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 References of "Street, R. A"      in Complete repository Arts & humanities   Archaeology   Art & art history   Classical & oriental studies   History   Languages & linguistics   Literature   Performing arts   Philosophy & ethics   Religion & theology   Multidisciplinary, general & others Business & economic sciences   Accounting & auditing   Production, distribution & supply chain management   Finance   General management & organizational theory   Human resources management   Management information systems   Marketing   Strategy & innovation   Quantitative methods in economics & management   General economics & history of economic thought   International economics   Macroeconomics & monetary economics   Microeconomics   Economic systems & public economics   Social economics   Special economic topics (health, labor, transportation…)   Multidisciplinary, general & others Engineering, computing & technology   Aerospace & aeronautics engineering   Architecture   Chemical engineering   Civil engineering   Computer science   Electrical & electronics engineering   Energy   Geological, petroleum & mining engineering   Materials science & engineering   Mechanical engineering   Multidisciplinary, general & others Human health sciences   Alternative medicine   Anesthesia & intensive care   Cardiovascular & respiratory systems   Dentistry & oral medicine   Dermatology   Endocrinology, metabolism & nutrition   Forensic medicine   Gastroenterology & hepatology   General & internal medicine   Geriatrics   Hematology   Immunology & infectious disease   Laboratory medicine & medical technology   Neurology   Oncology   Ophthalmology   Orthopedics, rehabilitation & sports medicine   Otolaryngology   Pediatrics   Pharmacy, pharmacology & toxicology   Psychiatry   Public health, health care sciences & services   Radiology, nuclear medicine & imaging   Reproductive medicine (gynecology, andrology, obstetrics)   Rheumatology   Surgery   Urology & nephrology   Multidisciplinary, general & others Law, criminology & political science   Civil law   Criminal law & procedure   Criminology   Economic & commercial law   European & international law   Judicial law   Metalaw, Roman law, history of law & comparative law   Political science, public administration & international relations   Public law   Social law   Tax law   Multidisciplinary, general & others Life sciences   Agriculture & agronomy   Anatomy (cytology, histology, embryology...) & physiology   Animal production & animal husbandry   Aquatic sciences & oceanology   Biochemistry, biophysics & molecular biology   Biotechnology   Entomology & pest control   Environmental sciences & ecology   Food science   Genetics & genetic processes   Microbiology   Phytobiology (plant sciences, forestry, mycology...)   Veterinary medicine & animal health   Zoology   Multidisciplinary, general & others Physical, chemical, mathematical & earth Sciences   Chemistry   Earth sciences & physical geography   Mathematics   Physics   Space science, astronomy & astrophysics   Multidisciplinary, general & others Social & behavioral sciences, psychology   Animal psychology, ethology & psychobiology   Anthropology   Communication & mass media   Education & instruction   Human geography & demography   Library & information sciences   Neurosciences & behavior   Regional & inter-regional studies   Social work & social policy   Sociology & social sciences   Social, industrial & organizational psychology   Theoretical & cognitive psychology   Treatment & clinical psychology   Multidisciplinary, general & others     Showing results 1 to 20 of 30 1 2     A Super-Jupiter orbiting a late-type star: A refined analysis of microlensing event OGLE-2012-BLG-0406Tsapras, Y.; Choi, J.-Y.; Street, R. A. et alin Astrophysical Journal (2014), 782We present a detailed analysis of survey and follow-up observations of microlensing event OGLE-2012-BLG-0406 based on data obtained from 10 different observatories. Intensive coverage of the lightcurve ... [more ▼]We present a detailed analysis of survey and follow-up observations of microlensing event OGLE-2012-BLG-0406 based on data obtained from 10 different observatories. Intensive coverage of the lightcurve, especially the perturbation part, allowed us to accurately measure the parallax effect and lens orbital motion. Combining our measurement of the lens parallax with the angular Einstein radius determined from finite-source effects, we estimate the physical parameters of the lens system. We find that the event was caused by a $2.73\pm 0.43\ M_{\rm J}$ planet orbiting a $0.44\pm 0.07\ M_{\odot}$ early M-type star. The distance to the lens is $4.97\pm 0.29$\ kpc and the projected separation between the host star and its planet at the time of the event is $3.45\pm 0.26$ AU. We find that the additional coverage provided by follow-up observations, especially during the planetary perturbation, leads to a more accurate determination of the physical parameters of the lens. [less ▲]Detailed reference viewed: 57 (3 ULg) High-precision photometry by telescope defocussing - VI. WASP-24, WASP-25 andWASP-26*Southworth, J.; Hinse, T. C.; Burgdorf, M. et alin Monthly Notices of the Royal Astronomical Society (2014), 444(1), 776-789We present time series photometric observations