Ultraviolet geometric albedo of Uranus

The purpose was to obtain ultraviolet flux measurements of Uranus before and after the January 1986 flyby past Uranus by Voyager. These measurements were used to determine absolute flux distributions in the wavelength range 1950 to 3200 A. This wavelength range is an important region to observe since the model atmospheres for Uranus indicate that the albedo spectrum in this region can tightly constrain the height of the photochemical haze layer

Absolute optical flux observations of the 18 October 1967 total eclipse of the moon

Absolute optical flux observations of total moon eclipse on 18 October 196

Fundamental spectrophotometry of the major planets Progress report, 1 Jun. 1970 - 1 Feb. 1971

Spectrophotometry of Neptune, Uranus, and Plut

JHK Imaging and Photometry of Low z QSOs and Radio Galaxy

We describe J,H,K deep imaging of 90 arcmin fields around 4 QSOs and one Radio galaxy at redshifts in the range 0.06 to 0.30, and show their images, luminosity profiles, and NIR 2-colour diagrams of objects. We find that the QSO hosts are all resolved, and compare them with previous CCD images. The host galaxy colours are consistent with old and young stellar populations at the QSO redshift. The colours of nearby galaxies suggest that all the AGN live in groups of generally smaller companion galaxies, mostly with evolved populations at the same redshift. The two radio-loud objects live in richer cluster environments than the others. Gissel population models indicate reddening in the galaxies, star-forming regions, and possibly a systematic H-K offset. The QSO luminosity profiles are complex and reveal some of their tidal disturbance and star-formation history.Comment: 22 pages of text (latex), 2 tables )latex), and 15 figures (postscript). Accepted for publication in AJ, February 1997. Also available at http://www.dao.nrc.ca/DAO/SCIENCE/science.htm

A Supernova Factory in the Merger System Arp 299

We have imaged the nearby galaxy merger Arp 299 at arcsecond and milliarcsecond resolution, using both the Very Large Array and the Very Long Baseline Array. The large-scale radio emission from the merger contains 5 bright, compact radio sources embedded in diffuse emission, with diameters less than 200 pc. Supernova rates of 0.1 to 1 per year are required to produce the VLA-detected radio emission in these sources. Two of the compact VLA radio sources, designated Source A and Source D, also have been detected and imaged at milliarcsecond scales. Source A, which is associated with the nucleus of one of the merging galaxies, contains five milliarcsecond-scale sources, each with a radio power between 100 and 1000 times that of the Galactic supernova remnant Cassiopeia A. Four of these have flat or inverted spectra and appear to be young supernovae. Three of the VLBI-scale sources are located within 10 pc (projected) of one another, and two are separated by less than 3 pc, indicating that they all may be within the same super starcluster or complex of such clusters. The brightest VLBI-scale source, A0, has an extremely inverted pectrum, with alpha larger than +2 at gigahertz frequencies. It seems to be the youngest supernova, which has not yet broken out of its circumstellar shell. The milliarcsecond radio sources within Source A appear to constitute a upernova factory, confirming the presence of an extreme starburst that peaked at least a few million years ago.Comment: Accepted for the Astrophysical Journal, 22 pages, 10 figure

Evolution of luminous IRAS galaxies: Radio imaging

In a recent study of IRAS galaxies' optical morphologies, we found that luminous IR sources lie in the IR color-luminosity plane in groups which separate out by optical spectroscopic type and also by degree of tidal disturbance. We found that the most luminous steep-IR-spectrum sources are generally galaxies in the initial stages of a major tidal interaction. Galaxies with active nuclei were generally found to have flatter IR spectra, to cover a range of IR luminosity, and to be in the later stages of a tidal interaction. We proposed a sequence of events by which luminous IR sources evolve: they start as interacting or merging galaxies, some develop active nuclei, and most undergo extensive star-formation in their central regions. Another way to study these objects and their individual evolution is to study their radio morphologies. Radio emission may arise at a detectable level from supernovae in star-forming regions and/or the appearance of an active nucleus can be accompanied by a nuclear radio source (which may develop extended structure). Therefore, the compact radio structure may trace the evolution of the inner regions of IRAS-luminous sources. If the radio sources are triggered by the interactions, we would expect to find the radio morphology related to the optical 'interactivity' of the systems. Here, we explore using the radio emission of IRAS galaxies as a possible tracer of galaxy evolution. We present and discuss observations of the compact radio morphology of 111 luminous IRAS-selected active galaxies covering a wide range of IR and optical properties

The Five Hazardous Attitudes, A Subset of Complacency

Abstract The article discusses complacency and the five hazardous attitudes in the context that the five hazardous attitudes are a subset of complacency. On the list of 12 most common contributors to aircraft accidents, the FAA lists complacency as the second most often contributor. Complacency implies that there is a level of satisfaction with the present circumstances without any consideration of future unseen potential dangers. Attitude embodies the concept that a person has a predisposed response to certain stimuli. Complacency manifests itself in the form of the five hazardous attitudes: (a) anti-authority, (b) impulsivity, (c) invulnerability, (d) macho, and (e) resignation. Analysis of the 2001 Gulfstream III accident in Aspen, CO revealed disregard for federal, state, and local regulations in addition to the violation of company policies. The crew executed a prohibited approach and descended below the minimum descent altitude without the proper visual cues. The crew knew the correct protocols, but they chose to disregard them. The crew of the GIV accident in Bedford, MA neglected to complete the five required checklists including the Before Starting Engines checklist to the Lineup checklist on 98% of the previous 175 flights. The crew attempted this takeoff with the flight controls locked. During their respective flight segments, each crew exhibited the five hazardous attitudes. Both crews knew the correct standards of performance although neither crew met those standards. Both crews were professionally trained and experienced. The respective flight crews were complacent, and they exhibited that complacency through the five hazardous attitudes

Crew Resource Management for Large Unmanned Aircraft Systems Operations

Abstract The author explored the application of crew resource management (CRM) principles to commercial flight operations conducted by large unmanned aircraft systems (UAS). Currently, there is no regulatory structure governing the operation of large UAS in commercial flight operations. However, the National Aeronautics and Space Administration (NASA) forecasted the future by demonstrating the feasibility of large remotely piloted UAS flight in June 2018 by flying Ikhana, a modified MQ-9 Predator B aircraft, over a 415-mile route in Class A and in Class E airspace over southern California (Kooser, 2018). Ikhana is a 10,500-pound aircraft with a wingspan of 66 feet capable of climbing to 40,000 feet. In order to establish the viability of CRM as an element of a safety management system to mitigate human factors errors, the research used a cross-case analysis by Neff (2016) of four large UAS accidents to derive a ranked list of the eight most prevalent hard-skill and soft-skill human errors identified as causal to the accidents. An additional study of five Indian Air Force UAS accidents by Sharma and Chakravarti (2005) was referenced and listed eight primarily soft-skill human factors contributing factors. The author applied a CRM teamwork centered template using communications and workload management inputs and situational awareness and threat and error management outputs to analyze and propose mitigations to the contributing human factors errors. The author concluded that a safety management system incorporating CRM principles and supported by appropriate leadership philosophy, policies, procedures, and best practices is an essential element to combat human factors errors and facilitate safe integration of large commercial UAS flight operations into joint use national airspace

Treatment of metal surfaces for use with space storable propellants - A critical survey

Treatment of metallic surfaces for use with space storable propellant