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The Early Optical Brightening in the GRB 071010B

Description: We report the detection of early (60-230 s) optical emission of the gamma-ray burst afterglow of GRB071010B. No significant correlation with the prompt {gamma}-ray emission was found. Our high time-resolution data combining with other measurements within 2 days after the burst indicate that GRB071010B is composed of a weak early brightening ({alpha} {approx} 0.6), probably caused by the peak frequency passing through the optical wavelengths, followed by a decay ({alpha} {approx} -0.51), attributed to continuous energy injection by patchy jets.
Date: April 8, 2008
Creator: Wang, J H; Schwamb, M E; Huang, K Y; Wen, C Y; Zhang, Z W; Wang, S Y et al.
Partner: UNT Libraries Government Documents Department

Upper Limits on the Number of Small Bodies in Sedna-Like Orbits by the TAOS Project

Description: We present the results of a search for occultation events by objects at distances between 100 and 1000 AU in lightcurves from the Taiwanese-American Occultation Survey (TAOS). We searched for consecutive, shallow flux reductions in the stellar lightcurves obtained by our survey between 7 February 2005 and 31 December 2006 with a total of {approx} 4.5 x 10{sup 9} three-telescope simultaneous photometric measurements. No events were detected, allowing us to set upper limits on the number density as a function of size and distance of objects in Sedna-like orbits, using simple models.
Date: November 13, 2009
Creator: Wang, J; Lehner, M J; Zhang, Z; Bianco, F B; Alcock, C; Chen, W et al.
Partner: UNT Libraries Government Documents Department

The TAOS Project Stellar Variability II. Detection of 15 Variable Stars

Description: The Taiwanese-American Occultation Survey (TAOS) project has collected more than a billion photometric measurements since 2005 January. These sky survey data - covering timescales from a fraction of a second to a few hundred days - are a useful source to study stellar variability. A total of 167 star fields, mostly along the ecliptic plane, have been selected for photometric monitoring with the TAOS telescopes. This paper presents our initial analysis of a search for periodic variable stars from the time-series TAOS data on one particular TAOS field, No. 151 (RA = 17{sup h} 30{sup m} 6.67{sup s}, Dec = 27 degrees, 17 minutes, 30 seconds, J2000), which had been observed over 47 epochs in 2005. A total of 81 candidate variables are identified in the 3 square degree field, with magnitudes in the range 8 < R < 16. On the basis of the periodicity and shape of the lightcurves, 32 variables, 18 of which were previously unknown, are classified as RR Lyrae, Cepheid, {delta} Scuti, SX Phonencis, semi-regular and eclipsing binaries.
Date: January 28, 2010
Creator: Mondal, S; Lin, C C; Zhang, Z W; Alcock, C; Axelrod, T; Bianco, F B et al.
Partner: UNT Libraries Government Documents Department

Search for Small Trans-Neptunian Objects by the TAOS Project

Description: The Taiwan-America Occultation Survey (TAOS) aims to determine the number of small icy bodies in the outer reach of the Solar System by means of stellar occultation. An array of 4 robotic small (D=0.5 m), wide-field (f/1.9) telescopes have been installed at Lulin Observatory in Taiwan to simultaneously monitor some thousand of stars for such rare occultation events. Because a typical occultation event by a TNO a few km across will last for only a fraction of a second, fast photometry is necessary. A special CCD readout scheme has been devised to allow for stellar photometry taken a few times per second. Effective analysis pipelines have been developed to process stellar light curves and to correlate any possible flux changes among all telescopes. A few billion photometric measurements have been collected since the routine survey began in early 2005. Our preliminary result of a very low detection rate suggests a deficit of small TNOs down to a few km size, consistent with the extrapolation of some recent studies of larger (30-100 km) TNOs.
Date: December 4, 2006
Creator: Chen, Wen-Ping; Alcock, C.; Axelrod, T.; Bianco, F.B.; Byun, Y.I.; Chang, Y.H. et al.
Partner: UNT Libraries Government Documents Department