ALBERT

Description: IRAS data have been used to examine the vicinity of nearly 100 dense clumps of molecular gas observed in lines of CO and NH3. More than one-third of these molecular cloud 'cores' contain infrared sources that appear to be newly formed, or forming, low mass stars. While about one-third of the infrared sources are associated with visible stars and have properties that resemble T Tauri stars, the remainder of the infrared sources have no optical counterparts and are probably embedded within the molecular cloud itself. These invisible sources lie close to the molecular cloud peaks and have cold, massive shells of material around them. Some of the cores without infrared sources have gas properties similar to those with embedded sources and so may be on the verge of gravitational collapse. The selection of the IRAS sample and its properties are described. The spectral energy distributions of the sources and their nature are discussed along with their physical properties, the properties of cores with and without infrared sources, and the time scale for the evolution of the sources.

Description: Integrated and individual-star observations of 47 Tuc obtained at 12, 25, 60, and 100 microns by IRAS are reported. The data are presented in tables and brightness contour maps and analyzed. Features discussed include integrated light dominated by stellar photospheric emission, 12- and 25-micron excesses (associated with red giants in the outer region of the cluster), and a small excess at 100 microns (attributed to integrated-light heating of about 0.0003 solar mass of silicate dust within 6 arcmin of the cluster center). It is pointed out that this is much less dust than predicted by theoretical models of accumulation since the cluster passed through the Galactic plane about 30 Myr ago, and possible dust-removal mechanisms are considered.

Description: The Infrared Astronomical Satellite (IRAS) Point Source catalog was searched for sources brighter than 28 Jy (0 mag) at 12 microns with absolute galactic latitude greater than 30 deg excluding the Large Magellanic Cloud. The search resulted in 269 sources, two of which are the galaxies NGC 1068 and M82. The remaining 267 sources are identified with, or have infrared color indices consistent with late-type stars some of which show evidence of circumstellar dust shells. Seven sources are previously uncataloged stars. K and M stars without circumstellar dust shells, M stars with circumstellar dust shells, and carbon stars occupy well-defined regions of infrared color-color diagrams.

Description: A 6-solar luminosity dust-embedded precursor of a low-mass (about 1 solar mass) pre-main-sequence star has been discovered with IRAS near the northeast lobe of the bipolar outflow region in the dust cloud L1551 and designated L1551 NE. Star formation is proceeding in at least two locations in L1551, reminiscent of the situation in regions of more massive star formation. If the position of NE in the flow from IRS 5 is indicative of the flow having initiated star formation in NE, then the object can be only about 24,000 years old. Alternatively, NE could appear by chance to lie in the flow from IRS 5. In the globule ES 0210-6A, a 12 solar luminosity dust-embedded precursor of a low-mass (about 1 solar mass) pre-main-sequence star is found which drives the bipolar flow responsible for the string of Herbig-Haro objects HH 46-47 A-D. In this globule, there is only one region of active star formation.

Description: Observations of the dark cloud Barnard 5 show two compact sources of radiation within the dense core. IRS 1 is associated with 30-800 K dust, has a total luminosity of about 10 solar luminosities, and is presumably a newly formed star of roughly solar mass. IRS 2 has a much cooler color temperature, approximately 25 K, and emits only 1.3 solar luminosities. Its status is unclear, but IRS 2 may be at a very early stage of gravitational collapse or a density enhancement within the cloud heated by the interstellar radiation field. Also within the confines of the cloud are two point sources, which, if associated with the cloud, each emit about 0.5 solar luminosities in the IRAS bands. These may be T Tauri stars, separated from the cloud but still enshrouded in dust shells.

Description: The present paper is concerned with a search for IRAS sources positionally associated with globular clusters. This search revealed a strong source with unusual infrared colors, IRAS 18333-2357, near the center of M22. M22 (NGC 6566) is a bright, nearby, metal-poor globular cluster. Attention is given to the observations, the mass and luminosity of IRAS 18333-2357, the mass-loss rate, and the nature of IRAS 18333-2357. It is concluded that IRAS 18333-2357 may possibly be a bipolar nebula similar to OH 0739-14 although element abundance arguments appear to favor a carbon-rich rather than oxygen-rich shell.

Description: Very sensitive IRAS observations of a region of 0.8 sq deg in the Chamaeleon I cloud have revealed 70 compact sources. Hot sources are field stars; warm sources are associated with pre-main-sequence (PMS) stars in the cloud center; others may be in an even earlier phase of gravitational collapse. Cool sources, detected only at the long wavelengths, surround the main cloud and appear to be associated with small globules. Only a small fraction (less than 20 percent) of the total luminosity of the known PMS objects is emitted in the IRAS bands. This has important implications for the classification of the newly discovered embedded objects.

Description: The Lunar Reconnaissance Orbiter (LRO) launched in 2009 to collect the dataset required for future surface missions and to answer key questions about the lunar surface environment. In the first seven years of operations, the Lunar Reconnaissance Orbiter Camera (LROC) acquired over a million images of the lunar surface and collected key stereo observations for the production of meter-scale digital terrain models. Due to the configuration of the LRO orbit, LROC and the other onboard instruments have the opportunity to acquire observations at or near the poles every two hours. The lunar south polar region is an area of interest for future surface missions due to the benign thermal environment and areas of near-continuous illumination. These persistently illuminated regions are also adjacent to permanently shadowed areas (e.g. floors of craters and local depressions) that are of interest to both scientists and engineers prospecting for cold-trapped volatiles on or near the surface for future in situ resource utilization. Using a terramechanics model based on surface properties derived during the Apollo and Luna missions, we evaluated the accessibility of different science targets and the optimal traverse paths for a given set of waypoints. Assuming a rover that relies primarily on solar power, we identified a traverse that would keep the rover illuminated for 94.43% of the year between 1 January 2021 and 31 December 2021. Throughout this year-long period, the longest eclipse endured by the rover would last only 101 hours and the rover would move a total of 22.11 km with an average speed of 2.5 m/hr (max speed=30 m/hr). During this time the rover would be able to explore a variety of targets along the connecting ridge between Shackleton and de Gerlache craters. In addition to the southern polar regions, we are also examining traverses around other key exploration sites such as Marius Hills, Ina-D, Rima Parry, and the Mairan Domes in efforts to aid future mission planners and assess the requirements for future roving prospectors (e.g., maximum speed, maximum slope, etc.).

Description: Single photon counting and fast coincidence system in nuclear physics experiment involving two body luminescent reaction

Description: We present 10 micrometer images of the multiple T Tauri star system UZ Tau taken with the Berkeley mid-infrared array camera at the United Kingdom Infrared Telescope (UKIRT) and evidence that UZ Tau E and W are a common proper pair. The mid-infrared emission is resolved for the first time into the two components UZ Tau E and UZ Tau W. The mid-infrared excess deduced for UZ Tau W appears to be much lower than that observed for UZ Tau E. This excess emission is consistent with an optically thin circumstellar disk in the case of UZ Tau W, whereas UZ Tau E's excess is consistent with an optically thick disk. We suggest that the close binary star pair in UZ Tau W is responsible for the observed difference between UZ Tau E and W's mid-infrared excess. In the proposed model, the binary star interacts with the local circumstellar disk environment and clears out much of the material inside its orbital radius (approximately 50 AU). As a result, the hot dust, observed at mid-infrared wavelengths, in UZ Tau W is suppressed compared to its 'wider' companion UZ Tau E. This scenario can also plausibly account for differences observed in UZ Tau E's and UZ Tau W's optical line strengths and profiles.