Data Set Overview : This data set contains a clear-filtered High Resolution Visible CCD (HRIV) point spread function (PSF) for exoplanet transit targets GJ 436, HAT-P-4, HAT-P-7, TrES-2, TrES-3, XO-2, and XO-3 as well as PSFs for the HRIV PSF for stellar calibrator targets for the EPOXI mission. The PSFs were produced by applying the drizzle method described by Fruchter and Hook, 2002, [FRUCHTER&HOOK2002] to sets of HRIV images of the targets acquired during 2008. A PSF for transit target WASP-3 was not produced due to a crowded star field.  The EPOXI mission observes the transits of exoplanets, Earth and Mars, and a comet nucleus using the HRIV CCD on board the Deep Impact flyby spacecraft (DIF). However the 0.3-m f/35 High Resolution telescope is permanently defocused by 0.6 cm. Consequently the point spread function for the HRIV instrument covers approximately nine pixels at full-width half-max and is characterized by a patch with three-fold symmetry (six points) due to the three-point support structures of the primary and secondary mirrors. The resulting PSF is also strongly dependent on color, varying in shape and size with respect the HRIV filter being used and the color of the target. Therefore all resolved HRIV images analyzed for the mission should be deconvolved with one of the instrument PSFs provided in the data sets. The HRIV PSFs in this data set were also used to optimize exoplanet transit analysis for the EPOXI mission.  The PSFs are provided as 2-dimensional FITS images by target and filter when applicable. The 'Development and Utilization of the HRIV Point Spread Function for the EPOXI Mission' report included in this data set describes how the PSFs for the stellar calibrators and exoplanet transit targets were constructed for and utilized by the EPOXI team. (Or see Barry, et al., 2010 [BARRYETAL2010].)  The following PDS data sets, available online at http://pds.nasa.gov, are related to this one and may be useful for research:  DIF-X-HRIV-3-EPOXI-EXOPLANETS-V1.0 - Radiance calibrated HRIV extrasolar planet transit observations GJ 436, HAT-P-4, HAT-P-7, TRES-2, TRES-3, WASP-3, XO-2, and XO-2 acquired during 2008; The EPOCh team used subsets of the reversibly calibrated images (known as 'RADREV') in this data set to construct PSFs.  DIF-CAL-HRIV-2-EPOXI-CALIBRATIONS-V1.0 - Raw in-flight HRIV calibrations including the stellar calibrators 16 Cyg A, Achernar, Beta Hyi, Canopus, HD 60753, HD 79447, and Vega; The EPOCh team used reversibly calibrated subsets of these raw data to construct PSFs.  DIF-X-HRIV-5-EPOXI-EXOPLANETS-PHOT-V1.0 - HRIV photometry (light curves) of the transiting planet systems observed by EPOXI.  DI-C-HRII/HRIV/MRI/ITS-6-DOC-SET-V3.0 - Deep Impact and EPOXI documentation set provides overviews of the EPOXI mission.

Confidence Level Overview : The EPOXI/EPOCh team applied the PSF data files in this data set to their analysis of exoplanet transit targets and resulting photometry.  Review : This data set was peer reviewed at the PDS Small Bodies Node (SBN) and certified for archiving on 29 September 2010 pending the resolution of liens. Liens were resolved in December 2010. This data set is archived at SBN and and the Multi-Mission Archive at STScI (MAST).  Data Coverage and Quality : The EPOXI/EPOCh team did not construct a PSF for transit target WASP-3 due to a crowded star field. The EPOXI team recommends using one of the PSFs for a calibrator star when working with WASP-3 images.  Limitations :  HRI Telescope Focus ------------------- Images of stars acquired early during the Deep Impact mission in 2005 indicated the HRI telescope was out of focus. In-flight bakeouts during late February and early March 2005 reduced the defocus from about 1.0 cm to about 0.6 cm, resulting in a decrease in the width of stars from about 12 pixels to 9 pixels. For more details, please see the Deep Impact instrument calibration paper by Klaasen, et al. (2008) [KLAASENETAL2006] and the Deep Impact image restoration paper by Lindler, et al. (2007) [LINDLERETAL2007].