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15011. Supervised classification of CoRoT variables
ID:
ivo://CDS.VizieR/J/A+A/506/519
Title:
Supervised classification of CoRoT variables
Short Name:
J/A+A/506/519
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this work, we describe the pipeline for the fast supervised classification of light curves observed by the CoRoT exoplanet CCDs. We present the classification results obtained for the first four measured fields, which represent a one-year in-orbit operation. The basis of the adopted supervised classification methodology has been described in detail in a previous paper, as is its application to the OGLE database. Here, we present the modifications of the algorithms and of the training set, to optimize the performance when applied to the CoRoT data. Classification results are presented for the observed fields IRa01, SRc01, LRc01, and LRa01 of the CoRoT mission. Statistics on the number of variables and the number of objects per class are given and typical light curves of high-probability candidates are shown. We also report on new stellar variability types discovered in the CoRoT data. The full classification results are publicly available.
15012. Supervised classification of variable stars
ID:
ivo://CDS.VizieR/J/A+A/475/1159
Title:
Supervised classification of variable stars
Short Name:
J/A+A/475/1159
Date:
21 Oct 2021
Publisher:
CDS
Description:
The fast classification of new variable stars is an important step in making them available for further research. Selection of science targets from large databases is much more efficient if they have been classified first. Defining the classes in terms of physical parameters is also important to get an unbiased statistical view on the variability mechanisms and the borders of instability strips. Our goal is twofold: provide an overview of the stellar variability classes that are presently known, in terms of some relevant stellar parameters; use the class descriptions obtained as the basis for an automated `supervised classification' of large databases. Such automated classification will compare and assign new objects to a set of pre-defined variability training classes. For every variability class, a literature search was performed to find as many well-known member stars as possible, or a considerable subset if too many were present. Next, we searched on-line and private databases for their light curves in the visible band and performed period analysis and harmonic fitting. The derived light curve parameters are used to describe the classes and define the training classifiers. We compared the performance of different classifiers in terms of percentage of correct identification, of confusion among classes and of computation time. We describe how well the classes can be separated using the proposed set of parameters and how future improvements can be made, based on new large databases such as the light curves to be assembled by the CoRoT and Kepler space missions. The derived classifiers' performances are so good in terms of success rate and computational speed that we will evaluate them in practice from the application of our methodology to a large subset of variable stars in the OGLE database and from comparison of the results with published OGLE variable star classifications based on human intervention. These results will be published in a subsequent paper.
15013. SuperWASP exoplanetary transit survey
ID:
ivo://CDS.VizieR/J/MNRAS/372/1117
Title:
SuperWASP exoplanetary transit survey
Short Name:
J/MNRAS/372/1117
Date:
21 Oct 2021
Publisher:
CDS
Description:
Photometric transit surveys promise to complement the currently known sample of extra-solar planets (ESPs) by providing additional information on the planets and especially their radii. Here, we present ESP candidates from one such survey called, the Wide Angle Search for Planets (WASP) obtained with the SuperWASP wide-field imaging system. Observations were taken with SuperWASP North located in La Palma during the 2004 April to October observing season. The data cover fields between 23 and 03h in RA at declinations above +12{deg}. This amounts to over >>400000 stars with V magnitudes 8-13.5. For the stars brighter than 12.5, we achieve better than 1% photometric precision. Here, we present 41 sources with low-amplitude variability between >>1 and 10mmag, from which we select 12 with periods between 1.2 and 4.4d as the most promising ESP candidates. We discuss the properties of these ESP candidates, the expected fraction of transits recovered for our sample and implications for the frequency and detection of hot-Jupiters.
15014. SuperWASP-North extrasolar planet candidates
ID:
ivo://CDS.VizieR/J/MNRAS/379/816
Title:
SuperWASP-North extrasolar planet candidates
Short Name:
J/MNRAS/379/816
Date:
21 Oct 2021
Publisher:
CDS
Description:
The SuperWASP-I (Wide Angle Search for Planets-I) instrument observed 6.7 million stars between 8 and 15mag from La Palma during the 2004 May-September season. Our transit-hunting algorithm selected 11626 objects from the 184442 stars within the RA (right ascension) range 18-21h. We describe our thorough selection procedure whereby catalogue information is exploited along with careful study of the SuperWASP data to filter out, as far as possible, transit mimics. We have identified 35 candidates which we recommend for follow-up observations.
15015. SuperWASP-North extrasolar planet candidates
ID:
ivo://CDS.VizieR/J/MNRAS/379/647
Title:
SuperWASP-North extrasolar planet candidates
Short Name:
J/MNRAS/379/647
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have performed photometric observations of nearly seven million stars with 8<V<15 with the SuperWASP-North instrument from La Palma between 2004 May to September. Fields in the right ascension range 17-18h, yielding over 185000 stars with sufficient quality data, have been searched for transits using a modified box least-squares (BLS) algorithm. We find a total of 58 initial transiting candidates which have high signal-to-noise ratio in the BLS, show multiple transit-like dips and have passed visual inspection. Analysis of the blending and the inferred planetary radii for these candidates leave, a total of seven transiting planet candidates which pass all the tests plus four which pass the majority. We discuss the derived parameters for these candidates and their properties and comment on the implications for future transit searches.
