M. S. Hanner

University of Massachusetts Amherst, Amherst Center, Massachusetts, United States

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Publications (223)548.15 Total impact

  • M.S. Hanner, M.E. Zolensky
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    ABSTRACT: Cometary dust is a heterogeneous mixture of unequilibrated olivine and pyroxenes, amorphous silicates, Fe-Ni sulfides, and minor amounts of oxides and other minerals. While forsterite Mg2SiO4 and enstatite MgSiO3 are the most common silicate minerals, both the olivine and pyroxenes also show a wide range in Mg/Fe in at least some comets. Carbon in the dust is enriched relative to CI chondrites; a significant fraction of the carbon is in the form of organic refractory material. The return of the particulate sample from ecliptic comet 81P/Wild 2 has opened up a new window for revealing the dust mineralogy at a level of detail not previously possible. The most interesting result from the Wild 2 sample to date is the discovery of refractory calcium aluminum-rich inclusions (CAI) similar to those found in primitive meteorites; chondrule fragments are also present. Comets formed in the outer parts of the solar nebula where temperatures remained low enough so that interstellar grains could have survived. The small glassy silicates in comets may indeed be interstellar grains. The CAI and the widespread, abundant crystalline silicates must have condensed in the hot inner solar nebula; their presence in comets is evidence for strong radial mixing in the solar nebula. The preponderance of Mg-rich silicates has a natural explanation in the condensation sequence; they are the first to condense in a hot gas and only react with iron at lower temperatures. This review discusses the mineralogy of cometary dust determined from infrared spectroscopy, in situ Halley measurements, IDPs, and the captured particles from comet Wild 2.
    09/2010: pages 203-232;
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    ABSTRACT: This data set contains the data from the Galileo dust detector system (GDDS) from start of mission through the end of mission. Included are the dust impact data, noise data, laboratory calibration data, and location and orientation of the spacecraft and instrument.
    NASA Planetary Data System. 06/2010;
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    ABSTRACT: This data set contains the data from the Ulysses dust detector system (UDDS) from start of mission through the end of mission, 1990-2007. (As the dust detector was turned off after Nov. 30, 2007, this is the last date for which UDDS data is recorded.) Included are the dust impact data, noise data, laboratory calibration data, and location and orientation of the spacecraft and instrument.
    NASA Planetary Data System. 06/2010;
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    ABSTRACT: The Ulysses spacecraft has been orbiting the Sun on a highly inclined ellipse (i=79∘, perihelion distance 1.3 AU, aphelion distance 5.4 AU) since it encountered Jupiter in February 1992. Since then it has made almost three revolutions about the Sun. Here we report on the final three years of data taken by the on-board dust detector. During this time, the dust detector recorded 609 dust impacts of particles with masses , bringing the mission total to 6719 dust data sets. The impact rate varied from a low value of 0.3 per day at high ecliptic latitudes to 1.5 per day in the inner solar system. The impact direction of the majority of impacts between 2005 and 2007 is compatible with particles of interstellar origin; the rest are most likely interplanetary particles. We compare the interstellar dust measurements from 2005/2006 with the data obtained during earlier periods (1993/1994) and (1999/2000) when Ulysses was traversing the same spatial region at southern ecliptic latitudes but the solar cycle was at a different phase. During these three intervals the impact rate of interstellar grains varied by more than a factor of two. Furthermore, in the two earlier periods the grain impact direction was in agreement with the flow direction of the interstellar helium while in 2005/2006 we observed a shift in the approach direction of the grains by approximately 30∘ away from the ecliptic plane. The reason for this shift remains unclear but may be connected with the configuration of the interplanetary magnetic field during solar maximum. We also find that the dust measurements are in agreement with the interplanetary flux model of Staubach et al. (1997) which was developed to fit a 5-year span of Ulysses data.
