A5035332297- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Satellite Communication Systems
- Spacecraft Design and Technology
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Scientific Computing and Data Management
- Space Satellite Systems and Control
- Astro and Planetary Science
- History and Developments in Astronomy
- Space Science and Extraterrestrial Life
- Computational Physics and Python Applications
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Space exploration and regulation
- Adaptive optics and wavefront sensing
- Distributed and Parallel Computing Systems
- Economic and Technological Innovation
- Digital Radiography and Breast Imaging
- Magnetic and Electromagnetic Effects
- Big Data Technologies and Applications
- Innovative Microfluidic and Catalytic Techniques Innovation
University of Washington
2019-2024
Seattle University
2023
City University of Seattle
2019-2020
New Mexico State University
2011-2017
San Diego State University
2011
We present an improved method for determining the mass of neutron stars in eclipsing X-ray pulsar binaries and apply to six systems, namely Vela X-1, 4U 1538-52, SMC LMC X-4, Cen X-3, Her X-1. In previous studies determine star mass, eclipse duration has been approximated analytically by assuming companion is spherical with effective Roche lobe radius. use a numerical code based on geometry various optimizers analyze published data these which we supplement new spectroscopic photometric...
ABSTRACT Given the potential of ensemble asteroseismology for understanding fundamental properties large numbers stars, it is critical to determine accuracy scaling relations on which these measurements are based. From several powerful validation techniques, all indications so far show that stellar radius estimates from asteroseismic accurate within a few percent. Eclipsing binary systems hosting at least one star with detectable solar-like oscillations constitute ideal test objects...
Red-giant stars are an incredible source of information for testing models stellar evolution, as asteroseismology has opened up a window into their interiors. Such insights direct result the unprecedented data from space missions Kepler and CoRoT well recent theoretical advances. Eclipsing binaries also fundamental astrophysical objects, when coupled with asteroseismology, would provide two independent methods to obtain masses radii exciting opportunities develop highly constrained models....
Abstract We report studies on the mitigation of optical effects bright low-Earth-orbit (LEO) satellites Vera C. Rubin Observatory and its Legacy Survey Space Time (LSST). These include options for pointing telescope to avoid satellites, laboratory investigations trails LSST camera sensors, algorithms correcting image artifacts caused by trails, experiments darkening SpaceX Starlink ground-based follow-up observations. The original v0.9 are g ∼ 4.5 mag, initial experiment “DarkSat” is 6.1...
Large constellations of bright artificial satellites in low Earth orbit pose significant challenges to ground-based astronomy1. Current orbiting constellation have brightnesses between apparent magnitudes 4 and 6, whereas the near-infrared Ks band, they can reach magnitude 2 (ref. 2). Satellite operators, astronomers other users night sky are working on brightness mitigation strategies3,4. Radio emissions induce further potential risk radio telescopes that also need be evaluated. Here we...
Abstract In this Note, we discuss the rationale behind IAU CPS’s recommendation on satellite brightness for objects in low Earth orbit (LEO). Specifically, clarify reasoning chosen altitude dependence and limitations of choice. We further some approaches toward limits beyond LEO. This Note is intended both astronomers operators spirit furthering mutual cooperation.
In May 2019 SpaceX launched its first batch of 60 Starlink communication satellites, which surprised astronomers and laypeople with their appearance in the night sky. Astronomers have only now, a little over year later, accumulated enough observations constellation satellites like those being by OneWeb, run computer simulations likely impact when fully deployed, to thoroughly understand magnitude complexity problem. This research informed discussion at Satellite Constellations 1 (SATCON1)...
We combine Kepler photometry with ground-based spectra to present a comprehensive dynamical model of the double red giant eclipsing binary KIC 9246715. While two stars are very similar in mass (M1 = 2.171 [+0.006 / -0.008], M2 2.149 -0.008] Msun) and radius (R1 8.37 [+0.03 -0.07], R2 8.30 [+0.04 -0.03] Rsun), an asteroseismic analysis finds one main set solar-like oscillations unusually low-amplitude, wide modes. A second from other star may exist, but this marginal detection is extremely...