15016. SuperWASP-North extrasolar planet candidates
ID:
ivo://CDS.VizieR/J/MNRAS/384/1097
Title:
SuperWASP-North extrasolar planet candidates
Short Name:
J/MNRAS/384/1097
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Wide Angle Search for Planets (WASP) survey currently operates two installations, designated SuperWASP-N and SuperWASP-S, located in the Northern and Southern hemispheres, respectively. These installations are designed to provide high time-resolution photometry for the purpose of detecting transiting extrasolar planets, asteroids, and transient events. Here, we present results from a transit-hunting observing campaign using SuperWASP-N covering a right ascension (RA) range of 06h<RA<16h. This paper represents the fifth and final in the series of transit candidates released from the 2004 observing season. In total, 729335 stars from 33 fields were monitored with 130566 having sufficient precision to be scanned for transit signatures. Using a robust transit detection algorithm and selection criteria, six stars were found to have events consistent with the signature of a transiting extrasolar planet based on the photometry, including the known transiting planet XO-1b. These transit candidates are presented here along with discussion of follow-up observations and the expected number of candidates in relation to the overall observing strategy.
15017. SuperWASP-North extrasolar planet candidates
ID:
ivo://CDS.VizieR/J/MNRAS/381/851
Title:
SuperWASP-North extrasolar planet candidates
Short Name:
J/MNRAS/381/851
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Wide Angle Search for Planets (WASP) photometrically surveys a large number of nearby stars to uncover candidate extrasolar planet systems by virtue of small-amplitude light curve dips on a <=5d time-scale typical of the 'Hot-Jupiters'. Observations with the SuperWASP-North instrument between 2004 April and September produced a rich photometric data set of some 1.3x10^9^ data points from 6.7 million stars. Our custom-built data acquisition and processing system produces ~0.02mag photometric precision at V=13. We present the transit candidates in the 03h-06h RA range. Out of 141895 light curves with sufficient sampling to provide adequate coverage, 2688 show statistically significant transit-like periodicities. Out of these, 44 pass a visual inspection of the light curve, of which 24 are removed through a set of cuts on the statistical significance of artefacts. All but four of the remaining 20 objects are removed when prior information at higher spatial resolution from existing catalogues is taken into account. Of the four candidates remaining, one is considered a good candidate for follow-up observations with three further second-priority targets. We provide detailed information on these candidates, as well as a selection of the false-positives and astrophysical false-alarms that were eliminated, and discuss briefly the impact of sampling on our results.
15018. SuperWASP observations of pulsating Am stars
ID:
ivo://CDS.VizieR/J/A+A/535/A3
Title:
SuperWASP observations of pulsating Am stars
Short Name:
J/A+A/535/A3
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have studied over 1600 Am stars at a photometric precision of 1mmag with SuperWASP photometric data. Contrary to previous belief, we find that around 200 Am stars are pulsating delta Sct and gamma Dor stars, with low amplitudes that have been missed in previous, less extensive studies. While the amplitudes are generally low, the presence of pulsation in Am stars places a strong constraint on atmospheric convection, and may require the pulsation to be laminar. While some pulsating Am stars have been previously found to be delta Sct stars, the vast majority of Am stars known to pulsate are presented in this paper. They will form the basis of future statistical studies of pulsation in the presence of atomic diffusion.
15019. SuperWASP/ROSAT periodic variable stars
ID:
ivo://CDS.VizieR/J/A+A/467/785
Title:
SuperWASP/ROSAT periodic variable stars
Short Name:
J/A+A/467/785
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present optical lightcurves of 428 periodic variable stars coincident with ROSAT X-ray sources, detected using the first run of the SuperWASP photometric survey. Only 68 of these were previously recognised as periodic variables. A further 30 of these objects are previously known pre-main sequence stars, for which we detect a modulation period for the first time. Amongst the newly identified periodic variables, many appear to be close eclipsing binaries, their X-ray emission is presumably the result of RS CVn type behaviour. Others are probably BY Dra stars, pre-main sequence stars and other rapid rotators displaying enhanced coronal activity. A number of previously catalogued pulsating variables (RR Lyr stars and Cepheids) coincident with X-ray sources are also seen, but we show that these are likely to be misclassifications. We identify four objects which are probable low mass eclipsing binary stars, based on their very red colour and light curve morphology.
15020. SuperWASP short period eclipsing binaries
ID:
ivo://CDS.VizieR/J/A+A/528/A90
Title:
SuperWASP short period eclipsing binaries
Short Name:
J/A+A/528/A90
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present light curves and periods of 53 candidates for short period eclipsing binary stars identified by SuperWASP. These include 48 newly identified objects with periods <2x10^4^s (~0.23d), as well as the shortest period binary known with main sequence components (GSC2314-0530 = 1SWASP J022050.85+332047.6) and four other previously known W UMa stars (although the previously reported periods for two of these four are shown to be incorrect). The period distribution of main sequence contact binaries shows a sharp cut-off at a lower limit of around 0.22d, but until now, very few systems were known close to this limit. These new candidates will therefore be important for understanding the evolution of low mass stars and to allow investigation of the cause of the period cut-off.

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