206 research outputs found
High-Spatial-Resolution K-Band Imaging of Select K2 Campaign Fields
NASA's K2 mission began observing fields along the ecliptic plane in 2014.
Each observing campaign lasts approximately 80 days, during which
high-precision optical photometry of select astrophysical targets is collected
by the Kepler spacecraft. Due to the 4 arcsec pixel scale of the Kepler
photometer, significant blending between the observed targets can occur
(especially in dense fields close to the Galactic plane). We undertook a
program to use the Wide Field Camera (WFCAM) on the 3.8 m United Kingdom
InfraRed Telescope (UKIRT) to collect high-spatial-resolution near-infrared
images of targets in select K2 campaign fields, which we report here. These 0.4
arcsec resolution K-band images offer the opportunity to perform a variety of
science, including vetting exoplanet candidates by identifying nearby stars
blended with the target star and estimating the size, color, and type of
galaxies observed by K2.Comment: 2 pages, Published by Research Notes of the American Astronomical
Societ
Combining noise mapping and ventilation performance for non-domestic buildings in an urban area
Maximising the natural ventilation of a building can be beneficial in terms of comfort and reduced reliance on air-conditioning. However, in urban areas this can conflict with the need to reduce the ingress of external noise. In this paper a method is presented to quantify the interaction of building noise exposure with natural ventilation potential. Finite element models of ventilation aperture sound reduction index were used to determine façade sound insulation values for naturally ventilated buildings in two locations. Road traffic noise levels at the building façade were obtained from a calculated noise map of Manchester (UK). Window openings were adjusted in the thermal simulation package and modelled with mixed mode cooling ventilation strategies (both natural and mechanical). This enabled noise considerations to be quantified in terms of building ventilation and energy use for cooling at the whole building level. For a tolerated internal road noise ingress of 34 dB(A) cooling energy consumption for the example buildings in the quieter noise locations was found to decrease by 22%–45% compared to the noisier locations. Most importantly, the introduction of noise reduction measures equal to 10 dB(A) resulted in reductions in cooling energy consumption that varied from 28% to 45% of the original cooling energy consumption. This study illustrates the importance of an integrated approach to both noise exposure and ventilation performance in urban buildings
Kepler Observations of V447 Lyr: An Eclipsing U Gem Cataclysmic Variable
We present the results of an analysis of data covering 1.5 years of the dwarf
nova V447 Lyr. We detect eclipses of the accretion disk by the mass donating
secondary star every 3.74 hrs which is the binary orbital period. V447 Lyr is
therefore the first dwarf nova in the Kepler field to show eclipses. We also
detect five long outbursts and six short outbursts showing V447 Lyr is a U Gem
type dwarf nova. We show that the orbital phase of the mid-eclipse occurs
earlier during outbursts compared to quiescence and that the width of the
eclipse is greater during outburst. This suggests that the bright spot is more
prominent during quiescence and that the disk is larger during outburst than
quiescence. This is consistent with an expansion of the outer disk radius due
to the presence of high viscosity material associated with the outburst,
followed by a contraction in quiescence due to the accretion of low angular
momentum material. We note that the long outbursts appear to be triggered by a
short outburst, which is also observed in the super-outbursts of SU UMa dwarf
novae as observed using Kepler.Comment: Accepted by MNRA
A Class of Eccentric Binaries with Dynamic Tidal Distortions Discovered with Kepler
We have discovered a class of eccentric binary systems within the Kepler data
archive that have dynamic tidal distortions and tidally-induced pulsations.
Each has a uniquely shaped light curve that is characterized by periodic
brightening or variability at time scales of 4-20 days, frequently accompanied
by shorter period oscillations. We can explain the dominant features of the
entire class with orbitally-varying tidal forces that occur in close, eccentric
binary systems. The large variety of light curve shapes arises from viewing
systems at different angles. This hypothesis is supported by spectroscopic
radial velocity measurements for five systems, each showing evidence of being
in an eccentric binary system. Prior to the discovery of these 17 new systems,
only four stars, where KOI-54 is the best example, were known to have evidence
of these dynamic tides and tidally-induced oscillations. We perform preliminary
fits to the light curves and radial velocity data, present the overall
properties of this class and discuss the work required to accurately model
these systems.Comment: 13 pages, submitted to Ap
Living in uncertain times: trajectories to death in residential care homes.
BACKGROUND: Older people living in care homes often have limited life expectancy. Practitioners and policymakers are increasingly questioning the appropriateness of many acute hospital admissions and the quality of end-of-life care provided in care homes. AIM: To describe care home residents' trajectories to death and care provision in their final weeks of life. DESIGN AND SETTING: Prospective study of residents in six residential care homes in three sociodemographically varied English localities: Hertfordshire, Essex, and Cambridgeshire. METHOD: Case note reviews and interviews with residents, care home staff, and healthcare professionals. RESULTS: Twenty-three out of 121 recruited residents died during the study period. Four trajectories to death were identified: 'anticipated dying' with an identifiable end-of-life care period and death in the care home (n = 9); 'unexpected dying' with death in the care home that was not anticipated and often sudden (n = 3); 'uncertain dying' with a period of diagnostic uncertainty or difficult symptom management leading to hospital admission and inpatient death (n = 7); and 'unpredictable dying' with an unexpected event leading to hospital admission and inpatient death (n = 4). End-of-life care tools were rarely used. Most residents who had had one or more acute hospital admission were still alive at the end of the study. CONCLUSION: For some care home residents there was an identifiable period when they were approaching the end-of-life and planned care was put in place. For others, death came unexpectedly or during a period of considerable uncertainty, with care largely unplanned and reactive to events
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