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Recovery of comet 85P/Boethin for the Deep Impact Extended Mission
Project Investigators: Karen Meech, Jan Kleyna
Summary
We developed new image stacking techniques to attempt to recover comet 85P/Boethin as a target for the NASA EPOXI mission (retargeting of the Deep Impact probe). We were unable to recover Boethin using many nights of observations from the CFHT, Subaru, VLT, and Gemini telescopes. We found one candidate, but it was not deemed certain enough to justify retargeting EPOXI. At the time of this writing, the object has not been recovered, suggesting it may have broken up.
Astrobiology Roadmap Objectives:
Project Progress
The Deep Impact Extended Mission was the planned retargeting of the Deep Impact probe to visit comet 85P/Boethin. A crucial first step to the mission was the recovery of 85P, in order to make the necessary course corrections for the flyby. We have been working on image data processing and analysis for the Deep Impact recovery.
We obtained extensive imaging along 85P’s line of variations (LOV) using the half-degree field Suprime-Cam CCD array on the Subaru telescope, the one degree CFHT Megacam camera, and smaller fields using Gemini GMOS and the ESO VLT. Combining images on this large scale is complex, necessitating the removal of significant optical distortions, the computation of precise global coordinates, and the combination of the chip array into a global image, including static sky subtraction and star-masking. We have written specialized software to accomplish these tasks.
Because the LOV covers a large fraction of a degree on the sky, the location of the comet is poorly constrained. More crucially for the image stacking needed to detect a faint object, the comet’s point in its orbit, and thus its velocity, are poorly constrained as well. Thus it is impossible to stack the images at a fixed rate, which is valid only for one possible position on the LOV. Accordingly, we have developed a novel stacking approach that effectively distorts each image in a manner that maps the LOVs from different images onto each other using a global coordinate transformation, ensuring that the comet is detected regardless of its position along the LOV. We have also developed a novel “DNA banding” method to translate and juxtapose the LOV from different telescopes, to see if a band consistent with several low-significance detections of the comet is visible.
Stacked image of our CFHT observations, with the line of variations running between the double rows of artificial calibration images. The circle shows our low significance candidate object.Figure 1 shows our low-significance stacked CFHT detection of a candidate, with synthetic objects for stacking verification; and Figure 2 shows a DNA band map from several telescopes.
This image processing project failed to find 85P/Boethin, although its validity was demonstrated by detecting other objects moving at close to Boethin’s rate. Boethin has not been recovered near its expected location this year, supporting our tentative conclusion that it has broken up.
'DNA band' approach to recovering Boethin. Each band is the collapsed line of variations from a particular observing run. A genuine candidate should show as a bright band in each run. The candidate of Figure 1 shows up as such a band in some but not all runs.Mission Involvement
EPOXIRecovery attempt of 85P/Boethin to be EPOXI mission target.
- HANDBOOK OF STAR FORMING REGIONS
- A Rare low mass quadruple spectroscopic AND eclipsing binary
- A search for Main Belt Comets in Pan-STARRS 1
- A search for primordial water from deep in the Earth's mantle
- A spectroscopically unique Main Belt asteroid: 10537 (1991 RY16)
- A Supertree Analysis of the Metazoan Phylogeny
- Acquisition and Installation of a new Cameca ims 1280 ion microprobe
- Acquisition and Installation of Witec Confocal Raman microscope scanning system
- Amorphization of Crystalline Water Ice in the Solar System
- Assessing the likelihood of supernova impact of protoplanetary disks
- Carbonate Lithologies on Devon Island, Canada
- Chemistry and biology of ultramafic-hosted alkaline springs
- Chemistry of the NH3/H2O system
- DIVERSITY AND BIOGEOGRAPHY OF THE UNIQUE TROPICAL PHYLUM PLACOZOA
- Dynamical Evolution of Astroid Belt and the Parent Bodies of Iron Meteorites
- Ecology of a Hawaiian lava cave microbial mat
- FMARS Long Duration Mission: a simulation of manned Mars exploration in an analogue environment, Devon Island, Canada
- Formation and Detection of Hot-Earth Objects in Systems with Close-in Jupiters
- Formation and the Prospects of the Detection of Habitable Planets in Extreme Planetary Systems
- Formation of Molecular Hydrogen via Interaction of Ionizing Radiation with Hydrocarbon Ices in the Interstellar Medium
- Formation of Planetesimals in a Dynamically Evolving Nebula
- FU ORIONIS ERUPTIONS
- Ice Ages on Mars
- Ice at the Mars Phoenix Landing Site
- Ice on Main Belt Comets
- Icelandic subglacial lakes
- Mechanisms of Marine Microbial Community Structuring
- Mechanistical Studies on the Non-Equilibrium Chemistry of Unusual Carbon Oxide in Solar System Ices
- Modeling grain surface reaction pathways for large organic molecules
- Molecular Deuteration on grain surfaces
- NEWBORN BINARIES
- Observations and Models of comet 17P/Holmes
- Origin and Activation Mechanism of Main Belt Comets
- Origin of Irregular Satellites
- Recovery of comet 85P/Boethin for the Deep Impact Extended Mission
- Sediment-buried basement deep biosphere
- Serpentinazation and abiogenic methane in the Mariana Forearc
- Sleeping through the Arctic Martian Sol
- Spectropolarimetric studies of stars with hot jupiters
- TES study of intracrater low albedo deposits, Amazonis Planitia, Mars
- The delivery of short-lived radionucleides to the solar system
- The effect of lunar-like satellites on the orbital infrared lightcurves of Earth-analog planets
- The Main Belt distribution of basaltic asteroids
- The Size Distribution of Small KBOs
- THE VYSOS PROJECT
- Ultra-violet processing of ices in the Rosette Nebula
- Unveiling the evolution and interplay of ice and gas in quiescent clouds
- Variable Young Stellar Objects Survey (VYSOS)
- Water on Mars
- X-ray- and UV-bright low-mass stars in the solar neighborhood