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The 3-13 μm spectra of Deimos and Phobos were obtained on the nights of 2003 August 19, 20, and 21 UT, within a week of opposition (August 28). Spectra in the 1.5-2.5 μm region were taken a few weeks earlier on July 26. Observations were made near greatest elongation for each satellite in order to minimize scattered light from Mars. The L, M, and narrowband N (10.2 μm) magnitudes for Deimos were 7.7 ± 0.1, 4.9 ± 0.1, and 0.79 ± 0.09, respectively. The L, M, and narrowband N (10.2 μm) magnitudes for Phobos were 6.4, 3.8, and -0.52, respectively, all ±0.07. The 5-12 μm color temperatures of Deimos and Phobos were 344 ± 5 and 357 ± 5 K, respectively, significantly higher than the blackbody thermal equilibrium temperature for either a fast rotator at Mars's heliocentric distance (237 K) or a slow rotator (282 K). The high brightness temperatures of Deimos and Phobos in the thermal infrared of 310-330 and 320-340 K, respectively, are not understood, but they are somewhat consistent with the high color temperatures. Within the errors, there was little evidence for spectral features indicative of surface composition, although there were some 1-2 σ variations that warrant further observations.

We present the first published spatially resolved images of Neptune's thermal emission. Our 7.7 and 11.7 μm images, taken on 2005 July 4 and 5 at the Gemini North telescope, show enhanced methane and ethane emission within 30° of the south pole. This bright polar region is the first direct imaging evidence for radiative forcing of Neptune's stratosphere, similar to that seen on Saturn. Enhanced emission from ethane, but not methane, also emerges from the planetary limb, suggesting differing vertical profiles. Stratospheric emissions are uncorrelated with tropospheric clouds seen in reflected sunlight in our near-simultaneous adaptive optics images at 1.6 and 2.2 μm taken with the Keck II telescope on 2005 July 5.

FU Orionis stars are a small group of pre–main-sequence stars known for large-amplitude optical variability. These objects also exhibit multiwavelength phenomena suggestive of active accretion from a circumstellar disk. We present high spatial resolution mid-IR imaging and spectroscopy, submillimeter photometry, and 3–4 μm photometry of four FU Ori–class objects, RNO 1B and C, Z CMa, and Par 21, and one object classified as a pre–FU Ori star, V380 Ori. We resolve multiple IR sources and extended emission in the RNO 1B/C system, and we discuss in detail their association with disk activity and the source of the Infrared Astronomical Satellite far-IR and radio maser emission in this field. We derive dust temperatures and masses for all sources and discuss how dust composition and morphology is related to the evolutionary stage of these objects.

Contemporaneous near-infrared (0.8–2.5 μm) and infrared (3–14 μm) spectroscopy is presented of the previously uncharacterized IRAS source 07077+1536. The data show it to be a carbon star embedded in a circumstellar dust envelope. The near-infrared spectrum displays molecular absorption features of C2, CN, and CO, while the 11 μm emission feature from SiC is present in the thermal infrared. The spectral energy distribution of IRAS 07077+1536 is similar to the so-called extreme carbon stars in that it consists primarily of a reddened stellar photosphere and thermal dust emission. However, the extinction is much less and the dust significantly warmer (~900 K vs. ~300 K) than in extreme carbon stars such as AFGL 3068. IRAS 07077+1536 is also unusually bright shortward of 0.5 μm, an aspect that could be due to variability but may indicate the presence of a binary companion or a foreground star.

We report 3–14 μm spectroscopy of the nova V445 Puppis on 2001 January 31.45 UT using the Broadband Array Spectrograph System on the Infrared Telescope Facility, approximately 1 month after the object was discovered. The spectrum (W cm-2 μm-1) revealed only a smooth, featureless continuum that decreases monotonically with increasing wavelengths between 3 and 13.6 μm. Its slope is much shallower than the Rayleigh-Jeans tail of a blackbody. The spectrum is consistent with thermal emission from gray (constant) emissivity dust whose temperatures ranged from around 280 K to upward of 1300 K. IR magnitudes were L = 2.8, M = 1.6, and N = -0.27, all ±0.02. The presence of such strong IR continuum emission so early after the nova's outburst may suggest that this object has undergone previous outbursts and that we observed preexisting dust, at least in part

