A5055528928- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Geophysics and Gravity Measurements
- History and Developments in Astronomy
- Insect and Arachnid Ecology and Behavior
- Distributed and Parallel Computing Systems
- Dark Matter and Cosmic Phenomena
- Educational Strategies and Epistemologies
- Visual and Cognitive Learning Processes
- Paranormal Experiences and Beliefs
- Inertial Sensor and Navigation
- Astrophysical Phenomena and Observations
- Science Education and Pedagogy
- Solar and Space Plasma Dynamics
- Galaxies: Formation, Evolution, Phenomena
- Historical Astronomy and Related Studies
City University of New York
2020-2024
The Graduate Center, CUNY
2020-2024
American Museum of Natural History
2020-2024
Hunter College
2021-2024
Abstract A complete accounting of nearby objects—from the highest-mass white dwarf progenitors down to low-mass brown dwarfs—is now possible, thanks an almost set trigonometric parallax determinations from Gaia, ground-based surveys, and Spitzer follow-up. We create a census objects within Sun-centered sphere 20 pc radius check published literature decompose each binary or higher-order system into its separate components. The result is volume-limited ∼3600 individual star formation products...
Abstract In this work we examine M dwarf rotation rates at a range of ages to establish benchmarks for gyrochronology. This includes sample 713 spectroscopically classified M0–M8 dwarfs with new measured from K2 light curves. We analyze data and recover 179 these objects. add members clusters known (5–700 Myr), as well objects assumed have field (≳1 Gyr). use Gaia DR2 parallax <?CDATA $(G\mbox{--}{G}_{\mathrm{RP}})$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Abstract We propose that 14 co-moving groups of stars uncovered by Kounkel & Covey may be related to known nearby moving and bridge those open clusters with similar ages space velocities. This indicates spatially much more extended than previously thought, some them might parts tidal tails around the cores clusters, reminiscent recently found Hyades a handful other clusters. For example, we find both Carina Columba associations linked Theia 208 from together form large tail Platais 8...
Abstract We report the identification of 89 new systems containing ultracool dwarf companions to main-sequence stars and white dwarfs, using citizen science project Backyard Worlds: Planet 9 cross-reference between Gaia CatWISE2020. 32 these 33 host were followed up with spectroscopic observations, companion spectral types ranging from M7–T9 G2–M9. These exhibit diverse characteristics, young old ages, blue very red morphologies, potential membership known moving groups, evidence binarity in...
Undergraduate physics and astronomy students are expected to engage with scientific literature as they begin their research careers, yet reading comprehension skills rarely explicitly taught in major courses. We seek determine the efficacy of a assignment designed improve undergraduate (or related) majors’ perceived ability by using accessible summaries current written experts field. During 2022–2023 academic year, faculty members from six institutions incorporated assignments Astrobites...
We report the discovery of Oceanus moving group, a $\approx$ 500 Myr-old group with 50 members and candidate at distances 2-50 pc from Sun using an unsupervised clustering analysis nearby stars Gaia DR3 data. This new includes nearest brown dwarf WISE J104915.57-531906.1 AB (Luhman 16 AB) distance 2 pc, which was previously suspected to be young (600-800 Myr) based on comparison its dynamical mass measurements evolutionary models. use empirical color-magnitude sequences, stellar activity...
Through the Backyard Worlds: Planet 9 citizen science project we discovered a late-type L dwarf co-moving with young K0 star BD+60 1417 at projected separation of 37" or 1662 AU. The secondary - CWISER J124332.12+600126.2 (W1243) is detected in both CatWISE2020 and 2MASS reject tables. photometric distance CatWISE proper motion match that primary within ~1sigma our estimates for chance alignment yield zero probability. Follow-up near infrared spectroscopy reveals W1243 to be very red...
Abstract The Tucana–Horologium association (Tuc-Hor) is a 40 Myr old moving group in the southern sky. In this work, we measure rotation periods of 313 Tuc-Hor objects with TESS light curves derived from full-frame images and membership lists driven by Gaia EDR3 kinematics known youth indicators. We recover period for 81.4% sample report 255 objects. From these identify 11 candidate binaries based on multiple periodic signals or outlier DR2 renormalized unit weight error values. also three...
Through the Backyard Worlds: Planet 9 citizen science project, we have identified a wide-separation ($\sim$10', $\sim$9900 au projected) substellar companion to nearby ($\sim$17.5 pc), mid-M dwarf Ross 19. We developed new formalism for determining chance alignment probabilities based on BANYAN $\Sigma$ tool, and find 100% probability that this is physically associated pair. detailed examination of 19A, system metal-poor ([Fe/H]=$-$0.40$\pm$0.12) with an age 7.2$^{+3.8}_{-3.6}$ Gyr....
Abstract We present the discovery of 13 new widely separated T dwarf companions to M primaries, identified using Wide-field Infrared Survey Explorer/NEOWISE data by CatWISE and Backyard Worlds: Planet 9 projects (hereafter BYW). This sample represents an ∼60% increase in number known + systems, allows us probe most extreme products binary/planetary system formation, a space made available CatWISE2020 catalog BYW effort. Highlights among are WISEP J075108.79-763449.6, previously T9 thought be...
