Bryce Croll

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Nitrate concentrations in UK waters are rising, with the highest levels occurring in the south and east of England, particularly Lincolnshire, Cambridgeshire and East Anglia. The source of the nitrate is arable agriculture where intensification in the last few decades has increased nitrate leaching from soils into both surface and underground waters.(More)
We present multiwavelength, multi-telescope, ground-based follow-up photometry of the white dwarf WD 1145+017, that has recently been suggested to be orbited by up to six or more, short-period, lowmass, disintegrating planetesimals. We detect 9 significant dips in flux of between 10% and 30% of the stellar flux from our ground-based photometry. We observe(More)
We have made a comprehensive transit search for exoplanets down to ≃1.5 2 Earth radii in the HD 189733 system, based on 21-days of nearly uninterrupted broadband optical photometry obtained with the MOST (Microvariability & Oscillations of STars) satellite in 2006. We have searched these data for realistic limb-darkened transits from exoplanets other than(More)
We have designed, constructed, and tested an InGaAs near-infrared camera to explore whether low-cost detectors can make small (≤1 m) telescopes capable of precise (<1 mmag) infrared photometry of relatively bright targets. The camera is constructed around the 640x512 pixel APS640C sensor built by FLIR Electro-Optical Components. We designed custom(More)
Context. Asteroseismology has great potential for the study of metal-poor stars due to its sensitivity to determine stellar ages. Solid detections of oscillation frequencies in stars with well constrained fundamental parameters, combined with a known rotation period, should significantly advance our understanding of stellar structure and evolution in(More)
We first reported evidence for differential rotation of κ Ceti in Paper I. In this paper we demonstrate that the differential rotation pattern closely matches that for the Sun. This result is based on additional MOST (Microvariability & Oscillations of STars) observations in 2004 and 2005, to complement the 2003 observations discussed in Paper I. Using(More)
We have made a comprehensive transit search for exoplanets down to about 2 Earth radii in the HD 209458 system, based on nearly uninterrupted broadband optical photometry obtained with the MOST (Microvariability and Oscillations of Stars) satellite, spanning 14 days in 2004 and 44 days in 2005. We have searched these data for limb-darkened transits at(More)
We present ground-based observations from the Discovery Channel Telescope (DCT) of three transits of Kepler445c—a supposed super-Earth exoplanet with properties resembling GJ 1214b—and demonstrate that the transit depth is ∼50% shallower than the depth previously inferred from Kepler spacecraft data. The resulting decrease in planetary radius significantly(More)
We present multiwavelength photometry, high angular resolution imaging, and radial velocities of the unique and confounding disintegrating low-mass planet candidate KIC 12557548b. Our high angular resolution imaging, which includes space-based Hubble Space Telescope Wide Field Camera 3 (HST/WFC3) observations in the optical (∼0.53 μm and ∼0.77 μm), and(More)
Originally designed for night-vision equipment, InGaAs detectors are beginning to achieve background-limited performance in broadband imaging from the ground. The lower cost of these detectors can enable multi-band instruments, arrays of small telescopes, and large focal planes that would be uneconomical with high-performance HgCdTe detectors. We developed(More)