Abstract We investigate a novel satellite avoidance strategy to mitigate the impact of large commercial constellations in low-Earth orbit on Vera C. Rubin Observatory Legacy Survey Space and Time (LSST). simulate orbits currently planned Starlink OneWeb (∼40,000 satellites) test how effectively an upgraded scheduler algorithm can avoid them, assess overall survey is affected. Given reasonably accurate forecast, we find it possible adjust some satellites. Overall, sacrificing 10% LSST...
The Large Synoptic Survey Telescope (LSST) is an ambitious astronomical survey with a similarly Data Management component. for LSST includes processing on both nightly and yearly cadences to generate transient alerts, deep catalogs of the static sky, forced photometry light-curves billions objects at hundreds epochs, spanning least decade. algorithms running in these pipelines are individually sophisticated interact subtle ways. This paper provides overview those pipelines, focusing more...
Spectroscopic Eclipsing Binaries (SEBs) are fundamental benchmarks in stellar astrophysics and today observed breathtaking detail by missions like TESS, Kepler, APOGEE. We develop a methodology for simultaneous analysis of high precision Kepler light curves resolution near-IR spectra from APOGEE present orbital solutions evolutionary histories subset SEBs within this overlap. Radial velocities extracted using the Broadening Function technique combined with to yield binary solutions. The...
Abstract Large satellite constellations in low-Earth orbit seek to be the infrastructure for global broadband Internet and other telecommunication needs. We briefly review impacts of on astronomy show that service offered by these satellites will primarily target populations where it is unaffordable, not needed, or both. The harm done tens hundreds thousands astronomy, stargazers worldwide, environment acceptable.
We examine the simple model put forth in a recent note by Loeb 2024 regarding brightness of space debris size range 1-10 cm and their impact on Rubin Observatory LSST transient object searches. Their main conclusion was that "image contamination untracked might pose bigger challenge [than large commercial satellite constellations LEO]". Following corrections improvements to this model, we calculate apparent tumbling Low Earth Orbit (LEO) various sizes, briefly discuss likely potential...
SatHub is one of the four hubs IAU Centre for Protection Dark and Quiet Sky from Satellite Constellation Interference (CPS). It focuses on observations, data analysis, software, training materials to improve our understanding impact satellite constellations astronomy observers worldwide. As a preface more in-depth IAUS385 sessions, we gave summary some recent work by members current status constellations, including optical radio observations. We shared how audience can join or get involved,...
Abstract We examine the simple model put forth in a recent note by Loeb regarding brightness of space debris size range 1–10 cm and their impact on Rubin Observatory Legacy Survey Space Time (LSST) transient object searches. Their main conclusion was that “image contamination untracked might pose bigger challenge [than large commercial satellite constellations Low-Earth orbit].” Following corrections improvements to this model, we calculate apparent tumbling low-Earth orbit (LEO) various...
This Birds-of-a-Feather (BOF) session on 6 November 2023 was organized by leaders and members of SatHub at the International Astronomical Union Centre for Protection Dark Quiet Sky from Satellite Constellation Interference (IAU CPS). is dedicated to observations, data analysis, software, related activities. The opened with a talk current state affairs regards satellite constellation mitigation, focus optical astronomy, moved focused discussion around top-voted topics. These included tools...
Satellite constellation interference occurs across astronomical disciplines. We present examples of from radio and $\gamma$-Ray astronomy to optical spectroscopic in ground-based space-borne facilities. In particular, we discuss the impact artificial satellites on Hubble Space Telescope (HST), High Energy Stereoscopic System (H.E.S.S.), an Imaging Atmospheric Cherenkov Telescope, as well possible mitigation strategies for European Southern Observatory 4-metre Multi-Object Spectrograph (ESO...
The IAU Centre for the Protection of Dark and Quiet Sky from Satellite Constellation Interference (CPS), established in early 2022 co-hosted by NSF's NOIRLab SKA Observatory, was created to unify efforts work towards mitigating some effects satellite constellations on astronomy. SatHub, one four sub-groups CPS, focuses software related tools aid observers industry partners addressing issues caused commercial constellations.
The growing number of satellite constellations in low Earth orbit (LEO) enhances global communications and observation, support space commerce is a high priority many governments. At the same time, proliferation satellites LEO has negative effects on astronomical observations research, preservation dark quiet sky. These reflect sunlight onto optical telescopes, their radio emission impacts observatories, jeopardising our access to essential scientific discoveries through astronomy. changing...