Abstract Measuring fundamental stellar parameters is key to fully comprehending the evolution of stars. However, current theoretical models overpredict effective temperatures, and underpredict radii, compared observations K M dwarfs (radius inflation problem). In this work, we have developed a model-independent method infer precise radii single FGK using Gaia DR3 parallaxes photometry, used it study radius problem. We calibrated nine surface brightness–color relations for three magnitudes...
Abstract We present a set of over-densities in spatial-kinematic space previously identified by Kounkel & Covey (2019) that may constitute extended tidal tails associated with the nearby, 400 Myr old Ursa Major association. This sample 1599 stars has main-sequence turnoff point consistent age Major, and might contain its missing low-mass members. It includes four candidate white dwarfs properties seem total about Myr, but we estimate from older dwarf interlopers 33% be contaminated...
We present the discovery of CWISE J151044.74$-$524923.5, a wide low-mass companion to nearby ($\sim$24.7 pc) system L 262-74, which was identified through Backyard Worlds: Planet 9 citizen science project. detail properties system, and we assess that this is mid-L dwarf, will need be verified spectroscopically. With an angular separation 74\farcs3, estimate projected physical $\sim$1837 au from central system.
Measuring fundamental stellar parameters is key to fully comprehending the evolution of stars. However, current theoretical models over-predict effective temperatures, and under-predict radii, compared observations K M dwarfs (radius inflation problem). In this work, we developed a model independent method infer precise radii single FGK using Gaia DR3 parallaxes photometry, used it study radius problem. We calibrated nine surface brightness-color relations for three magnitudes colors sample...
Abstract Recently Gagné et al. suggested that young moving groups with similar kinematic properties could be part of larger dissolving structures. One example was IC 2602 as the core a group associations, including its corona (CIC 2602), Tucana-Horologium (THA), and parts Theia 92. We explore this hypothesis by measuring rotation periods 953 objects selected using Gaia DR3 kinematics from 2602, CIC 92, newly identified stars bridge THA. use Transiting Exoplanet Survey Satellite (TESS) full...
We report the identification of 89 new systems containing ultracool dwarf companions to main sequence stars and white dwarfs, using citizen science project Backyard Worlds: Planet 9 cross-reference between Gaia CatWISE2020. Thirty-two these thirty-three host were followed up with spectroscopic observations, companion spectral types ranging from M7-T9 G2-M9. These exhibit diverse characteristics, young old ages, blue very red morphologies, potential membership known moving groups, evidence...
We present the discovery of 13 new widely separated T dwarf companions to M primaries, identified using WISE/NEOWISE data by CatWISE and Backyard Worlds: Planet 9 projects. This sample represents a $\sim$60% increase in number known M+T systems, allows us probe most extreme products binary/planetary system formation, space made available CatWISE2020 catalog effort. Highlights among are WISEP J075108.79-763449.6, previously T9 thought be old due its SED, which we now find is part...
Abstract We present the spectroscopy of CWISE J151044.74−524923.5, a wide low-mass companion to nearby (~24.7 pc) L 262-74 system. Analyzing near-infrared spectrum obtained with TripleSpec4 spectrograph on Southern Astrophysical Research Telescope, we confirm that it is brown dwarf unusually red colors. Although this redness can be characteristic young, low-gravity dwarfs, assess object likely field being reddened by factors other than youth. assign spectral type L6 (pec). Finally, highlight...
A complete accounting of nearby objects -- from the highest-mass white dwarf progenitors down to low-mass brown dwarfs is now possible, thanks an almost set trigonometric parallax determinations Gaia, ground-based surveys, and Spitzer follow-up. We create a census within Sun-centered sphere 20-pc radius check published literature decompose each binary or higher-order system into its separate components. The result volume-limited $\sim$3,600 individual star formation products useful in...
The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) dataset will dramatically alter our understanding the Universe, from origins Solar System to nature dark matter energy. Much this research depend on existence robust, tested, scalable algorithms, software, services. Identifying developing such tools ahead time has potential significantly accelerate delivery early science LSST. Developing these collaboratively, making them broadly available, can enable more inclusive...
Abstract As an open cluster orbits the Milky Way, gravitational fields distort it, stripping stars from core and forming tidal tails. Recent work has identified tails of Praesepe cluster; we explore rotation periods as a way to confirm these candidate members. In clusters, period distribution evolves over time due magnetic braking. Since tidally stripped originally formed within cluster, they should follow same in core. We analyze 96 members observed by NASA’s Transiting Exoplanet Survey...
Humans like to party, and New Year celebrations are a great way do that. However Years that rely on an orbital year don't line up with those use Lunar Calendar, as there currently 12.368 synodic months (moonths) in year. There is cyclostratigraphic, paleontological, tidal rhythmite data reveal over billions of years the interplay angular momentum between Sun, Earth Moon has changed rate rotation Earth, at same time evolved orbit Moon, therefore length month. Using subset this referencing...
Undergraduate physics and astronomy students are expected to engage with scientific literature as they begin their research careers, but reading comprehension skills rarely explicitly taught in major courses. We seek determine the efficacy of lesson plans designed improve undergraduate (or related) majors' perceived ability by using accessible summaries current written experts field. During 2022-2023 academic year, twelve faculty members incorporated from Astrobites into courses, surveyed...