DPS 42nd Meeting Abs..

28.19: Observaons Of Comet C/2007 (lulin) Before And During Its PerihelionAuthor Block: Gian-Paolo Tozzi 1 , J. R. Brucato 1 , P. Patriarchi 1 , J. Licandro 2 , E. Mazzoa Epifani 3 , C. Snodgrass 4 , J. Vincent 41 INAF Osservatorio Astrofisico di Arcetri, Italy, 2 IAC, Spain, 3 INAF, Italy, 4 M PS, Germany.Presentaon Time: 10/4/2010 4:36 PM - 4:38 PMLocaon: Exhibit HallAbstract.Abstract: Comet Lulin was observed in July 2008, when the comet was in-bound at 1.7 AU from the Sun. Analysis of the images showed that the comethad a very intense and anomalous enhancement of the column density of the solid components in the inner coma. This effect was before interpreted as due tothe presence of sublimang grains (Tozzi et al, 2004, AA, 424, 325; 2007, 476, 979) or, more recently, to a developing coma expanding very slowly (few meters persecond, Tozzi et al. 2010, submied). To disentangle the two phenomena the comet was re-observed in two epochs around its perihelion (Jan - Mar. 2009), whenit was at about 1.40 AU from the Sun and at about 0.4 AU from the Earth. In this case the enhancement in the inner coma had disappeared, showing only a widebut less intense enhancement at about 20000-30000 km of projected distance. A possible contaminaon of gas, that would produce a similar effect, has beenexcluded by spectra and observaons with narrow band filters centred in spectral regions without gas emission. In the presentaon the results of the analysiswith possible interpretaons will be given.28.20: A Study of Water in Comet C/2007 N3 (Lulin)Author Block: Emily Sudholt 1 , B. P. Bonev 2 , E. L. Gibb 1 , M. A. DiSan 3 , G. Villanueva 3 , M. J. Mumma 3 , K. Magee-Sauer 41 University of Missouri - St. Louis, 2 Catholic University of America, 3 NASA Goddard Space Flight Center, 4 Rowan University.Presentaon Time: 10/4/2010 4:38 PM - 4:40 PMLocaon: Exhibit HallAbstract: We conducted a sensive search for HDO and detected H 2 O and OH in the spectra of comet C/2007 N3 (Lulin) obtained by NIRSPEC at the Keck IItelescope atop Mauna Kea, Hawaii. OH prompt emission is a direct proxy of H 2 O producon and eliminates “inter-seng” calibraon uncertaines in evaluangthe HDO/H 2 O rao. We report an upper limit for HDO/H 2 O, and spaal profiles, rotaonal temperatures, and producon rates for H2O. The work ofundergraduate student E. Sudholt was supported over 12 months by NSF Grant AST- 0807939 (PI/Co-PI Bonev/Gibb) and by the Goddard Center for Astrobiology (PIMumma). Co-authors gratefully acknowledge support from the NSF Astronomy and Astrophysics Research Grants Program, and by the NASA’s PlanetaryAstronomy, Planetary Atmospheres, and Astrobiology Programs.28.21: Detecons of Ethane (C 2 H 6 ), Methane (CH 4 ), and Carbon Monoxide (CO) in the Coma of Comet C/2006 W3 (Christensen) at 3.25 AU from The SunAuthor Block: Boncho Bonev 1 , H. Böhnhardt 2 , M. J. Mumma 3 , M. A. DiSan 3 , G. L. Villanueva 1 , M. Lippi 2 , E. L. Gibb 41 The Catholic Univ. of America / Goddard Center for Astrobiology, 2 Max-Planck Instute for Solar System Research, Germany, 3 NASA Goddard Space FlightCenter / Goddard Center for Astrobiology, 4 Univ. of Missori - St. Louis / Goddard Center for Astrobiology.Presentaon Time: 10/4/2010 4:40 PM - 4:42 PMLocaon: Exhibit HallAbstract: We report high-resoluon spectroscopic observaons of comet C/2006 W3 (Christensen) using the Cryogenic Infrared Echelle Spectrograph at theVery Large Telescope Observatory atop Cerro Paranal, Chile. We detected the “hypervolales” C 2 H 6 , CH 4 , and CO in the coma observed at heliocentric distance of3.25 AU. We also detected CO at 4.03 AU from the Sun. This presentaon will report spaal profiles, rotaonal temperature, and