R. A. Street
A5042337812- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- History and Developments in Astronomy
- Scientific Computing and Data Management
- Pulsars and Gravitational Waves Research
- Distributed and Parallel Computing Systems
- Atmospheric chemistry and aerosols
- Spacecraft Design and Technology
- Plant responses to elevated CO2
- Space Exploration and Technology
- Historical and Cultural Archaeology Studies
- Cultural Heritage Management and Preservation
- Calibration and Measurement Techniques
- Spectroscopy and Laser Applications
- Technology Assessment and Management
- Atmospheric and Environmental Gas Dynamics
- Astrophysics and Cosmic Phenomena
- Superconducting and THz Device Technology
Las Cumbres Observatory Global Telescope Network
2015-2024
Lowcountry Council of Governments
2022
Heidelberg University
2021
Lac Courte Oreilles Ojibwa Community College
2019
Queen Mary University of London
2016
University of California, Santa Barbara
2008-2012
Queen's University Belfast
2004-2007
University of St Andrews
2002-2003
Queens University
2003
Queen's University
2003
Las Cumbres Observatory Global Telescope (LCOGT) is a young organization dedicated to time-domain observations at optical and (potentially) near-IR wavelengths. To this end, LCOGT constructing worldwide network of telescopes, including the two 2 m Faulkes as many 17 × 1 23 40 cm telescopes. These telescopes initially will be outfitted for imaging (excepting telescopes) spectroscopy wavelengths between atmospheric UV cutoff roughly 1-μm limit silicon detectors. Since first LCOGT's are now...
We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with aim of measuring masses black holes in 12 nearby (z < 0.05) Seyfert 1 galaxies expected range ~10^6-10^7 M_sun and also well-studied active galactic nucleus (AGN) NGC 5548. Nine objects sample (including 5548) showed optical variability sufficient strength during to allow for time lag be measured between continuum fluctuations response these broad Hbeta emission. present...
We present the first measurement of planet frequency beyond "snow line," for planet-to-star mass-ratio interval −4.5 < log q −2, corresponding to range ice giants gas giants. find at mean mass ratio = 5 × 10−4 with no discernible deviation from a flat (Öpik's law) distribution in log-projected separation s. The determination is based on sample six planets detected intensive follow-up observations high-magnification (A>200) microlensing events during 2005–2008. sampled host stars have typical...
We present the discovery of KELT-1b, first transiting low-mass companion from wide-field Kilodegree Extremely Little Telescope-North (KELT-North) survey. The V=10.7 primary is a mildly evolved, solar-metallicity, mid-F star. brown dwarf or super-massive planet with mass 27.23+/-0.50 MJ and radius 1.110+0.037-0.024 RJ, on very short period (P=1.21750007) circular orbit. KELT-1b receives large amount stellar insolation, an equilibrium temperature assuming zero albedo perfect redistribution...
The Wide Field Infrared Survey Telescope (WFIRST) is a 2.4m space telescope with 0.281 deg^2 field of view for near-IR imaging and slitless spectroscopy coronagraph designed > 10^8 starlight suppresion. As background information Astro2020 white papers, this article summarizes the current design anticipated performance WFIRST. While WFIRST does not have UV imaging/spectroscopic capabilities Hubble Space Telescope, wide surveys hundreds times more efficient. Some most ambitious multi-cycle...
Abstract We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). used Hubble Space Telescope (HST) to carry out precise astrometry source star long-duration ( t E ≃ 270 days), high-magnification microlensing event MOA-2011-BLG-191/OGLE-2011-BLG-0462 (hereafter designated as MOA-11-191/OGLE-11-462), in direction Galactic bulge. HST imaging, conducted at eight epochs over interval 6 yr, reveals a clear relativistic astrometric deflection...
We present the first example of binary microlensing for which parameter measurements can be verified (or contradicted) by future Doppler observations. This test is made possible a confluence two relatively unusual circumstances. First, lens bright enough (I=15.6) to permit measurements. Second, we measure not only usual 7 binary-lens parameters, but also 'microlens parallax' (which yields mass) and components instantaneous orbital velocity. Thus measure, effectively, 6 'Kepler+1' parameters...
Kepler observations of the star HD 187091 (KIC 8112039, hereafter KOI-54) revealed a remarkable light curve exhibiting sharp periodic brightening events every 41.8 days with superimposed set oscillations forming beating pattern in phase brightenings. Spectroscopic that this is binary highly eccentric orbit, e = 0.83. We are able to match and radial velocities nearly face-on (i 55) model which caused by tidal distortion irradiation identical A stars during their close periastron passage. The...
We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with aim of measuring masses black holes in 12 nearby (z < 0.05) Seyfert 1 galaxies expected range ~10^6-10^7M_sun and also well-studied active galactic nucleus (AGN) NGC 5548. Nine objects sample (including 5548) showed optical variability sufficient strength during to allow for time lag be measured between continuum fluctuations response these broad Hbeta emission, which we...
Parallax is the most fundamental technique for measuring distances to astronomical objects. Although terrestrial parallax was pioneered over 2000 years ago by Hipparchus (ca. 140 B.C.E.) measure distance Moon, baseline of Earth so small that can generally only be applied objects in Solar System. However, there exists a class extreme gravitational microlensing events which effects readily detected and permit measurement distance, mass, transverse velocity lens. Here we report observations...
