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Detection of Potential Transit Signals in the First Three Quarters of Kepler Mission Data
We present the results of a search for potential transit signals in thefirst three quarters of photometry data acquired by the Kepler mission.The targets of the search include 151,722 stars which were observed overthe full interval and an additional 19,132 stars which were observed foronly one or two quarters. From this set of targets we find a total of5392 detections which meet the Kepler detection criteria: those criteriaare periodicity of signal, an acceptable signal-to-noise ratio, and acomposition test which rejects spurious detections which containnon-physical combinations of events. The detected signals are dominatedby events with relatively low signal-to-noise ratio and by events withrelatively short periods. The distribution of estimated transit depthsappears to peak in the range between 40 and 100 parts per million, witha few detections down to fewer than 10 parts per million. The detectionsexhibit signal-to-noise ratios from 7.1σ, which is the lowercutoff for detections, to over 10,000σ, and periods ranging from0.5 days, which is the lower cutoff used in the procedure, to 109 days,which is the upper limit of achievable periods given the length of thedata set and the criteria used for detections. The detected signals arecompared to a set of known transit events in the Kepler field of viewwhich were derived by a different method using a longer data interval;the comparison shows that the current search correctly identified 88.1%of the known events. A tabulation of the detected transit signals,examples which illustrate the analysis and detection process, adiscussion of future plans and open, potentially fruitful, areas offurther research are included.
| Corrections to the Hipparcos Proper Motions in Declination for 807 Stars
We used the data on latitude variations obtained from observations with10 classical photographic zenith tubes (PZT) in order to improve theHipparcos proper motions in declinations ?_{?} for 807 stars.Part of observing programmes, carried out during the last century forthe purpose of studying the Earth's rotation, were realized by using PZTinstruments. These observations were performed within in the intervals(tens of years) much longer than that of the Hipparcos mission (lessthan 4 years). In addition, the annual number of observations for everyPZT-programme star is several hundreds on the average. Though theaccuracy of the star coordinates in the Hipparcos Catalogue is by twoorders of magnitude better than that of the star coordinates from thePZT observations, the large number of observations performed a muchlonger time interval makes it possible to correct the Hipparcos propermotions and to improve their accuracy with respect to the accuracy givenin the Hipparcos Catalogue. Long term examinations of latitude and timevariations were used to form the Earth Orientation Catalogue (EOC-2),aimed at a more accurate determination of positions and proper motionsfor the stars included. Our method of calculating the corrections of theproper motions in declination from the latitude variations is differentfrom the method used in obtaining the EOC-2 Catalogue. Comparing theresults we have established a good agreement between our ?_{?}and the EOC-2 ones for the star sample used in the present paper.
| The Tokyo PMC catalog 90-93: Catalog of positions of 6649 stars observed in 1990 through 1993 with Tokyo photoelectric meridian circle
The sixth annual catalog of the Tokyo Photoelectric Meridian Circle(PMC) is presented for 6649 stars which were observed at least two timesin January 1990 through March 1993. The mean positions of the starsobserved are given in the catalog at the corresponding mean epochs ofobservations of individual stars. The coordinates of the catalog arebased on the FK5 system, and referred to the equinox and equator ofJ2000.0. The mean local deviations of the observed positions from theFK5 catalog positions are constructed for the basic FK5 stars to comparewith those of the Tokyo PMC Catalog 89 and preliminary Hipparcos resultsof H30.
| UBV photometry of stars whose positions are accurately known. III
UBV photometric observations of 417 stars at BD declination 35-49 degfrom the NPZT(74) catalog of Yasuda et al. (1982) and the AGK3R catalogof Corben (1978), obtained with the 40-cm Cassegrain reflector atKvistaberg Observatory during 1984-1985, are reported. The data arepresented in tables, and the mean errors per observation are given as0.016 mag in V, 0.011 mag in B-V, 0.012 mag in U-B for U less than 10,and 0.026 mag in U-B for U greater than 10.
| Photoelectric UBV photometry for 317 PZT and VZT stars
UBV data were taken of 317 stars to fill gaps in photoelectric recordsneeded for establishing a terrestrial reference frame for earthorientation purposes. The study supplied the magnitudes and colors andaided in identifying nearby stars without trigonometric parallaxes. Thesurvey averaged over three observations of each object. A complete tableof the V, B-V, U-B and number of observations of each object isprovided.
| Preliminary catalog of the declinations of 96 stars of the international program, compiled from Kitab PZT observations
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