PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT NOTE = "AAREADME file for Borrelly earth based images" PUBLICATION_DATE = 2007-06-25 END_OBJECT = TEXT END *** NOTE: The Version 1 delivery volume of this data set was discovered *** to contain corrupted FITS files in the data/ directory. This *** was corrected and a second version of the delivery volume *** created and submitted to PDS Engineering Node and the NSSDC *** in July 2007. This data set collection contains earth-based images of comet Borrelly. The images included here were obtained at the McDonald Observatory on five different observing runs during the 2001 apparition: 21-23 Sep 2001 12 Nov 2001 04-07 Dec 2001 07-08 Feb 2002 17-18 May 2002 The December data were obtained at the 2.1-m Otto Struve telescope and the data from the other four runs were obtained at the 2.7-m Harlan J. Smith telescope. In both cases, the Imaging Grism Instrument (IGI), a 5:1 focal reducer and a TeK 1024x1024 CCD were used. On the 2.7-m telescope, this configuration produces a vignetted field of view with 0.57 arcsec pixels. On the 2.1-m the field of view is 6 arcmin, with 0.48 arcsec pixels. On almost all nights, both broadband V and R filters were used. (On 7 Dec and 17 May, only R images were obtained.) On photometric nights, Landolt standard stars were observed at several airmasses to provide a measurement of the extinction and a means of obtaining an absolute calibration. There are four data directories. The first (BASIC) contains about 160 files which are bias subtracted, flat fielded images of comet Borrelly from all of the observing runs. The second (STANDARDS) contains about 100 images of standard star fields that are used to calibrate the data. The third directory (CALIBRATED) includes all of the calibrated images (images from nights where standard stars were obtained). The calibrated images are a subset of the images in the basic directory. The fourth directory (PROCESSING) contains the bias frames and the flat field images that were used to process the data. The filenames contain the date and filter information for which they were used. All of the data files are in FITS format. An extensive discussion of the data can be found in Farnham, T.L. and A.L. Cochran, 'A McDonald Observatory Study of Comet 19P/Borrelly: Placing the Deep Space 1 Observations into a Broader Context', Icarus, 160, 398-418, 2002 This description was written by Tony L. Farnham Questions regarding the scientific elements of the data set: Tony Farnham Small Bodies Node, Planetary Data System Department of Astronomy, University of Maryland College Park, MD 20742-2421 farnham@astro.umd.edu Questions regarding PDS elements of the data set: raugh@astro.umd.edu