Search Publications
Observations of the Ultraviolet-bright Star ZNG 1 in the Globular Cluster M5 (NGC 5904)
Dixon, William V.
We have analyzed archival spectra of the hot UV-bright star ZNG 1 in the globular cluster M5 (NGC 5904) obtained with the Far Ultraviolet Spectroscopic Explorer and the Space Telescope Imaging Spectrograph. From these data, we derive an effective temperature T eff = 43,000 ± 1400 K, a surface gravity $\mathrm{log}g$ = 4.47 ± 0.08, a rot…
Ages of "Singles" versus "Multis": Predictions for Dynamical Sculpting over Gyr in the Kepler Sample
Ballard, Sarah; Lam, Christopher
The sample of host stars with multiple transiting planets has illuminated the orbital architectures of exoplanetary systems. These architectures may be shaped mostly by formation conditions, be continually sculpted by ongoing dynamical processes, or both. As more studies have placed planet occurrence within a galactic context, evidence has emerged…
Characterization of the Blue Straggler Star Populations, through Statistical, Photometric, and Spectral Energy Distribution Analysis, in the Old Open Cluster: NGC 2243
Medhi, Biman J.; Sheikh, A. H.
We present a statistical, photometric, and spectral energy distribution (SED) analysis of the poorly studied old open cluster: NGC 2243, to characterize its blue straggler star (BSS) population. We applied ensemble-based unsupervised machine learning methods to estimate the membership probabilities using Gaia Data Release 3 (DR3) astrometric data.…
Variations in the Radius Distribution of Single- and Compact Multiple-transiting Planets
Dittmann, Jason A.; Ballard, Sarah; Liberles, Benjamin T. +1 more
Previous work has established the enhanced occurrence of compact systems of multiple small exoplanets around metal-poor stars. Understanding the origin of this effect in the planet formation process is a topic of ongoing research. Here we consider the radii of planets residing in systems of multiple transiting planets, compared to those residing i…
Asteroseismological Analysis of the Non-Blazhko RRab Star EPIC 248846335 in the LAMOST–Kepler/K2 Project
Liu, Gao-Chao; Zong, Weikai; Fu, Jian-Ning +9 more
We conduct an asteroseismological analysis on the non-Blazhko ab-type RR Lyrae star EPIC 248846335, employing the Radial Stellar Pulsations module of the Modules for Experiments in Stellar Astrophysics based on the set of stellar parameters. The atmospheric parameters T eff = 6933 ± 70 K, log g = 3.35 ± 0.50, and [Fe/H] = ‑1.18 ± 0.14 a…
The Components of Cepheid Systems: The FN Vel System
Mérand, Antoine; Evans, Nancy Remage; Anderson, Richard I. +8 more
Cepheid masses continue to be important tests of evolutionary tracks for intermediate-mass stars as well as important predictors of their future fate. For systems where the secondary is a B star, Hubble Space Telescope ultraviolet spectra have been obtained. From these spectra a temperature can be derived, and from this a mass of the companion M <…
Walking the Line: Young Stars on the Boundary of the Epsilon Cha and Lower Centaurus Crux Associations
Kastner, Joel H.; Dickson-Vandervelde, D. Annie; Varga, Attila +1 more
Gaia Data Release 3 (DR3) has provided the largest and most astrometrically precise catalog of nearby stars to date, allowing for a more complete membership census of nearby, young stellar moving groups. These loose associations of young (age <100 Myr) stars within ∼100 pc are vital laboratories for the study of the early evolution of low-mass …
A Near-infrared Survey of Candidate Haumea Family Members
Fraser, Wesley C.; Pike, Rosemary E.; Ragozzine, Darin +5 more
The Haumea family is the only known dynamical family in the trans-Neptunian region. To date, 10 family members have been unambiguously identified using near-infrared (NIR) spectral or photometric data in combination with their strong dynamical proximity and the rest of the family. In this work, we build off previous empirically constructed models …
Analysis of KIC 7023917: Spotted Low-mass Ratio Eclipsing Binary with δ Scuti Pulsations
Skarka, Marek; Karjalainen, Raine; Gajdoš, Pavol +3 more
Times of minima of eclipsing binary KIC 7023917 show quasiperiodic anti-symmetric deviations from the calculated one with an amplitude of up to 10 minutes and a period of 200–300 days. These changes correlate with the observed variations of the light-curve maxima (amplitude and phase separation). We used photometric data obtained by Kepler and TES…
DECam Multimessenger Astrophysics Pipeline. I. From Raw Data to Single-exposure Candidates
Matheson, Thomas; Meisner, Aaron; Fu, Shenming +3 more
We introduce a pipeline that performs rapid image subtraction and source selection to detect transients, with a focus on identifying gravitational-wave optical counterparts using the Dark Energy Camera (DECam). In this work, we present the pipeline steps from processing raw data to identification of astrophysical transients on individual exposures…