producon rates of the threedetected species. We compare our results with the radio detecon of CO (Bockelee-Morvan et al. A&A, 518, L149) and other parent volales at 3.20 and 3.32 AUto achieve an overall measure of the volale composion of this comet. The apparent enrichment in the coma of “hypervolales” will be discussed in terms offraconaon of nave ices within the nucleus. We gratefully acknowledge support from the NSF Astronomy and Astrophysics Research Grants Program (PI/co-PIBonev/Gibb), by the NASA’s Planetary Astronomy (PI Mumma; PI DiSan), Planetary Atmospheres (PI DiSan; PI Villanueva), and Astrobiology (PI Mumma)Programs, and by the German-Isreal Foundaon for Scienfic Research and Development (PI Böhnhardt).28.22: The Molecular Composion of Comet C/2007 W1 (Boani): Evidence of a Peculiar Outgassing and Rich ChemistryAuthor Block: Geronimo Villanueva 1 , M. A. DiSan 1 , M. J. Mumma 1 , B. P. Bonev 2 , E. L. Gibb 3 , K. Magee-Sauer 4 , G. A. Blake 51 NASA's GSFC, 2 Catholic University of America, 3 University of Missouri, 4 Rowan University, 5 Caltech.Presentaon Time: 10/4/2010 4:42 PM - 4:44 PMLocaon: Exhibit HallAbstract.Abstract: We report observaons of comet C/2007 W1 (Boani) performed using the long-slit high-resoluon echelle grang spectrograph at Keck-2(NIRSPEC) on July 9 and 10 of 2008. We present results for 10 volale species (H2O, OH*, C2H6, CH3OH, H2CO, CH4, HCN, C2H2, NH3, CO), the ortho-para raosof H2O and CH4, and an upper-limit of the water D/H rao in comet Boani. We observe important differences in the spaal profiles of the detected species,with the majority of the polar volales showing very asymmetric profiles. We present emission profiles for all observed volales along the cometary coma anddiscuss different producon scenarios necessary to explain these. Ulmately, we compare all measured cosmogonic indicators and relate these to a possibleformaon path for this comet. We acknowledge support from the NASA Planetary Atmospheres, Planetary Astronomy, Astrobiology Programs, and the NSFAstronomy and Astrophysics Research Grants Program.28.23: Searching for Gas Emission through Visible Spectroscopy of Large Perihelia (>5AU) CometsAuthor Block: Sean Mossman 1 , L. M. Woodney 1 , Y. R. Fernandez 21 California State Univ. San Bernardino, 2 University of Central Florida.Presentaon Time: 10/4/2010 4:44 PM - 4:46 PMLocaon: Exhibit HallAbstract: We present spectroscopic observaons of several comets with perihelia beyond 5 AU. In recent years many large perihelia comets have beendiscovered with acve dust comae. The gas, which must be driving the dust producon, is rarely detected. These objects are not close enough to the sun forwater sublimaon to be responsible for coma producon, so sublimaon of other volales (CO, CO2) or phase changes in water-ice likely drive the acvity. Theyrepresent a class of comets less altered from their original states than those that regularly pass through the water sublimaon zone and therefore can be used toaddress quesons of cometary composion and disentangle evoluonary effects.We used the LRIS spectrometer (0.3 Å spectral resoluon) on the Keck 10 m telescope atop Mauna Kea, Hawaii in hopes of detecng fluorescence from some ofthe commonly observed visible gas species such as CN, C2 or CO+. Our targets were three Centaurs - 95P/Chiron, 29P/Schwassmann-Wachmann 1 and C/ 2001M10 (NEAT) - and one long-period comet - C/2003 O1 (LINEAR). We present upper limits of gas species producon rates and the gas-to-dust mass loss rao.28.24: Dynamics of Crystalline Silicates in the Coma of Comet 9P/Tempel and the Deep Impact EjectaAuthor Block: Michael S. Kelley 1 , D. H. Wooden 2 , S. S. Lindsay 3 , D. E. Harker 4 , C. E. Woodward 5