    Planetary and Space Science 08/2009; · 2.11 Impact Factor
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    ABSTRACT: The Galileo spacecraft was orbiting Jupiter between Dec 1995 and Sep 2003. The Galileo dust detector monitored the jovian dust environment between about 2 and 370 R_J (jovian radius R_J = 71492 km). We present data from the Galileo dust instrument for the period January 2000 to September 2003. We report on the data of 5389 particles measured between 2000 and the end of the mission in 2003. The majority of the 21250 particles for which the full set of measured impact parameters (impact time, impact direction, charge rise times, charge amplitudes, etc.) was transmitted to Earth were tiny grains (about 10 nm in radius), most of them originating from Jupiter's innermost Galilean moon Io. Their impact rates frequently exceeded 10 min^-1. Surprisingly large impact rates up to 100 min^-1 occurred in Aug/Sep 2000 when Galileo was at about 280 R_J from Jupiter. This peak in dust emission appears to coincide with strong changes in the release of neutral gas from the Io torus. Strong variability in the Io dust flux was measured on timescales of days to weeks, indicating large variations in the dust release from Io or the Io torus or both on such short timescales. Galileo has detected a large number of bigger micron-sized particles mostly in the region between the Galilean moons. A surprisingly large number of such bigger grains was measured in March 2003 within a 4-day interval when Galileo was outside Jupiter's magnetosphere at approximately 350 R_J jovicentric distance. Two passages of Jupiter's gossamer rings in 2002 and 2003 provided the first actual comparison of in-situ dust data from a planetary ring with the results inferred from inverting optical images. Comment: 59 pages, 13 figures, 6 tables, submitted to Planetary and Space Science
    Planetary and Space Science 08/2009; · 2.11 Impact Factor
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    ABSTRACT: We present 1.20-18.5 μm infrared (IR) spectrophotometric measurements of comet C/1995 O1 (Hale-Bopp) during 1997 February 15 and 20 UT. The spectral energy distribution (SED) was dominated by scattering and thermal emission from submicron sized dust grains that were unusually small. Hale-Bopp's surprising brightness may have been largely a result of the properties of its coma grains rather than the size of its nucleus. The thermal emission continuum from the grains had a superheat of S=Tcolor/TBB ≈ 1.84, the peak of the 10 μm silicate emission feature was 1.81 mag above the carbon grain continuum, and the albedo (reflectivity) of the grains was ≈ 0.41 at a scattering angle of θ ≈ 144°. These are the highest values for these empirical parameters ever observed in 20 years of optical/IR measurements of bright comets. The observations indicate that the optically important grains dominating the visual scattering and near-IR emission from the coma had an average radius of a≤0.4 μm. The strong silicate feature is produced by grains with a similar size range. These dust radii are comparable to the radii of the grains that condense in the outflows of some novae ("stardust") but still about 10 times larger than the average radius of the grains that produce the general interstellar extinction.
    The Astrophysical Journal 01/2009; 489(1):L91. · 6.73 Impact Factor
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    M. S. Hanner, T. Y. Brooke, T. Tokunaga
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    ABSTRACT: We present 8-13 μm spectra of 23 young stars acquired with the UKIRT CGS3 spectrometer, including T Tauri, Herbig Ae/Be, and FU Orionis stars. Silicate emission and absorption features can generally be matched with the Trapezium emissivity, by employing simple models to account for optical depth effects. Two Herbig Ae/Be objects, LkHα 208 and LkHα 198, have emission features that peak at 9.3 μm. These spectra can be adequately fitted with the Trapezium emissivity and a variable optical depth model, plus a hydrocarbon component. A different emissivity peaking at shorter wavelength is not ruled out; however, it is not a necessary conclusion from the observed spectra. Two absorption sources appear to require a narrower emissivity profile. The 11.2 μm peak of crystalline olivine observed in comets is not seen in our YSO spectra, to a limit of 5% for emission sources and 15% for absorption profiles. Aromatic hydrocarbon emission is frequently present in our sample of Herbig Ae/Be stars and is also seen in the T Tauri stars SU Aurigae (G2 III) and DK Tau (K7). Five objects were observed at higher spectral resolution (R ~ 200) to search for spectral structure in the 11 μm region; the aromatic hydrocarbon band at 11.2 μm is resolved into two components at 11.22 and 11.06 μm in LkHα 198 and SU Aur.
