EPOXI MRI-VIS 103P/Hartley 2 Encounter Photometry Data Abstract ============= We perform photometric measurements of comet 103P/Hartley 2 using images taken through the CLEAR1 (broadband, 200-1100 nm), CN (387 nm), OH (309 nm), C2 (514 nm), and two continuum filters (Ultraviolet at 345 nm and Green at 526 nm) of the Medium Resolution Instrument (MRI) on board the Deep Impact flyby spacecraft from 1 October to 26 November 2010 during the EPOXI mission. Our analysis includes over 30,000 MRI science images where the nucleus was not resolved. We apply two different methods for our analysis: simple aperture photometry using circular apertures and azimuthally-averaged photometry using concentric annuli to remove stars. The resulting photometry and computed errors from each method are provided as separate ASCII tables along with PDS labels describing the layouts and columns. A comparison with DIF-C-MRI-5-EPOXI-HARTLEY2-PHOTOM-V1.0, Version 1 of this dataset, is given in Sec. 6 of epoxi_photometry_v5.pdf. Data Set Overview ================= We perform photometric measurements of comet 103P/Hartley 2 using images taken through the CLEAR1 (broadband, 200-1100 nm), CN (387 nm), OH (309 nm), C2 (514 nm), and two continuum filters (Ultraviolet at 345 nm and Green at 526 nm) of the Medium Resolution Instrument (MRI) on board the Deep Impact flyby spacecraft from 1 October to 26 November 2010 during the EPOXI mission. Our analysis includes over 30,000 MRI science images where the nucleus was not resolved. We apply two different methods for our analysis: simple aperture photometry using circular apertures and azimuthally-averaged photometry using concentric annuli to remove stars. The resulting photometry and computed errors from each method are provided as separate ASCII tables along with PDS labels describing the layouts and columns. The Medium Resolution Instrument consists of a Cassegrain telescope with a 12 cm aperture and a 2.1 m focal length and a CCD. The detector is a 1024x1024 split-frame, frame-transfer CCD with 21-micron-square pixels. The electronics allow readout of centered sub-frames in multiples of 2: 64x64, 128x128, and so on. The net pixel scale is 10 microradians/pixel (2.06 arcseconds/pixel). MRI images were never binned at Hartley 2. The full-width half-max (FWHM) of the point spread function is approximately 1.6 pixels (Klaasen et al., 2013). Our photometry process consists of the following steps: 1. Start with reversibly calibrated images and a list of comet centroid coordinates as the inputs 2. Assign a quality flag to each image 3. Remove cosmic rays 4. Apply the gap correction 5. Perform simple aperture photometry 6. Perform azimuthally averaged photometry 7. Compute photometric uncertainties We saved the results in 6 flat ASCII tables: 1. Azimuthally averaged surface brightness profiles 2. Error of surface brightness profiles 3. Small aperture photometry 4. Error of small aperture photometry 5. Large aperture photometry derived from profiles 6. Error of large aperture photometry The results are stored in separate files using an identical format, where every row contains the results for one image. For all 6 files, results are given for aperture radii/radial distances of [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 248] pixels. Invalid measurements (i.e. aperture photometry with r < 3 pixels or r > 20 pixels, and azimuthal profile integrals with r<10 pixels or r larger than the size of the detector) are labeled '-99' (we chose to include those so that all tables in this dataset have the same format). The tables all contain further information including the observing date, exposure time, the filter used, and the distances to the comet and Sun. The different columns contain the following information: Column Parameter Unit Comments 0 File name N/A 1 Julian Date UTC Midpoint of observation 2 DOY UTC Rounded to lowest integer 3 MRI Filter 4 X-position comet Pixels 5 Y-position comet Pixels 6 Exposure time Seconds 7 Frame size Pixels 8 X-distance comet Pixels Distance of comet centroid from horizontal boundary between CCD quadrants 9 Y-distance comet Pixels Distance of comet centroid from vertical boundary between CCD quadrants 10 Quality Flag Data with QF > 2 is excluded here. 0 = good; 1 = star nearby; 2 = cosmic ray nearby 11 Heliocentric distance AU 12 Spacecraft distance Km Distance to center of comet 13 Phase angle degrees Sun-comet-spacecraft angle 14 Solar elongation degrees Sun-spacecraft-comet angle 15 - 49 Flux W/m2^2/ Files 3 - 6. A value of -99 micrometer indicates photometry was not computed for the given aperture. 15 - 49 Surface Brightness W/m2^2/ Files 1 - 2. A value of -99 micrometer/sr indicates photometry was not computed for the given aperture. Please read the accompanying report epoxi_photometry_v5.pdf in the Documents directory for more detail. References ========== Belton, M.J.S., K.J, Meech, Karen, S. Chesley, et al., 2011, 'Stardust-NExT, Deep Impact, and the accelerating spin of 9P/Tempel 1', Icarus, Volume 213, Issue 1, p. 345-368, doi:10.1016/j.icarus.2011.01.006. Hampton, D.L., J.W. Baer, M.A. Huisjen, et al., 2005, An Overview of the Instrument Suite for the Deep Impact Mission, Space Science Reviews, 117, 43-93, doi:10.1007/s11214-005- 3390-8. Klaasen, K.P., M.F. A'Hearn, M. Baca, et al., 2008, Deep Impact Instrument Calibration, Rev. Sci. Instrum., 79, 091301, doi:10.1063/1.2972112. Klaasen, K.P., S. Besse, D. Bodewits, et al., 2013, EPOXI Instrument Calibration, Icarus 225, p643. McLaughlin, S.A., B. Carcich, S.E. Sackett, and K.P. Klaasen, 2012, Epoxi 103P/HARTLEY2 Encounter - MRI Calibrated Images V1.0, NASA Planetary Data System, DIF-C-MRI-3/4-EPOXI-HARTLEY2-V1.0, http://pdssbn.astro.umd.edu/holdings/dif-c-hriv- 3_4-epoxi-hartley2-v1.0.