars over 26 stellar fields in the faint star channel. The exoplanet teams detected a total of 4123 transit-like features in the 177 454 light curves. We present the complete re-analysis of all these detections carried out with the same softwares so that to ensure their homogeneous analysis. Although the vetting process involves some human evaluation, it also involves a simple binary flag system over basic tests: detection significance, presence of a secondary, difference between odd and even depths, colour dependence, V-shape transit, and duration of the transit. We also gathered the information from the large accompanying ground-based programme carried out on the planet candidates and checked how useful the flag system could have been at the vetting stage of the candidates. From the initial list of transit-like features, we identified and separated 824 false alarms of various kind, 2269 eclipsing binaries among which 616 are contact binaries and 1653 are detached ones, 37 planets and brown dwarfs, and 557 planet candidates. We provide the catalogue of all these transit-like features, including false alarms. For the planet candidates, the catalogue gives not only their transit parameters but also the products of their light curve modelling: reduced radius, reduced semi-major axis, and impact parameter, together with a summary of the outcome of follow-up observations when carried out and their current status. For the detached eclipsing binaries, the catalogue provides, in addition to their transit parameters, a simple visual classification. Among the planet candidates whose nature remains unresolved, we estimate that eight (within an error of three) planets are still to be identified. After correcting for geometric and sensitivity biases, we derived planet and brown dwarf occurrences and confirm disagreements with Kepler estimates, as previously reported by other authors from the analysis of the first runs: small-size planets with orbital period less than ten days are underabundant by a factor of three in the CoRoT fields whereas giant planets are overabundant by a factor of two. These preliminary results would however deserve further investigations using the recently released CoRoT light curves that are corrected of the various instrumental effects and a homogeneous analysis of the stellar populations observed by the two missions.

scholarly journals Using machine learning for transient classification in searches for gravitational-wave counterparts

2020 ◽  
Vol 497 (2) ◽  
pp. 1320-1331 ◽  
Author(s):  
Cosmin Stachie ◽  
Michael W Coughlin ◽  
Nelson Christensen ◽  
Daniel Muthukrishna
Keyword(s):  
Gravitational Wave ◽  
Classification Performance ◽  
Light Curves ◽  
Wide Field ◽  
Photometric Observations ◽  
Wide Field Of View ◽  
Astronomical Object ◽  
The Many ◽  
Rule Out

ABSTRACT The large sky localization regions offered by the gravitational-wave interferometers require efficient follow-up of the many counterpart candidates identified by the wide field-of-view telescopes. Given the restricted telescope time, the creation of prioritized lists of the many identified candidates becomes mandatory. Towards this end, we use astrorapid, a multiband photometric light-curve classifier, to differentiate between kilonovae, supernovae, and other possible transients. We demonstrate our method on the photometric observations of real events. In addition, the classification performance is tested on simulated light curves, both ideally and realistically sampled. We show that after only a few days of observations of an astronomical object, it is possible to rule out candidates as supernovae and other known transients.

scholarly journals Carnegie Supernova Project: Spectroscopic Observations of Core Collapse Supernovae

2011 ◽  
Vol 7 (S279) ◽  
pp. 361-362
Author(s):  
Nidia I. Morrell
Keyword(s):  
Optical Spectroscopy ◽  
Light Curves ◽  
Core Collapse ◽  
Type Ii ◽  
Spectroscopic Observations ◽  
Photometric Observations ◽  
Specific Analysis ◽  
Standard Candle ◽  
Distance Indicators

AbstractThe Carnegie Supernova Project (CSP) has performed, during the period 2004-2009, the optical and NIR follow up of 253 supernovae (SNe) of all types. Among those, 124 were core collapse events, comprising 93 SNe of type II and 31 of types Ib/Ic/IIb. Our follow up consisted of photometric observations suitable to build detailed light curves and a considerable amount of optical spectroscopy.The bulk of our observations is carried out at Las Campanas Observatory, while access to other facilities is also provided thanks to our strong collaboration with the Millennium Center for Supernova Studies (MCSS).Our spectroscopic observations were primarily aimed at typing possible new SNe, and follow-up the evolution of CSP targets. One of the goals of the follow-up of type II SNe is the application of independent distance indicators such as the Standard Candle (SCM) and the Expanding Photosphere (EPM) methods. Moreover, through the study of the spectroscopic evolution of these objects, from as early as possible after explosion to the nebular phases, we hope to contribute to their further understanding. Specific analysis of particular objects is underway by members of the CSP and an extended collaboration.

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