    The Astrophysical Journal 01/2009; 502(2):871. · 6.73 Impact Factor
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    ABSTRACT: We present λ = 3-5 and 8-13 μm images and long-slit spectra of comet Hale-Bopp (C/1995 O1) taken in 1997 February-April, near the time of perihelion passage. In agreement with other infrared observations, we find that the 3-13 μm spectral energy distribution was dominated by a 10 μm silicate feature with a strong underlying continuum. In the nuclear region, the feature's peak flux-to-continuum ratio varied from 2.8 on February 17 to 3.3 on April 19, and the color temperature of the 3-5 μm continuum was ~1.8 times the equilibrium blackbody temperature at the relevant heliocentric distance. Both quantities are larger than in any previous comet and indicate a high abundance of submicron dust particles. Spectral structure within the silicate feature reveals the presence of crystalline olivine and pyroxene grains. The physical properties of the grains, as evidenced by their infrared emission, correlated with the morphology. Within the visible jets and halos the silicate feature was up to 15% stronger, and the 8-13 μm color temperature ~1.1 times higher, than in the regions between the halos. Therefore, the halos were enriched in submicron particles relative to the background, as expected from the higher outflow velocities of these small grains. Within the halos, there was no measurable variation in the strength of the silicate feature or the color temperature with distance from the nucleus; that is, we detect no time-dependent evolution of dust particle properties (such as fragmentation) on a timescale of one rotational cycle (between ~2 and 13 hr after ejection). The spectral shape of the silicate feature was essentially the same everywhere in the inner coma in all of our 1997 spectra. Monte Carlo simulation of dust particle motions in the coma indicates that the observed patterns of jets and halos were dominated by submicron-sized grains. Modeling of the thermal emission from small grains demonstrates that the principal features of the 3-13 μm continuum and the 8-13 μm silicate feature can be synthesized from a mixture of amorphous carbon and amorphous and crystalline silicates. The overall shape of the silicate feature resembled that in other bright comets, indicating a similar mineral mix. However, the 10.0 μm peak was sharper in Hale-Bopp near perihelion than in any previously observed comet except comet Mueller (C/1993 A1) at 2 AU.
    The Astrophysical Journal 12/2008; 538(1):428. · 6.73 Impact Factor
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    ABSTRACT: We present infrared images and spectra of comets 2P/Encke, 67P/Churyumov-Gerasimenko, and C/2001 HT50 (LINEAR-NEAT) as part of a larger program to observe comets inside of 5 AU from the Sun with the Spitzer Space Telescope. The nucleus of comet 2P/Encke was observed at two vastly different phase angles (20° and 63°). Model fits to the spectral energy distributions of the nucleus suggest that comet Encke's infrared beaming parameter derived from the near-Earth asteroid thermal model may have a phase angle dependence. The observed emission from comet Encke's dust coma is best modeled using predominately amorphous carbon grains with a grain size distribution that peaks near 0.4 μm, and the silicate contribution by mass to the submicron dust coma is constrained to <31%. Comet 67P/Churyumov-Gerasimenko was observed with distinct coma emission in excess of a model nucleus at a heliocentric distance of 5.0 AU. The coma detection suggests that sublimation processes are still active or grains from recent activity remain near the nucleus. Comet C/2001 HT50 (LINEAR-NEAT) showed evidence for crystalline silicates in the spectrum obtained at 3.2 AU, and we derive a silicate-to-carbon dust ratio of 0.6. The ratio is an order of magnitude lower than that derived for comets 9P/Tempel 1 during the Deep Impact encounter and C/1995 O1 (Hale-Bopp).