of 13 transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three systems have orbital obliquity measurements, WASP-24 andWASP-26 have been ... [more ▼]We present time series photometric observations of 13 transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three systems have orbital obliquity measurements, WASP-24 andWASP-26 have been observed with Spitzer, andWASP-25 was previously comparatively neglected. Our light curves were obtained using the telescope-defocussing method and have scatters of 0.5-1.2 mmag relative to their best-fitting geometric models. We use these data to measure the physical properties and orbital ephemerides of the systems to high precision, finding that our improved measurements are in good agreement with previous studies. High-resolution Lucky Imaging observations of all three targets show no evidence for faint stars close enough to contaminate our photometry. We confirm the eclipsing nature of the star closest to WASP-24 and present the detection of a detached eclipsing binary within 4.25 arcmin of WASP-26. © 2014 The Authors. [less ▲]Detailed reference viewed: 21 (3 ULg) MOA-2010-BLG-311: A planetary candidate below the threshold of reliable detectionYee, J. C.; Hung, L.-W.; Bond, I. A. et alin Astrophysical Journal (2013), 769(1), 77We analyze MOA-2010-BLG-311, a high magnification (A_max>600) microlensing event with complete data coverage over the peak, making it very sensitive to planetary signals. We fit this event with both a ... [more ▼]We analyze MOA-2010-BLG-311, a high magnification (A_max>600) microlensing event with complete data coverage over the peak, making it very sensitive to planetary signals. We fit this event with both a point lens and a 2-body lens model and find that the 2-body lens model is a better fit but with only Delta chi^2~140. The preferred mass ratio between the lens star and its companion is \$q=10^(-3.7+/-0.1), placing the candidate companion in the planetary regime. Despite the formal significance of the planet, we show that because of systematics in the data the evidence for a planetary companion to the lens is too tenuous to claim a secure detection. When combined with analyses of other high-magnification events, this event helps empirically define the threshold for reliable planet detection in high-magnification events, which remains an open question. [less ▲]Detailed reference viewed: 30 (11 ULg) Microlensing Discovery of a Population of Very Tight, Very Low Mass Binary Brown DwarfsChoi, J.-Y.; Han, C.; Udalski, A. et alin Astrophysical Journal (2013), 768Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs (BDs) are poorly understood. The multiplicity properties and minimum mass of the BD ... [more ▼]Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs (BDs) are poorly understood. The multiplicity properties and minimum mass of the BD mass function provide critical empirical diagnostics of these mechanisms. We present the discovery via gravitational microlensing of two very low mass, very tight binary systems. These binaries have directly and precisely measured total system masses of 0.025 M [SUB]⊙[/SUB] and 0.034 M [SUB]⊙[/SUB], and projected separations of 0.31 AU and 0.19 AU, making them the lowest-mass and tightest field BD binaries known. The discovery of a population of such binaries indicates that BD binaries can robustly form at least down to masses of ~0.02 M [SUB]⊙[/SUB]. Future microlensing surveys will measure a mass-selected sample of BD binary systems, which can then be directly compared to similar samples of stellar binaries. [less ▲]Detailed reference viewed: 56 (1 ULg) EMCCD photometry reveals two new variable stars in the crowded central region of the globular cluster NGC 6981Skottfelt, J.; Bramich, D. M.; Figuera Jaimes, R. et alin Astronomy and Astrophysics (2013), 553Two previously unknown variable stars in the crowded central region of the globular cluster NGC 6981 are presented. The observations were made using the electron multiplying CCD (EMCCD) camera at the ... [more ▼]Two previously unknown variable stars in the crowded central region of the globular cluster NGC 6981 are presented. The observations were made using the electron multiplying CCD (EMCCD) camera at the Danish 1.54 m Telescope at La Silla, Chile. The two variableswere not previously detected by conventional CCD imaging because of their proximity to a bright star. This discovery demonstrates that EMCCDs are a powerful tool for performing high-precision time-series photometry in crowded fields and near bright stars, especially when combined with difference image analysis. Based on data collected by MiNDSTEp with the Danish 1.54 m telescope. [less ▲]Detailed reference viewed: 22 (4 ULg) A giant planet beyond the snow line in microlensing event OGLE-2011-BLG-0251Kains, N.; Street, R. A.; Choi, J.-Y. et alin Astronomy and Astrophysics (2013), 552
Aims: We present the analysis of the gravitational microlensing event OGLE-2011-BLG-0251. This anomalous event was observed by several survey and follow-up collaborations conducting microlensing ... [more ▼]
Aims: We present the analysis of the gravitational microlensing event OGLE-2011-BLG-0251. This anomalous event was observed by several survey and follow-up collaborations conducting microlensing observations towards the Galactic bulge.