We present the discovery and mass measurement of cold, low-mass planet MOA-2009-BLG-266Lb, performed with gravitational microlensing method. This has a mp = 10.4 ± 1.7 M⊕ orbits star M⋆ 0.56 0.09 M☉ at semimajor axis AU an orbital period yrs. The host measurements are enabled by parallax effect, which is seen primarily in light curve distortion due to motion Earth. But analysis also demonstrates capability measure Deep Impact (or EPOXI) spacecraft heliocentric orbit. distance similar...
The Large Synoptic Survey Telescope is designed to provide an unprecedented optical imaging dataset that will support investigations of our Solar System, Galaxy and Universe, across half the sky over ten years repeated observation. However, exactly how LSST observations be taken (the observing strategy or "cadence") not yet finalized. In this dynamically-evolving community white paper, we explore detailed performance anticipated science expected depend on small changes strategy. Using...
We present the analysis of first circumbinary planet microlensing event, OGLE-2007-BLG-349. This event has a strong planetary signal that is best fit with mass ratio $q \approx 3.4\times10^{-4}$, but there an additional due to lens mass, either another or star. find acceptable light curve fits two classes models: 2-planet models (with single host star) and models. The also reveals significant parallax effect, which constrains system be $M_L 0.7 M_\odot$. Hubble Space Telescope images resolve...
We report the detection of a Cold Neptune m_planet=21+/-2MEarth orbiting 0.38MSol M dwarf lying 2.5-3.3 kpc toward Galactic center as part campaign combining ground-based and Spitzer observations to measure distribution planets. This is first time that complex real-time protocols described by Yee et al. (2015), which aim maximize planet sensitivity while maintaining sample integrity, have been carried out in practice. Multiple survey follow-up teams successfully combined their efforts within...
Vera C. Rubin Observatory is a ground-based astronomical facility under construction, joint project of the National Science Foundation and U.S. Department Energy, designed to conduct multi-purpose 10-year optical survey southern hemisphere sky: Legacy Survey Space Time. Significant flexibility in strategy remains within constraints imposed by core science goals probing dark energy matter, cataloging Solar System, exploring transient sky, mapping Milky Way. The survey's massive data...
Abstract RoboNet‐II uses a global network of robotic telescopes to perform follow‐up observations microlensing events in the Galactic Bulge. The current consists three 2 m located Hawaii and Australia (owned by Las Cumbres Observatory) Canary Islands Liverpool John Moores University). In future years will be expanded deploying clusters 1 other suitable locations. A principal scientific aim project is detection cool extra‐solar planets method gravitational microlensing. These detections...
Abstract Within less than 15 years, the count of known planets orbiting stars other Sun has risen from none to more 400 with detections arising four successfully applied techniques: Doppler‐wobbles, planetary transits, gravitational microlensing, and direct imaging. While hunt for twin Earths is on, a statistically well‐defined sample population in all their variety required probing models planet formation orbital evolution so that origin harbour life, like including ours, can be understood....
We present time-series photometric observations of thirteen transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three have orbital obliquity measurements, WASP-24 WASP-26 been observed with Spitzer, was previously comparatively neglected. Our light curves were obtained using telescope-defocussing method scatters 0.5 to 1.2 mmag relative their best-fitting geometric models. used these data measure physical properties ephemerides high precision, finding that our improved...
We present a general framework for matching the point-spread function (PSF), photometric scaling and sky background between two images, subject which is commonly referred to as difference image analysis (DIA). introduce new concept of spatially varying scale factor will be important DIA applied wide-field imaging data in order adapt transparency airmass variations across field-of-view. Furthermore, we demonstrate how separately control degree spatial variation each kernel basis function,...
We report the discovery of KELT-7b, a transiting hot Jupiter with mass MJ, radius RJ, and an orbital period days. The bright host star (HD 33643; KELT-7) is F-star V = 8.54, Teff 6789 K, [Fe/H] , . It has M⊙, R⊙, fifth most massive, hottest, ninth brightest known to planet. also around which Kilodegree Extremely Little Telescope (KELT) discovered Thus, KELT-7b ideal target for detailed characterization given its relatively low surface gravity, high equilibrium temperature, star. rapid...
Observations of accretion disks around young brown dwarfs (BDs) have led to the speculation that they may form planetary systems similar normal stars. While there been several detections planetary-mass objects BDs (2MASS 1207-3932 and 2MASS 0441-2301), these companions relatively large mass ratios projected separations, suggesting formed in a manner analogous stellar binaries. We present discovery object orbiting field BD via gravitational microlensing, OGLE-2012-BLG-0358Lb. The system is...
We present microlens parallax measurements for 21 (apparently) isolated lenses observed toward the Galactic bulge that were imaged simultaneously from Earth and Spitzer, which was ∼1 AU west of in projection. combine these with a kinematic model Galaxy to derive distance estimates each lens, error bars are small compared Sun's galactocentric distance. The ensemble therefore yields well-defined cumulative distribution lens distances. In principle, it is possible compare this against set...
WASP-80 is one of only two systems known to contain a hot Jupiter which transits its M-dwarf host star. We present eight light curves transit event, obtained simultaneously using defocussed telescopes. These data were taken through the Bessell I, Sloan griz and near-infrared JHK passbands. use our search for opacity-induced changes in planetary radius, but find that all values agree with each other. Our are therefore consistent flat transmission spectrum within observational uncertainties....