    The Astrophysical Journal 12/2008; 651(2):1256. · 6.73 Impact Factor
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    ABSTRACT: We present 1.2-18.3 μm photometry of comet 1995 01 (Hale-Bopp). Our observations spanned nearly 4 months pre- and post-perihelion. The dust grain size-dependent parameters of superheat, 10 μm silicate excess, and albedo are used to make determinations about the Hale-Bopp coma grain population. The evolution of the coma grain size distribution is tracked by measuring these parameters over a range of heliocentric distances. We also observed several regions in the Hale-Bopp coma revealing significant gradients in the measured color temperature suggesting differences in the dust grain size distribution. Finally, we compare the grain size-dependent parameters to those of 11 other bright comets. The extreme values of these parameters displayed by Hale-Bopp suggest it had a smaller mean dust grain size than those associated with the other comets.
    The Astrophysical Journal 12/2008; 549(1):635. · 6.73 Impact Factor
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    ABSTRACT: We present an analysis of the combined infrared data for comet 1P/Halley 1986 III acquired by Gehrz and Ney, Hanner and coworkers, Tokunaga and coworkers, Green and coworkers, Ryan and Campins, and Bregman and coworkers. This database, the largest single body of infrared photometric data for any comet, spans a wavelength range from 0.7 to 23 μm and describes the activity of P/Halley at heliocentric distances from 0.6 to 5.92 AU. Coverage of the thermal infrared spectrum was obtained for heliocentric distances from 0.6 to 2.8 AU. The quantitative corrections and calibration procedures required to intercompare the individual data sets are described. Long-term trends in the heliocentric dependence of P/Halley's grain color temperature, silicate emission optical strength, average grain albedo, apparent luminosity, and infrared monochromatic fluxes are discussed. The normalized thermal infrared flux varied as r-2.2 preperihelion and r-2.1 postperihelion in accord with the slope of the water production rate, indicating a general correlation between dust and gas production. Large-amplitude short-term (hours) fluctuations in all the observable quantities were seen in small apertures; these changes correlated with gas production rates and the presence of jets. Changes in JHK colors and the incomplete correlation between superheat and silicate feature strength imply variability in the grain composition, as well as in the size distribution. Based on a comparison of infrared data, comet Hale-Bopp (C/1995 O1) ejected a much higher relative abundance of submicron grains than Halley, and this pattern persisted to larger heliocentric distances.
    The Astronomical Journal 12/2007; 130(5):2383. · 4.97 Impact Factor
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    ABSTRACT: We present the first results of the Palomar Adaptive Optics observations taken during the Deep Impact encounter with 9P/Tempel 1 in July 2005. We have combined the Palomar near-IR imaging data with our visual wavelength images obtained simultaneously at JPL's Table Mountain Observatory to cover the total wavelength range from 0.4 to 2.3 μm in the B, V, R, I, J, H, and K filter bands, spanning the dates from 2005 July 03–07. We also include in our overall analysis images taken on the pre-encounter dates of June 1 and June 15, 2005. The broad wavelength range of our observations, along with high temporal resolution, near-IR sensitivity, and spatial resolution of our imaging, have enabled us to place constraints on the temperature of the impact flash and incandescent plume of >700 K, and to provide mean dust velocities of order approximately 1.25 h after impact derived from our 1.64 μm observations. Our ejected dust mass estimates, as derived from our near-IR observations, are an order of magnitude less than those previously reported for visual wavelength observations.
