OBJECT = DATA_SET DATA_SET_ID = "IRTF-J/C-NSFCAM-3-RDR-SL9-V1.0" OBJECT = DATA_SET_INFORMATION DATA_SET_NAME = "IRTF NSFCAM Image Data from the SL9 Impact with Jupiter v1.0" DATA_SET_COLLECTION_MEMBER_FLG = "Y" START_TIME = 1994-01-05T10:36:34Z STOP_TIME = 1994-08-07T08:46:03Z DATA_SET_RELEASE_DATE = 1996-08-14 DATA_OBJECT_TYPE = IMAGE PRODUCER_FULL_NAME = "Dr. Mike A'Hearn" DETAILED_CATALOG_FLAG = "N" DATA_SET_DESC = " Data Set Overview ================= This file comprises notes from the primary archiving individuals giving relevant information about the contents, organization, instrumentation, and other information compiled during the archive process of IRTF data. This archive contains images of the P/SL-9 fragments pre-impact and the Jovian rings post-impact taken using the NASA/IRTF NSFCAM instrument. NSFCAM is a 256x256 InSb array with a variety of observing modes including imaging, polarimetry, and low-resoltuion grism spectroscopy. Plate scales of 0.3 arcseconds, 0.15 arcseconds, and 0.06 arcseconds are achieved with the 3-meter infrared IRTF telescope. (See the NSFCAM instrument description for details). Background ========== Image-Sky pairs are taken using a SUN system and an interactive real-time display; normally the data are stored with an OBJECT####.a filename for object images, and OBJECT####.b filenames for sky images. Details of the instrument settings during the observing run are found in the FITS header. Normalization of the observations is performed by dividing the image data by the product ITIME*CO_ADDS*NDR. Calibrations ============= Necessary for accurate photometric imaging are images of standard stars for absolute calibration. [The UKIRT Faint Standards are typically used; see the NASA IRTF home page URL for a listing of the stars and their magnitudes. Also required are images of the telescope dome interior with the dome lights on and off, used for flatfielding the array response. The observers M.A. A'Hearn, P.A. Esterle, and C.M. Lisse observed P/SL-9 and the Jovian system during 4 periods in 1994: Jan 5-7, May 11-12, July 12-19, and August 7; other observers participated and are listed separately. Processing ========== During the January and May observing runs, JHKK'-band (Johnson system) deep images of the P/SL-9 fragment train were obtained. The original logbook notes during the January and May observing runs are captured as TIFF files in the lognotes subdirectory. The May images were found to give better contrast of the debris train versus the sky; the Moon was full during the January observing and new during the May run. During the July 12-19 observations, images of a few individual fragments were obtained near to impact at J and K' (Orton et al., 1995. Science 267, 1277). (Due to Keplerian motion, the fragments had spread out greatly in angle on the sky near impact, so that only one fragment was available in the NSFCAM field of view). A possible observation of Fragment K within an hour of impact at K' was found instead to be a ghost image of a bright star created by the tilted filter. In August, JHK' observations of the Jovian ring system were made, to search for changes in the rings due to the dust input from the comet into the Jovian system (no obvious changes were found). Software ======== The NSFCAM data was processed by Phil Esterle at the University of Maryland using IDL. The data went through two distinct stages of analysis, the first of which (identified as original) is captured in the data directories. Data structure ============== SIMPLE = T / DATA IS IN FITS FORMAT BITPIX = 16 / 16 BITS TWOS COMPLEMENT INTEGERS NAXIS = 2 / NUMBER OF AXIS NAXIS1 = 256 / PIXELS ON 1st MOST VARYING AXIS NAXIS2 = 256 / PIXELS ON 2nd MOST VARYING AXIS DATAMIN = -7708 / MIN DATA VALUE IN FILE DATAMAX = 18777 / MAX DATA VALUE IN FILE DATAMEAN= 99 / MEAN DATA VALUE IN FILE ASEC_PIX= 0.30 / PLATE SCALE in arcseconds/pixel DIVISOR = 10 / Normalization value ORIGIN = 'Institute for Astronomy' TELESCOP= 'NASA IRTF' INSTRUME= 'NSFCAM, The Superhero Camera' OBSERVER= 'Your Name' OBJECT = 'Jupiter-Io-Europa' COMMENT = 'c flash-plume' IRAFNAME= 'data0882.a' BEAM = 'A' / Object(A) or sky(B) TIME_OBS= '07:40:22.02' / UT TIME OF ACQISTION ('hh:mm:ss.ss') DATE_OBS= '17/07/94' / UT DATE OF ACQUISITION ('dd/mm/yy ') ITIME = 0.0904 / INTEGRATION TIME IN SECONDS CO_ADDS = 10 / NUMBER OF INTEGRATIONS EXPOSURE= 0.9040 / combination of ITIME and CO_ADDS OBSMODE = 0 / obsmode is Obj(A) CYCLES = 1000 / Number of cycles SHIFTADD= 1 / Number of Actual Shift&Adds NUMARRAY= 1 / Number of Sub Arrays CAMMODE = Basic / Camera Mode SUBXEDGE= 0 SUBYEDGE= 0 COMMENT = 'ARRAY1 = 0,0,256,256 / x,y,wid,hgt of data array' COMMENT = 'SP_BINS = 38000,1000, / Speckle Peak,Binlen,Method' SAMPLES = 1 / Number of Samples CVF_WHEL= 5 / Name: Blocker Pos: 33605 FIL_WHEL= 17 / Name: H2(2-1)2.248 Pos: 5380 CVFWLEN = 2.2550 / CVF Wavelenght LEN = 1 / Name: 0.30 Pos: 2055 DIT = 0 / Name: Open Pos: 3750 PPLATE = 0 / P plate's Angel. Pos: 0 SAM_MODE= 2 / 1=SINGLE, 2=DOUBLE FRM_RATE= 1 / In msec. Fastmode=Off SlowCnt=1 Samples=1 RESET_MS= 1000 / Idle Resets in mseconds TEMP1 = 26.50 / Array Temperature TEMP2 = 76.60 / Coldbox Temperature TPD = ' 14:10:25.50 -11:57:42.9 02:47:46.54 1.615 1950.0 -O' RA = 14:10:25.50 / Right Ascension DEC = -11:57:42.9 / Declination HA = 02:47:46.54 / Hour Angle AIRMASS = 1.615 / Air Mass EPOCH = 1950.0 / Epoch VDDUC = -3.700 / Programmable voltage VVDUC VDET = -3.300 / Programmable voltage VDET END = / the end NB. The two lines captured in the COMMENT field and indicated by ticks are from the original FITS header; they do not follow the correct protocol as they sue multiple values separated by commas. By capturing the values in a comment, a FITS reader does not loose any information. Media/Format ============ This dataset is a CDWO submission to PDS. " CONFIDENCE_LEVEL_NOTE = "UNK" END_OBJECT = DATA_SET_INFORMATION OBJECT = DATA_SET_TARGET TARGET_NAME = JUPITER END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_TARGET TARGET_NAME = "SL9" END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_HOST INSTRUMENT_HOST_ID = IRTF INSTRUMENT_ID = NSFCAM END_OBJECT = DATA_SET_HOST OBJECT = DATA_SET_REFERENCE_INFORMATION REFERENCE_KEY_ID = "ORTONETAL1995" END_OBJECT = DATA_SET_REFERENCE_INFORMATION END_OBJECT = DATA_SET END