We present mid-infrared spectra and images from the GEMINI-N (+Michelle) observations of fragments SW3-[B] and SW3-[C] of the ecliptic (Jupiter Family) comet 73P/Schwassmann-Wachmann 3 pre-perihelion. We observed fragment B soon after an outburst event (between 2006 April 16–26 UT) and detected crystalline silicates. The mineralogy of both fragments was dominated by amorphous carbon and amorphous pyroxene. The grain size distribution (assuming a Hanner modified power-law) for fragment SW3-[B] has a peak grain radius of μm, and for fragment SW3-[C], μm; both values are larger than the peak grain radius of the size distribution for the dust ejected from ecliptic comet 9P/Tempel 1 during the Deep Impact event ( μm). The silicate-to-carbon ratio and the silicate crystalline mass fraction for the submicron to micron-size portion of the grain size distribution on the nucleus of fragment SW3-[B] were and , respectively, while on the nucleus of fragment SW3-[C], they were and , respectively. The similarity in mineralogy and grain properties between the two fragments implies that 73P/Schwassmann-Wachmann 3 is homogeneous in composition. The slight differences in grain size distribution and silicate-to-carbon ratio between the two fragments likely arise because SW3-[B] was actively fragmenting throughout its passage, while the activity in SW3-[C] was primarily driven by jets. The lack of diverse mineralogy in the fragments SW3-[B] and SW3-[C] of 73P/Schwassmann-Wachmann 3 along with the relatively larger peak in the coma grain size distribution suggests the parent body of this comet may have formed in a region of the solar nebula with different environmental properties than the natal sites where comet C/1995 O1 (Hale-Bopp) and 9P/Tempel 1 nuclei aggregated.

We report here on a series of medium resolution spectro-photometric observations of the enigmatic long period eclipsing binary epsilon Aurigae, during its eclipse interval of 2009-2011, using near-infrared spectra obtained with SpeX on the Infrared Telescope Facility (IRTF), mid-infrared spectra obtained with BASS on AOES and IRTF, MIRSI on IRTF, and MIRAC4 on the MMT, along with mid-infrared photometry using MIRSI on IRTF and MIRAC4 on the MMT, plus 1995-2000 timeframe published photometry and data obtained with Denver's TNTCAM2 at WIRO. The goals of these observations included: (1) comparing eclipse depths with prior eclipse data, (2) confirming the re-appearance of CO absorption bands at and after mid-eclipse, associated with sublimation in the disk, (3) seeking evidence for any mid-infrared solid state spectral features from particles in the disk, and (4) providing evidence that the externally irradiated disk has azimuthal temperature differences. IR eclipse depths appear similar to those observed during the most recent (1983) eclipse, although evidence for post-mid-eclipse disk temperature increase is present, due to F star heated portions of the disk coming into view. Molecular CO absorption returned 57 days after nominal mid-eclipse, but was not detected at mid-eclipse plus 34 days, narrowing the association with differentially heated sub-regions in the disk. Transient He I 10830A absorption was detected at mid-eclipse, persisting for at least 90 days thereafter, providing a diagnostic for the hot central region. The lack of solid-state features in Spitzer Infrared Spectrograph, BASS, and MIRAC spectra to date suggests the dominance of large particles (micron-sized) in the disk. Based on these observations, mid-infrared studies out of eclipse can directly monitor and map the disk thermal changes, and better constrain disk opacity and thermal conductivity.

We have used the Spitzer Space Telescope Infrared Spectrograph (IRS) to observe the 5-37 micron thermal emission of comet 73P/Schwassmann-Wachmann 3 (SW3), components B and C. We obtained low spectral resolution (R ~ 100) data over the entire wavelength interval, along with images at 16 and 22 micron. These observations provided an unprecedented opportunity to study nearly pristine material from the surface and what was until recently the interior of an ecliptic comet - cometary surface having experienced only two prior perihelion passages, and including material that was totally fresh. The spectra were modeled using a variety of mineral types including both amorphous and crystalline components. We find that the degree of silicate crystallinity, ~ 35%, is somewhat lower than most other comets with strong emission features, while its abundance of amorphous carbon is higher. Both suggest that SW3 is among the most chemically primitive solar system objects yet studied in detail, and that it formed earlier or farther from the sun than the bulk of the comets studied so far. The similar dust compositions of the two fragments suggests that these are not mineralogically heterogeneous, but rather uniform throughout their volumes. Atomic abundances derived from the spectral models indicates a depletion of O compared to solar photospheric values, despite the inclusion of water ice and gas in the models. Atomic C may be solar or slightly sub-solar, but its abundance is complicated by the potential contribution of spectrally featureless mineral species to the portion of the spectra most sensitive to the derication of the C abundance. We find a relatively high bolometric albedo, ~ 0.13 for the dust, considering the large amount of dark carbonaceous material, but consistent with the presence of abundant small particles and strong emission features., Comment: 70 pages, 21 figures, accepted for publication in AJ

Further data on the polarization of the far-infrared (wavelength greater than 40 microns) emission from the Orion Nebula shows no evidence for polarized emission by aligned grains. Results at wavelength about 71-115 microns are consistent with a small (about 1.5%) absorption-induced polarization with about the same position angle on the sky as the polarization measured at shorter wavelengths.