    Icarus 01/2007; · 3.16 Impact Factor
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    ABSTRACT: An outstanding question in modern astrophysics is understanding conditions extant in early protoplanetary disks during the epoch of planetesimal formation. In our own solar system, comets are frozen archives of this early epoch. Here we present preliminary results from our optical ground-based support and the Spitzer CY2 infrared observations of selected comets, both Jupiter-family and Oort Cloud members. The science driver of our CY2 program is the spectroscopic study of comets. However, interlacing multiple-order high resolution IR spectroscopy data to confirm the detection of narrow crystalline features requires properly correcting for slit losses. Proper determination of correction factors requires both contemporaneous infrared imaging and optical ground-based support observations to assess coma surface brightness. For select comets in our study, we used the Spitzer IRAC camera to obtain images at 4.5 and 7.9 microns and MIPS 24 (Multiband Imaging Photometer) for photometric information at 24 microns. These instruments can detect cometary nuclei and image coma to larger cometocentric distances and lower surface brightness flux densities. In addition, these images can also be used to investigate how coma activity and grain properties may be correlated with jets. A main goal of our ground-based support initiative was to obtain precise photometry at 0.7 microns, and from images determine the morphology of comet nuclei and near-nucleus structures (e.g. jets, structures in the coma surface brightness). The ground-based observations also enable mapping cometary activity over many rotation periods of the nuclei and to observe and assess how morphological changes evolve. Also our ground-based program provided data to improve orbital elements for Spitzer CY2 targets, especially recover a "lost" comet 71P/Clark, which we successfully observed on 2005 Dec 22 UT with the UH 2.2-m telescope, and the derivation of new orbital positions for two nuclei of comet C/2005 A1 Linear which split on 2005 July 05. Support for this work was provided by JPL/NASA contract #1278383.
    08/2006;
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    ABSTRACT: The Ulysses spacecraft has been orbiting the Sun on a highly inclined ellipse (i = 79 degrees, perihelion distance 1.3 AU, aphelion distance 5.4 AU) since it encountered Jupiter in 1992. Between January 2000 and December 2004, the spacecraft completed almost an entire revolution about the Sun, passing through perihelion in May 2001 and aphelion in July 2004. In this five-year period the dust detector on board recorded 4415 dust impacts. We publish and analyse the complete data set of both raw and reduced data for particles with masses 10(-16) g <= M <= 10(-7) g. Together with. 1695 dust impacts recorded between launch of Ulysses and the end of 1999 published earlier (Grain, E., Baguhl, M., Divine, N., Fechtig, H., Hamilton, D.P, Harmer, M.S., Kissel, J., Lindblad, B.A., Linkert, D., Linkert, G., Mann, L, McDonnell, J.A.M., Morfill, G.E., Polanskey, C., Riemann, R., Schwehm, G.H., Siddique, N., Staubach, P., Zook, H.A., 1995a. Two years of Ulysses dust data. Planetary Space Sci. 43, 971-999, Paper III; Kruger, H., Grun, E., Landgraf, M., Baguhl, M., Dermott, S.F., Fechtig, H., Gustafson, B.A., Hamilton, D.P., Harmer, M.S., Horanyi, M., Kissel, J., Lindblad, B., Linkert, D., Linkert, G., Mann, L, McDonnell, J.A.M., Morfill, G.E., Polanskey, C., Schwehm, G.H., Srama, R., Zook, H.A., 1995. Three years of Ulysses dust data: 1993 to 1995. Planetary and Space Sci. 47, 363-383, Paper V; Kruger, H., Grun, E., Landgraf, M., Dermott, S.F., Fechtig, H., Gustafson, B.A., Hamilton, D.P., Harmer, M.S., Horanyi, M., Kissel, J., Lindblad, B., Linkert, D., Linkert, G., Mann, I., McDonnell, J.A.M., Morfill, G.E., Polanskey, C., Schwehm, G.H., Srama, R., Zook, H.A., 2001b. Four years of Ulysses dust data: 1996 to 1999. Planetary Space Sci. 49, 1303-1324, Paper VII), a data set of 6110 dust impacts detected with the Ulysses sensor between October 1990 and December 2004 is now available. The impact rate measured between 2000 and 2002 was relatively constant with about 0.3 impacts per day showing a maximum at 1.5 per day around ecliptic plane crossing in early-2001. The impact direction of the majority of impacts between 2000 and 2002 is compatible with particles of interstellar origin, the rest are most likely interplanetary particles. In 2003 and 2004 dust stream particles originating from the jovian system dominated the overall impact rate. Twenty-two individual dust streams were measured between November 2002 and December 2004. The observed impact rates are compared with models for interplanetary and interstellar dust. The dust measurements from the entire mission since Ulysses launch give good agreement with the interplanetary flux model of Staubach, P., Grun, E., Jehn, R., 1997. The meteoroid environment near Earth, Adv. Space Res. 19, 301-308.
