Data Set Overview ================= This data set contains images of the Deep Space 1 target, comet 19P/Borrelly, and derived photometry from five consecutive nights of observing over 28 July - 1 August 2000. The observations were made using the 1.5m telescope of the Cerro Tololo Interamerican Observatory using the CFCCD camera mounted at the f/7.5 focus. The detector used was a Tek2K, yielding a plate scale of 0.4334 arcseconds/pixel. The photometric and lightcurve results were presented in Mueller and Samarasinha (2002). Parameters ========== The photometry, supplied as a single flat ASCII table, provides time, absolute R magnitude and an error bar for each image in the data set. Observational parameters for each image are incorporated into the PDS labels and FITS headers supplied with the data. Processing ========== The following description was extracted from Mueller and Samarasinha (2002). Additional details are provided in the published paper. All observations were made using a standard, broadband R filter. Integration time was limited to avoid tailing the comet image past the seeing disk. The IRAF package was used to bias-subtract and flat-field the images. Landolt stars (SA 112) were used for absolute calibration of the data from night four. Overlapping comparison stars in the comet fields between nights allowed the relative photometry of the other nights to be tied to the reference night (night four, 2000-07-31). Data ==== Images are supplied as FITS files with headers produced by the IRAF processing, with detached PDS labels generated by the Small Bodies Node. The photometry results are contained in a single, flat ASCII table. The data originally presented in the photometry table of Mueller and Samarasinha (2002) has been augmented with UTC date and start time, exposure time, airmass and a reference to the specific image file for each record. Note that there are two more lines in this photometry table than originally published in Mueller and Samarasinha (2002). The published table was truncated to fit the printed page. The final two lines have been restored in the electronic table. Also, not every image included in this collection has a corresponding line in the photometry table. When the comet was very close to a star, or when the photometric errors were too high, the image photometry was not included in the summary table. There are 334 images (comet and Landolt field) in this data set, of which 226 comet images are cited in the photometry table: Comet SA 112 Photometric Night Date Images Images Images ===== ========== ====== ====== =========== 1 2000-07-28 59 7 41 2 2000-07-29 46 10 39 3 2000-07-30 52 12 35 4 2000-07-31 64 10 53 5 2000-08-01 64 10 58 This table of geometric and observational circumstances for each night is reproduced from Mueller and Samarasinha (2002): Phase Heliocent. Geocent. Angle Sky Date dist. [AU] dist. [AU] [deg.] Condition ========== ========== ========== ====== ================== 2000-07-28 3.81 2.902 7.9 Not photometric 2000-07-29 3.80 2.902 8.1 Partly photometric 2000-07-30 3.80 2.901 8.3 Partly photometric 2000-07-31 3.79 2.902 8.4 Photometric 2000-08-01 3.79 2.902 8.6 Partly photometric Media/Format ============ The data are supplied as an electronic file in a PDS standard volume structure. Confidence Level Overview ========================= Explicit error bars are provided for the derived values of the absolute R magnitude. Standard techniques were used for the reduction of the image data and calculation of the photometry. See Mueller and Samarasinha (2002) for details of the image reduction and photometric calibration procedures. Review ====== This data set was reviewed in October 2003. References ========== Mueller, B.E.A. and N. Samarasinha, 2002, 'Visible Lightcurve Observations of Comet 19P/Borrelly', Earth, Moon and Planets, 90, 463-471.