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Mainzer A.,Jet Propulsion Laboratory | Grav T.,Johns Hopkins University | Masiero J.,Jet Propulsion Laboratory | Bauer J.,Jet Propulsion Laboratory | And 5 more authors.
Astrophysical Journal Letters | Year: 2011

With thermal infrared observations detected by the NEOWISE project, we have measured diameters for 1742 minor planets that were also observed by the Infrared Astronomical Satellite (IRAS). We have compared the diameters and albedo derived by applying a spherical thermal model to the objects detected by NEOWISE and find that they are generally in good agreement with the IRAS values. We have shown that diameters computed from NEOWISE data are often less systematically biased than those found with IRAS. This demonstrates that the NEOWISE data set can provide accurate physical parameters for the >157,000 minor planets that were detected by NEOWISE. © 2011. The American Astronomical Society. All rights reserved.


Masiero J.R.,Jet Propulsion Laboratory | Mainzer A.K.,Jet Propulsion Laboratory | Grav T.,Johns Hopkins University | Bauer J.M.,Jet Propulsion Laboratory | And 18 more authors.
Astrophysical Journal | Year: 2011

We present initial results from the Wide-field Infrared Survey Explorer (WISE), a four-band all-sky thermal infrared survey that produces data well suited for measuring the physical properties of asteroids, and the NEOWISE enhancement to the WISE mission allowing for detailed study of solar system objects. Using a NEATM thermal model fitting routine, we compute diameters for over 100,000 Main Belt asteroids from their IR thermal flux, with errors better than 10%. We then incorporate literature values of visible measurements (in the form of the H absolute magnitude) to determine albedos. Using these data we investigate the albedo and diameter distributions of the Main Belt. As observed previously, we find a change in the average albedo when comparing the inner, middle, and outer portions of the Main Belt. We also confirm that the albedo distribution of each region is strongly bimodal. We observe groupings of objects with similar albedos in regions of the Main Belt associated with dynamical breakup families. Asteroid families typically show a characteristic albedo for all members, but there are notable exceptions to this. This paper is the first look at the Main Belt asteroids in the WISE data, and only represents the preliminary, observed raw size, and albedo distributions for the populations considered. These distributions are subject to survey biases inherent to the NEOWISE data set and cannot yet be interpreted as describing the true populations; the debiased size and albedo distributions will be the subject of the next paper in this series. © 2011. The American Astronomical Society. All rights reserved.


Debes J.H.,NASA | Hoard D.W.,California Institute of Technology | Kilic M.,Smithsonian Astrophysical Observatory | Wachter S.,California Institute of Technology | And 4 more authors.
Astrophysical Journal | Year: 2011

With the launch of the Wide-Field Infrared Survey Explorer (WISE), a new era of detecting planetary debris around white dwarfs (WDs) has begun with the WISE InfraRed Excesses around Degenerates (WIRED) Survey. The WIRED survey will be sensitive to substellar objects and dusty debris around WDs out to distances exceeding 100pc, well beyond the completeness level of local WDs and covering a large fraction of known WDs detected with the SDSS DR4 WD catalog. In this paper, we report an initial result of the WIRED survey, the detection of the heavily polluted hydrogen WD (spectral type DAZ) GALEX J193156.8+011745 at 3.35 and 4.6 μm. We find that the excess is consistent with either a narrow dusty ring with an inner radius of 29 R WD, outer radius of 40 R WD, and a face-on inclination, or a disk with an inclination of 70°, an inner radius of 23 R WD, and an outer radius of 80 R WD. We also report initial optical spectroscopic monitoring of several metal lines present in the photosphere and find no variability in the line strengths or radial velocities of the lines. We rule out all but planetary mass companions to GALEX1931 out to 0.5 AU. © 2011. The American Astronomical Society. All rights reserved.


Mainzer A.,Jet Propulsion Laboratory | Grav T.,Planetary Science Institute | Masiero J.,Jet Propulsion Laboratory | Bauer J.,Jet Propulsion Laboratory | And 7 more authors.
Astrophysical Journal Letters | Year: 2012

Enhancements to the science data processing pipeline of NASA's Wide-field Infrared Survey Explorer (WISE) mission, collectively known as NEOWISE, resulted in the detection of >158,000 minor planets in four infrared wavelengths during the fully cryogenic portion of the mission. Following the depletion of its cryogen, NASA's Planetary Science Directorate funded a four-month extension to complete the survey of the inner edge of the Main Asteroid Belt and to detect and discover near-Earth objects (NEOs). This extended survey phase, known as the NEOWISE Post-Cryogenic Survey, resulted in the detection of 6500 large Main Belt asteroids and 86 NEOs in its 3.4 and 4.6 μm channels. During the Post-Cryogenic Survey, NEOWISE discovered and detected a number of asteroids co-orbital with the Earth and Mars, including the first known Earth Trojan. We present preliminary thermal fits for these and other NEOs detected during the 3-Band Cryogenic and Post-Cryogenic Surveys. © 2012. The American Astronomical Society. All rights reserved..