    Planetary and Space Science 08/2006; · 2.11 Impact Factor
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    ABSTRACT: The dust detector system on board the Galileo spacecraft recorded dust impacts in circumjovian space during the craft's orbital mission about Jupiter. This is the eighth in a series of papers dedicated to presenting Galileo and Ulysses dust data. We present data from the Galileo dust instrument for the period January 1997–December 1999 when the spacecraft completed 21 revolutions about Jupiter. In this time interval data were obtained as high resolution realtime science data or recorded data during 449 days (representing 41% of the entire period), or via memory readouts during the remaining times. Because the data transmission rate of the spacecraft was very low, the complete data set (i.e. all parameters measured by the instrument during impact of a dust particle) of only 3% (7625) of all particles detected could be transmitted to Earth; the other particles were only counted. Together with the data of 2883 particles detected during Galileo's interplanetary cruise and 5353 particles detected in the jovian system in 1996, complete data of 15 861 particles detected by the Galileo dust instrument from 1989 to 1999 are now available. The majority of the detected particles were tiny grains (about 10 nm in radius), most of them originating from Jupiter's innermost Galilean moon Io. They were detected throughout the jovian system and the highest impact rates exceeded (C21 orbit; 01 July 1999). With the new data set the times of onset, cessation and a 180∘ shift in the impact direction of the grains measured during 19 Galileo orbits about Jupiter are well reproduced by simulated 9 nm particles charged up to a potential of , confirming earlier results obtained for only two Galileo orbits (Horányi, M., Grün, E., Heck, A., 1997. Modeling the Galileo dust measurements at Jupiter. Geophys. Res. Lett. 24, 2175–2178). Galileo has detected a large number of bigger particles mostly in the region between the Galilean moons. The average radius of 370 of these grains measured in the 1996–1999 period is about (assuming spherical grains with density ) and the size distribution rises steeply towards smaller grains. The biggest detected particles have a radius of about .
    Planetary and Space Science 01/2006; · 2.11 Impact Factor
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    ABSTRACT: A key scientific challenge in modern astrophysics is to understand conditions in early protoplanetary disks during the epoch of planetesimal formation. In our own solar system, comets are frozen archives of this early epoch. We propose to study 14 sublimating comets (both Jupiter-family and Oort Cloud members) in a 55.0 hr (42 AORs) program to characterize the coma and nuclear spectra and to establish a statistically sample of high quality cometary spectra. We seek to: 1) study their dust characteristics; 2) search for possible organic (PAH-like) signatures; and 3) address a fundamental question -- the origins of crystalline silicates in the solar nebula. A major objective of our program is a comprehensive survey of faint Jupiter-family comet dust properties, which will permit an in-depth, systematic comparison of Jupiter-family and Oort Cloud comet dust properties and physical characteristics, facilitate assessment of the importance of crystalline silicates as a diagnostic of solar nebula evolution and turbulent mixing models, and establish critical remote-sensing data products to provide interpretive context for NASA and ESA comet rendezvous and sample return missions. Only Spitzer has the sensitivity at mid- and far-IR wavelengths to detect the significant diagnostic spectral features/resonances emitted by dust and organics necessary to effect this study.