Methods: Based on detailed modelling of the observed light curve, we find that the lens is composed of two masses with a mass ratio q = 1.9 × 10[SUP]-3[/SUP]. Thanks to our detection of higher-order effects on the light curve due to the Earth's orbital motion and the finite size of source, we are able to measure the mass and distance to the lens unambiguously.
Aims: MOA 2009-BLG-411 was detected on August 5, 2009 by the MOA-Collaboration. Alerted as a high-magnification event, it was sensitive to planets. Suspected anomalies in the light curve were not confirmed by a real-time model, but further analysis revealed small deviations from a single lens extended source fit.
Methods: Thanks to observations by all the collaborations, this event was well monitored. We first decided to characterize the source star properties by using a more refined method than the classical one: we measure the interstellar absorption along the line of sight in five different passbands (VIJHK). Secondly, we model the lightcurve by using the standard technique: make (s,q,α) grids to look for local minima and refine the results by using a downhill method (Markov chain Monte Carlo). Finally, we use a Galactic model to estimate the physical properties of the lens components.
Results: We find that the source star is a giant G star with radius 9 R[SUB]&sun;[/SUB]. The grid search gives two local minima, which correspond to the theoretical degeneracy s ≡ s[SUP]-1[/SUP]. We find that the lens is composed of a brown dwarf secondary of mass M[SUB]S[/SUB] = 0.05 M[SUB]&sun;[/SUB] orbiting a primary M-star of mass M[SUB]P[/SUB] = 0.18 M[SUB]&sun;[/SUB]. We also reveal a new mass-ratio degeneracy for the central caustics of close binaries.
Conclusions: As far as we are aware, this is the first detection using the microlensing technique of a binary system in our Galaxy composed of an M-star and a brown dwarf. Appendix is available in electronic form at http://www.aanda.org [less ▲]Detailed reference viewed: 30 (0 ULg) WASP-35b, WASP-48b and WASP-51b: Two new planets and an independent discovery of HAT-P-30bEnoch, B.; Anderson, D. R.; Barros, S. C. C. et alin Astronomical Journal (The) (2011), 142(3), 86We report the detection of WASP-35b, a planet transiting a metal-poor ([Fe/H] = -0.15) star in the Southern hemisphere, WASP-48b, an inflated planet which may have spun-up its slightly evolved host star ... [more ▼]We report the detection of WASP-35b, a planet transiting a metal-poor ([Fe/H] = -0.15) star in the Southern hemisphere, WASP-48b, an inflated planet which may have spun-up its slightly evolved host star of 1.75 R_sun in the Northern hemisphere, and the independent discovery of HAT-P-30b / WASP-51b, a new planet in the Northern hemisphere. Using WASP, RISE, FTS and TRAPPIST photometry, with CORALIE, SOPHIE and NOT spectroscopy, we determine that WASP-35b has a mass of 0.72 +/- 0.06 M_J and radius of 1.32 +/- 0.03 R_J, and orbits with a period of 3.16 days, WASP-48b has a mass of 0.98 +/- 0.09 M_J, radius of 1.67 +/- 0.08 R_J and orbits in 2.14 days, while WASP-51b, with an orbital period of 2.81 days, is found to have a mass of 0.76 +/- 0.05 M_J and radius of 1.42 +/- 0.04 R_J, agreeing with values of 0.71 +/- 0.03 M_J and 1.34 +/- 0.07 R_J reported for HAT-P-30b. [less ▲]Detailed reference viewed: 28 (4 ULg) WASP-31b: a low-density planet transiting a metal-poor, late-F-type dwarf starAnderson, D. R.; Collier Cameron, A.; Hellier, C. et alin Astronomy and Astrophysics (2011), 531We report the discovery of the low-density, transiting giant planet WASP-31b. The planet is 0.47 Jupiter masses and 1.56 Jupiter radii. It is in a 3.4-day orbit around a 1-Gyr-old, late-F-type, V = 11.7 ... [more ▼]We report the discovery of the low-density, transiting giant planet WASP-31b. The planet is 0.47 Jupiter masses and 1.56 Jupiter radii. It is in a 3.4-day orbit around a 1-Gyr-old, late-F-type, V = 11.7 star, which is a member of a common proper motion pair. In terms of its low density, WASP-31b is second only to WASP-17b, which is a more highly irradiated planet of similar mass. [less ▲]Detailed reference viewed: 10 (2 ULg) MOA-2009-BLG-387Lb: a massive planet orbiting an M dwarfBatista, V.; Gould, A.; Dieters, S. et alin Astronomy and Astrophysics (2011), 529
Aims: We report the discovery of a planet with a high planet-to-star mass ratio in the microlensing event MOA-2009-BLG-387, which exhibited pronounced deviations over a 12-day interval, one of the ... [more ▼]
Aims: We report the discovery of a planet with a high planet-to-star mass ratio in the microlensing event MOA-2009-BLG-387, which exhibited pronounced deviations over a 12-day interval, one of the longest for any planetary event. The host is an M dwarf, with a mass in the range 0.07 M[SUB]&sun;[/SUB] < M[SUB]host[/SUB] < 0.49 M[SUB]&sun;[/SUB] at 90% confidence. The planet-star mass ratio q = 0.0132 ± 0.003 has been measured extremely well, so at the best-estimated host mass, the planet mass is m[SUB]p[/SUB] = 2.6 Jupiter masses for the median host mass, M = 0.19 M[SUB]&sun;[/SUB].
