22 research outputs found
OGLE-2018-BLG-0022: A Nearby M-dwarf Binary
We report observations of the binary microlensing event OGLE-2018-BLG-0022, provided by the Robotic Observations of Microlensing Events (ROME)/Reactive Event Assessment (REA) Survey, which indicate that the lens is a low-mass binary star consisting of M3 (0.375 ± 0.020 M⊙) and M7 (0.098 ± 0.005 M⊙) components. The lens is unusually close, at 0.998 ± 0.047 kpc, compared with the majority of microlensing events, and despite its intrinsically low luminosity, it is likely that adaptive optics observations in the near future will be able to provide an independent confirmation of the lens masses
Spitzer Parallax Of Ogle-2015-blg-0966: A Cold Neptune In The Galactic Disk
We report the detection of a cold Neptune mplanet = 21 ± 2 M? orbiting a 0.38 M? M dwarf lying 2.5–3.3 kpc toward the Galactic center as part of a campaign combining ground-based and Spitzer observations to measure the Galactic distribution of planets. This is the first time that the complex real-time protocols described by Yee et al., which aim to maximize planet sensitivity while maintaining sample integrity, have been carried out in practice. Multiple survey and follow up teams successfully combined their efforts within the framework of these protocols to detect this planet. This is the second planet in the Spitzer Galactic distribution sample. Both are in the near to mid-disk and are clearly not in the Galactic bulge
Campaign 9 of the K2 Mission: Observational Parameters, Scientific Drivers, and Community Involvement for a Simultaneous Space- and Ground-based Microlensing Survey
K2's Campaign 9 (K2C9) will conduct a ~3.7 deg2 survey toward the Galactic bulge from 2016 April 22 through July 2 that will leverage the spatial separation between K2 and the Earth to facilitate measurement of the microlens parallax for microlensing events. These will include several that are planetary in nature as well as many short-timescale microlensing events, which are potentially indicative of free-floating planets (FFPs). These satellite parallax measurements will in turn allow for the direct measurement of the masses of and distances to the lensing systems. In this article we provide an overview of the K2C9 space- and ground-based microlensing survey. Specifically, we detail the demographic questions that can be addressed by this program, including the frequency of FFPs and the Galactic distribution of exoplanets, the observational parameters of K2C9, and the array of resources dedicated to concurrent observations. Finally, we outline the avenues through which the larger community can become involved, and generally encourage participation in K2C9, which constitutes an important pathfinding mission and community exercise in anticipation of WFIRST
The Spitzer Microlensing Program As A Probe For Globular Cluster Planets: Analysis Of Ogle-2015-BLG-0448
The microlensing event OGLE-2015-BLG-0448 was observed by Spitzer and lay within the tidal radius of the globular cluster NGC 6558. The event had moderate magnification and was intensively observed, hence it had the potential to probe the distribution of planets in globular clusters. We measure the proper motion of NGC 6558 () as well as the source and show that the lens is not a cluster member. Even though this particular event does not probe the distribution of planets in globular clusters, other potential cluster lens events can be verified using our methodology. Additionally, we find that microlens parallax measured using Optical Gravitational Lens Experiment (OGLE) photometry is consistent with the value found based on the light curve displacement between the Earth and Spitzer
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Evaluation of the environmental effects of stormwater pollutants for Oak Ridge National Laboratory
Despite Best Management Practices (BMP), total suspended solids (TSS) and oil and grease (O and G) concentrations in stormwater runoff frequently have been above the National Pollutant Discharge Elimination System (NPDES) Permit effluent limits at ORNL. Although the effects of stormwater pollutants to aquatic ecosystems are of concern regionally and nationally, NPDES permit violations at ORNL are best addressed on a site-specific basis. This document explores several key questions to determine whether the TSS and O and G noncompliances at ORNL are primarily a regulatory problem (i.e., Category 1 and 2 effluent limits are neither reasonably achievable nor effective in achieving environmental protection), or a legitimate ecological concern that will require effective remediation. The three tasks outlined in the study plan were to (1) clarify the degree of TSS and O and G noncompliances at ORNL, (2) provide guidance as to appropriate limits for TSS and O and G in Category 1 and 2 discharges, and (3) provide information about the effectiveness of possible mitigation or remediation measures for TSS and O and G in stormwater releases, assuming that such measures are needed for one or more ORNL Category 1 or 2 outfalls
INITIAL DATA RELEASE OF THEKEPLER-INT SURVEY
This paper describes the first data release of the Kepler-INT Survey (KIS),
that covers a 116 deg2 region of the Cygnus and Lyra constellations. The Kepler
field is the target of the most intensive search for transiting planets to
date. Despite the fact that the Kepler mission provides superior time series
photometry, with an enormous impact on all areas of stellar variability, its
field lacks optical photometry complete to the confusion limit of the Kepler
instrument necessary for selecting various classes of targets. For this reason,
we follow the observing strategy and data reduction method used in the IPHAS
and UVEX galactic plane surveys in order to produce a deep optical survey of
the Kepler field. This initial release concerns data taken between May and
August 2011, using the Isaac Newton Telescope on the island of La Palma. Four
broadband filters were used, U, g, r, i, as well as one narrowband one, Halpha,
reaching down to a 10-sigma limit of around 20th mag in the Vega system.
Observations covering around 50 deg2, thus about half of the field, passed our
quality control thresholds and constitute this first data release. We derive a
global photometric calibration by placing the KIS magnitudes as close as
possible to the Kepler Input Catalog (KIC) photometry. The initial data release
catalogue containing around 6 million sources from all the good photometric
fields is available for download from the KIS webpage, as well as via MAST.Comment: 10 pages, 7 figures - Accepted for publication in the Astronomical
Journa