    Spitzer Proposal. 06/2005;
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    ABSTRACT: Until the commissioning of the Spitzer Space Telescope our knowledge of the mid-infrared properties of comets was limited to the brightest comets as seen by observers on Earth. With Spitzer, we have the sensitivity to obtain mid-IR spectra of the average comet at a variety of heliocentric distances (>1.5 AU) that enable investigation of their physical characteristics and dust properties. We have nearly completed our initial survey program to investigate comets with favorable Spitzer targeting windows during the first year of the observatory's operation. Successful observations include both low and high resolution spectra with associated peak up images. The program mostly consists of Jupiter-family comets but also includes a few Halley-family, long period, and dynamically new comets. We have spectra of the Stardust and Rosetta mission targets (81P/Wild 2 and 67P/Churyumov-Gerasimenko), spectra of silicate emission in a Jupiter-family comet (62P/Tsuchinshan 1), and the potential detection of crystalline olivine features at 23.5 and 23.5 μ m in a dynamically new comet (C/2001 Q4 (NEAT)). We present preliminary results on the dust production and nuclear sizes of our program comets. This work is supported in part by NASA/JPL contract 1263741 to the University of Minnesota.
    04/2005; 37:485.
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    ABSTRACT: HD 45677, HD 50138, two B type stars, HD 31468 and HD 163296, two A type stars with circumstellar disks, have displayed variability in their data over a period of a few years. Using computer modeling codes, spectral energy distribution fits of the 0.1-100 micron region for these objects at different times are presented. Rough estimates of density and material component distribution of the circumstellar dust are obtained. It is hoped that the comparison of these time dependent fits can help to determine how the circumstellar dust is evolving in size and shape and how this is causing the variability in the data of these two objects. This work has been supported by NASA's Origins of Solar Systems Program, the University Research Council of the University of Cincinnati, and the Aerospace Corporation's Independent Research and Development Program.
    12/2004;
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    ABSTRACT: With the advent of new laboratory analytical tools and in situ detectors in space, the analysis of solids in space is on the verge of becoming a true, experimentally-based science. Here we outline a broad strategy for studying the mineralogical nature of solids in dusty protostellar disks.
    11/2004; 324:221.
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    ABSTRACT: A key scientific challenge in modern astrophysics is to understand conditions in early protoplanetary disks during the epoch of planetesimal formation. In our own solar system, comets are frozen archives of this early epoch. Using Spitzer (+IRS), we propose an extensive 45.9 hr study of 52 select comets (both Jupiter- and Oort-family members). We will investigate their physical properties and dust characteristics, and search for possible organic (PAH-like) signatures, creating the first comprehensive mid- and far-infrared database of these relic, nearly pristine samples of outer solar nebula materials. Our program will enable the first comprehensive survey of faint Jupiter-family comet dust properties, permit an in-depth, systematic comparison of Jupiter- and Oort-family comet dust properties and physical characteristics, facilitate assessment of the importance of crystalline silicates as a diagnostic of solar nebula evolution and turbulent mixing models, and establish critical remote-sensing data products to provide interpretive context for NASA and ESA comet rendezvous and sample return missions. Only Spitzer has the mJy sensitivity at mid- and far-infrared wavelengths to detect the significant diagnostic spectral features/resonances emitted by dust, organics, and ices, necessary to effect this survey program.
    Spitzer Proposal. 09/2004;

Publication Stats

3k Citations
548.15 Total Impact Points

Institutions

  • 2004–2010
    • University of Massachusetts Amherst
      • Department of Astronomy
      Amherst Center, Massachusetts, United States
  • 1981–2009
    • California Institute of Technology
      • Jet Propulsion Laboratory
      Pasadena, California, United States
  • 1997
    • Observatoire de Paris
      Lutetia Parisorum, Île-de-France, France
    • University of Wyoming
      Laramie, Wyoming, United States
    • Max Planck Institute for Nuclear Physics
      Heidelburg, Baden-Württemberg, Germany
    • Cornell University
      • Center for Radiophysics and Space Research (CRSR)
      Ithaca, NY, United States
  • 1974–1978
    • Max Planck Institute for Astronomy
      Heidelburg, Baden-Württemberg, Germany