Mainzer A.,Jet Propulsion Laboratory | Masiero J.,Jet Propulsion Laboratory | Grav T.,Johns Hopkins University | Bauer J.,Jet Propulsion Laboratory | And 11 more authors.
Astrophysical Journal | Year: 2012

We have combined the NEOWISE and Sloan Digital Sky Survey data to study the albedos of 24,353 asteroids with candidate taxonomic classifications derived using Sloan photometry. We find a wide range of moderate to high albedos for candidate S-type asteroids that are analogous to the S complex defined by previous spectrophotometrically based taxonomic systems. The candidate C-type asteroids, while generally very dark, have a tail of higher albedos that overlaps the S types. The albedo distribution for asteroids with a photometrically derived Q classification is extremely similar to those of the S types. Asteroids with similar colors to (4) Vesta have higher albedos than the S types, and most have orbital elements similar to known Vesta family members. Finally, we show that the relative reflectance at 3.4 and 4.6 μm is higher for D-type asteroids and suggest that their red visible and near-infrared spectral slope extends out to these wavelengths. Understanding the relationship between size, albedo, and taxonomic classification is complicated by the fact that the objects with classifications were selected from the visible/near-infrared Sloan Moving Object Catalog, which is biased against fainter asteroids, including those with lower albedos. © 2012. The American Astronomical Society. All rights reserved.


Mainzer A.,Jet Propulsion Laboratory | Grav T.,Planetary Science Institute | Masiero J.,Jet Propulsion Laboratory | Bauer J.,Jet Propulsion Laboratory | And 10 more authors.
Astrophysical Journal | Year: 2012

We present the preliminary results of an analysis of the sub-populations within the near-Earth asteroids, including the Atens, Apollos, Amors, and those that are considered potentially hazardous using data from the Wide-field Infrared Survey Explorer (WISE). In order to extrapolate the sample of objects detected by WISE to the greater population, we determined the survey biases for asteroids detected by the project's automated moving object processing system (known as NEOWISE) as a function of diameter, visible albedo, and orbital elements. Using this technique, we are able to place constraints on the number of potentially hazardous asteroids larger than 100 m and find that there are ̃4700 ± 1450 such objects. As expected, the Atens, Apollos, and Amors are revealed by WISE to have somewhat different albedo distributions, with the Atens being brighter than the Amors. The cumulative size distributions of the various near-Earth object (NEO) subgroups vary slightly between 100 m and 1km. A comparison of the observed orbital elements of the various sub-populations of the NEOs with the current best model is shown. © 2012. The American Astronomical Society. All rights reserved..


Ressler M.E.,Jet Propulsion Laboratory | Cohen M.,Monterey Institute for Research in Astronomy | Wachter S.,California Institute of Technology | Hoard D.W.,California Institute of Technology | And 2 more authors.
Astronomical Journal | Year: 2010

We report the discovery of a pair of infrared, axisymmetric rings in the planetary nebula NGC 1514 during the course of theWISE all-sky mid-infrared survey. Similar structures are seen at visible wavelengths in objects such as the "Engraved Hourglass Nebula" (MyCn 18) and the "Southern Crab Nebula" (Hen 2-104). However, in NGC 1514 we see only a single pair of rings and they are easily observed only in the mid-infrared. These rings are roughly 0.2 pc in diameter, are separated by 0.05 pc, and are dominated by dust emission with a characteristic temperature of 160 K.We compare the morphology and color of the rings to the other nebular structures seen at visible, far-infrared, and radio wavelengths, and close with a discussion of a physical model and formation scenario for NGC 1514. © 2010. The American Astronomical Society. All rights reserved.


