Data Set Information
|
| DATA_SET_NAME |
EPOXI 103P/HARTLEY2 ENCOUNTER - MRI PHOTOMETRY V1.0
|
| DATA_SET_ID |
DIF-C-MRI-5-EPOXI-HARTLEY2-PHOTOM-V1.0
|
| NSSDC_DATA_SET_ID |
|
| DATA_SET_TERSE_DESCRIPTION |
|
| DATA_SET_DESCRIPTION |
Data Set Overview : This dataset contains Clear1 filter (broadband, 200-1100 nm), CN (387 nm), OH (309 nm), C2 (514 nm), and dust continuum (Violet at 345 and Green at 526 nm) photometric measurements of comet 103/P Hartley 2 derived from reversibly-calibrated, radiance (RADREV) images acquired by the Medium Resolution Visible CCD (MRI) from 01 October through 26 November 2010, during the Hartley 2 encounter phase of the EPOXI mission. The heliocentric distance of the comet ranged from 1.12 to 1.06 AU. These photometry data were used by Bodewits, et al., 2013, [BODEWITSETAL2013] to characterize the gas and dust coma of Hartley 2. The photometry measurements and their computed errors are provided as 24, fixed-width, ASCII tables separated by filter and by photometry method. Two different methods were used: simple circular aperture photometry for radii of 1-30 pixels in 1-pixel increments and azimuthal averaged aperture photometry for 33 radii ranging from 1 to 248 pixels in graduated steps. The simple aperture photometry is robust for radii of 5 to 20 pixels while the azimuthal average method, which rejected stars, is recommended for analysis at larger apertures (radii of 20 or more pixels). The file naming convention for the data products is PhotMethod_DataType_FilterName.Ext where PhotMethod : APER for simple aperture photometry or AZAV for azimuthal average photometry DataType : PHOT for photometry measurements or ERR for computed errors FilterName : CLEAR1, CN, C2, OH, GREEN_CONT, or VIOLET_CONT Ext : TAB for a data table or LBL for the corresponding PDS label The first record in each data table lists the radii, in pixels, used to measure photometry. Subsequent records contain the measured photometry or computed errors; the columns in these records are: Col# Description (units) ---- ------------------------------------------------------------------ 1 MRI RADREV FITS image filename 2 Julian date for mid-obs 3 Day of year for 2010 4 Filter name 5 X-coordinate of originally measured centroid, where CCD vertical center : 255.5 (pixel) 6 Y-coordinate of originally measured centroid, where CCD horizontal center : 255.5 (pix) 7 Image size, both dimensions (pixel) 8 Horizontal distance of centroid to CCD vertical center line, where a negative value is left of that line (pixel) 9 Vertical distance of centroid to CCD horizontal center line, where a negative value is below that line (pixel) 10 Image quality flag, manually assigned 11* Target heliocentric distance* (AU) 12* Target-to-spacecraft distance* (km) 13* Phase angle, sun-target-spacecraft* (degree) 14 30 or 33 columns of photometric measurements or errors, corresponding to the aperture radii specified in the first table record. A value of -9.99E+03 indicates photometry could not be computed for the given aperture. (W/m^2/micron) * The geometry values in columns 11, 12, and 13 were extracted from the RADREV FITS image headers, which the EPOXI data pipeline computed at the epoch specified by the mid-obs time in column 2. Please read the accompanying report HARTLEY2_PHOTOMETRY_REPORT.PDF, which is located in the DOCUMENT directory. It thoroughly describes the photometry methods, error analysis and limitations, and it provides more detail about the MRI observations and frequency of filter usage.
|
| DATA_SET_RELEASE_DATE |
2012-12-15T00:00:00.000Z
|
| START_TIME |
2010-10-01T04:21:00.026Z
|
| STOP_TIME |
2010-11-26T03:59:35.642Z
|
| MISSION_NAME |
EPOXI
|
| MISSION_START_DATE |
2007-09-26T12:00:00.000Z
|
| MISSION_STOP_DATE |
2013-09-20T12:00:00.000Z
|
| TARGET_NAME |
103P/HARTLEY 2 (1986 E2)
|
| TARGET_TYPE |
COMET
|
| INSTRUMENT_HOST_ID |
DIF
|
| INSTRUMENT_NAME |
DEEP IMPACT MEDIUM RESOLUTION INSTRUMENT - VISIBLE CCD
|
| INSTRUMENT_ID |
MRI
|
| INSTRUMENT_TYPE |
CCD CAMERA
|
| NODE_NAME |
Small Bodies
|
| ARCHIVE_STATUS |
ARCHIVED
|
| CONFIDENCE_LEVEL_NOTE |
Confidence Level Overview : The data tables in this dataset were reviewed internally by the EPOXI project. Review : This dataset was certified for scientific use on 05 March 2013, during a peer review conducted by the PDS Small Bodies Node. Data Coverage and Quality : See the Data Set Overview above and the accompanying report DOCUMENT/HARTLEY2_PHOTOMETRY_REPORT.PDF. Limitations : See the accompanying report DOCUMENT/HARTLEY2_PHOTOMETRY_REPORT.PDF.
|
| CITATION_DESCRIPTION |
Williams, J.L., Li, J.-Y., Bodewits, D., and McLaughlin, S.A., EPOXI 103P/HARTLEY2 ENCOUNTER - MRI PHOTOMETRY V1.0, DIF-C-MRI-5-EPOXI-HARTLEY2-PHOTOM-V1.0, NASA Planetary Data System, 2012.
|
| ABSTRACT_TEXT |
This dataset contains clear-filter, CN, OH, C2, and dust-continuum photometric measurements of comet 103/P Hartley 2 derived from calibrated images acquired by the Medium Resolution Visible CCD (MRI) from 01 October through 26 November 2010, during the Hartley 2 encounter phase of the EPOXI mission. Two different methods were used: simple circular aperture photometry and azimuthal averaged aperture photometry, which removed stars. The results and uncertainties for both procedures are included in this dataset.
|
| PRODUCER_FULL_NAME |
STEPHANIE MCLAUGHLIN
|
| SEARCH/ACCESS DATA |
SBN Comet Website
|
|
.png)
.png)