Methods: The host mass is determined from two "higher order" microlensing parameters. One of these, the angular Einstein radius θ[SUB]E[/SUB] = 0.31 ± 0.03 mas has been accurately measured, but the other (the microlens parallax π[SUB]E[/SUB], which is due to the Earth's orbital motion) is highly degenerate with the orbital motion of the planet. We statistically resolve the degeneracy between Earth and planet orbital effects by imposing priors from a Galactic model that specifies the positions and velocities of lenses and sources and a Kepler model of orbits.
Results: The 90% confidence intervals for the distance, semi-major axis, and period of the planet are 3.5 kpc < D[SUB]L[/SUB] < 7.9 kpc, 1.1 AU < a < 2.7 AU, and 3.8 yr < P < 7.6 yr, respectively. Photometric data is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/529/A102 [less ▲]Detailed reference viewed: 26 (3 ULg) WASP-41b: A transiting hot Jupiter planet orbiting a magnetically-active G8V starMaxted, P. F. L.; Anderson, D. R.; Collier Cameron, A. et alin Publications of the Astronomical Society of the Pacific [=PASP] (2011), 123We report the discovery of a transiting planet with an orbital period of 3.05d orbiting the star TYC 7247-587-1. The star, WASP-41, is a moderately bright G8V star (V=11.6) with a metallicity close to ... [more ▼]We report the discovery of a transiting planet with an orbital period of 3.05d orbiting the star TYC 7247-587-1. The star, WASP-41, is a moderately bright G8V star (V=11.6) with a metallicity close to solar ([Fe/H]=-0.08+-0.09). The star shows evidence of moderate chromospheric activity, both from emission in the cores of the CaII H and K lines and photometric variability with a period of 18.3d and an amplitude of about 1%. The rotation period of the star implies a gyrochronological age for WASP-41 of 1.8Gyr with an error of about 15%. We have used a combined analysis of the available photometric and spectroscopic data to derive the mass and radius of the planet (0.93+-0.06M_Jup, 1.21+-0.06R_Jup). Further observations of WASP-41 can be used to explore the connections between the properties of hot Jupiter planets and the level of chromospheric activity in their host stars. [less ▲]Detailed reference viewed: 12 (0 ULg) WASP-25b: a 0.6 M-J planet in the Southern hemisphereEnoch, B.; Cameron, A Collier; Anderson, D. R. et alin Monthly Notices of the Royal Astronomical Society (2011), 410(3), 16311636We report the detection of a 0.6 M-J extrasolar planet by WASP-South, WASP-25b, transiting its solar-type host star every 3.76d. A simultaneous analysis of the WASP, FTS and Euler photometry and CORALIE ... [more ▼]We report the detection of a 0.6 M-J extrasolar planet by WASP-South, WASP-25b, transiting its solar-type host star every 3.76d. A simultaneous analysis of the WASP, FTS and Euler photometry and CORALIE spectroscopy yields a planet of R[SUB]p[/SUB] = 1.22 R[SUB]J[/SUB] and M[SUB]p[/SUB] = 0.58 M[SUB]J[/SUB] around a slightly metal-poor solar-type host star, [Fe/H] = - 0.05 +/- 0.10, of R[SUB]*[/SUB] = 0.92 R[SUB]solar[/SUB] and M[SUB]*[/SUB] = 1.00 M[SUB]solar[/SUB]. WASP-25b is found to have a density of ρ[SUB]p[/SUB] = 0.32 ρ[SUB]J[/SUB], a low value for a sub-Jupiter mass planet. We investigate the relationship of planetary radius to planetary equilibrium temperature and host star metallicity for transiting exoplanets with a similar mass to WASP-25b, finding that these two parameters explain the radii of most low-mass planets well. [less ▲]Detailed reference viewed: 21 (4 ULg) 1 2