Debes J.H.,NASA | Debes J.H.,US Space Telescope Science Institute | Hoard D.W.,California Institute of Technology | Wachter S.,California Institute of Technology | And 2 more authors.
Astrophysical Journal, Supplement Series | Year: 2011

With the launch of the Wide-field Infrared Survey Explorer (WISE), a new era of detecting planetary debris and brown dwarfs (BDs) around white dwarfs (WDs) has begun with the WISE InfraRed Excesses around Degenerates (WIRED) Survey. The WIRED Survey is sensitive to substellar objects and dusty debris around WDs out to distances exceeding 100pc, well beyond the completeness level of local WDs. In this paper, we present a cross-correlation of the preliminary Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) WD catalog between the WISE, Two-Micron All Sky Survey (2MASS), UKIRT Infrared Deep Sky Survey (UKIDSS), and SDSSDR7 photometric catalogs. From 18,000 input targets, there are WISE detections comprising 344 "naked" WDs (detection of the WD photosphere only), 1020 candidate WD+M dwarf binaries, 42 candidate WD+BD systems, 52 candidate WD+dust disk systems, and 69 targets with indeterminate infrared excess. We classified all of the detected targets through spectral energy distribution model fitting of the merged optical, near-IR, and WISE photometry. Some of these detections could be the result of contaminating sources within the large (6″) WISE point-spread function; we make a preliminary estimate for the rates of contamination for our WD+BD and WD+disk candidates and provide notes for each target of interest. Each candidate presented here should be confirmed with higher angular resolution infrared imaging or infrared spectroscopy. We also present an overview of the observational characteristics of the detected WDs in the WISE photometric bands, including the relative frequencies of candidate WD+M, WD+BD, and WD+disk systems. © 2011. The American Astronomical Society. All rights reserved.


Debes J.H.,US Space Telescope Science Institute | Hoard D.W.,California Institute of Technology | Farihi J.,University of Leicester | Wachter S.,California Institute of Technology | And 2 more authors.
Astrophysical Journal | Year: 2012

We present the discovery with WISE of a significant infrared excess associated with the eclipsing post-common envelope binary SDSS J030308.35+005443.7, the first excess discovered around a non-interacting white dwarf+main-sequence M dwarf binary. The spectral energy distribution of the white dwarf+M dwarf companion shows significant excess longward of 3μm. A T eff of 8940K for the white dwarf is consistent with a cooling age >2Gyr, implying that the excess may be due to a recently formed circumbinary dust disk of material that extends from the tidal truncation radius of the binary at 1.96 R ⊙ out to <0.8 AU, with a total mass of 1020 g. We also construct WISE and follow-up ground-based near-infrared light curves of the system and find variability in the K band that appears to be in phase with ellipsoidal variations observed in the visible. The presence of dust might be due to (1) material being generated by the destruction of small rocky bodies that are being perturbed by an unseen planetary system or (2) dust condensing from the companion's wind. The high inclination of this system and the presence of dust make it an attractive target for M dwarf transit surveys and long-term photometric monitoring. © 2012. The American Astronomical Society. All rights reserved..


Hoard D.W.,Max Planck Institute for Astronomy | Hoard D.W.,Eureka Scientific Inc. | Debes J.H.,US Space Telescope Science Institute | Wachter S.,Max Planck Institute for Astronomy | And 2 more authors.
Astrophysical Journal | Year: 2013

We have compiled photometric data from the Wide-field Infrared Survey Explorer All Sky Survey and other archival sources for the more than 2200 objects in the original McCook & Sion Catalog of Spectroscopically Identified White Dwarfs. We applied color-selection criteria to identify 28 targets whose infrared spectral energy distributions depart from the expectation for the white dwarf (WD) photosphere alone. Seven of these are previously known WDs with circumstellar dust disks, five are known central stars of planetary nebulae, and six were excluded for being known binaries or having possible contamination of their infrared photometry. We fit WD models to the spectral energy distributions of the remaining ten targets, and find seven new candidates with infrared excess suggesting the presence of a circumstellar dust disk. We compare the model dust disk properties for these new candidates with a comprehensive compilation of previously published parameters for known WDs with dust disks. It is possible that the current census of WDs with dust disks that produce an excess detectable at K-band and shorter wavelengths is close to complete for the entire sample of known WDs to the detection limits of existing near-IR all-sky surveys. The WD dust disk candidates now being found using longer wavelength infrared data are drawn from a previously underrepresented region of parameter space, in which the dust disks are overall cooler, narrower in radial extent, and/or contain fewer emitting grains. © 2013. The American Astronomical Society. All rights reserved.

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