Search Publications
Establishing Baselines for Six Short-period δ Scuti Variables
Stephens, Denise C.; Hintz, Eric G.; Suggs, Christiana Z.
As part of our variable star follow-up program, we have examined a number of stars from the Asteroid Terrestrial-impact Last Alert System (ATLAS) survey. Using a combination of our own data, ATLAS data, and other archival data, we confirmed the published periods and established a baseline ephemeris for each star. This initial sample of six stars a…
The TESS-Keck Survey. XXII. A Sub-Neptune Orbiting TOI-1437
Barclay, Thomas; Batalha, Natalie M.; Mayo, Andrew W. +40 more
Exoplanet discoveries have revealed a dramatic diversity of planet sizes across a vast array of orbital architectures. Sub-Neptunes are of particular interest; due to their absence in our own solar system, we rely on demographics of exoplanets to better understand their bulk composition and formation scenarios. Here, we present the discovery and c…
Theia 456: Tidally Shredding an Open Cluster
Cargile, Phillip A.; Agüeros, Marcel A.; Curtis, Jason L. +4 more
The application of clustering algorithms to the Gaia astrometric catalog has revolutionized our census of stellar populations in the milky Way, including the discovery of many new dispersed structures. We focus on one such structure, Theia 456 (COIN-Gaia-13), a loosely bound collection of ∼320 stars spanning ∼120 pc that has previously been shown …
Modeling the Wavelength Dependence of Pixel Response Nonuniformity of a CCD Sensor
Meng, Xianmin; Du, Wei; Zhan, Hu +2 more
Precision measurements in astronomy require stringent control of systematics such as those arising from imperfect correction of sensor effects. In this work, we develop a parametric method to model the wavelength dependence of pixel response nonuniformity (PRNU) for a laser-annealed backside-illuminated charge-coupled device. The model accurately …
Joint Deconvolution of Astronomical Images in the Presence of Poisson Noise
van Dyk, David A.; Kashyap, Vinay L.; Siemiginowska, Aneta +2 more
We present a new framework for joint likelihood deconvolution (Jolideco) of a set of astronomical observations of the same sky region in the presence of Poisson noise. The observations may be obtained from different instruments with different resolution, and different point-spread functions (PSFs). Jolideco reconstructs a single flux image by opti…
Li Evolution among Stars of Low/Intermediate Mass: the Metal-deficient Open Cluster NGC 2204
Twarog, Bruce A.; Anthony-Twarog, Barbara J.; Deliyannis, Constantine P. +2 more
We have analyzed high-dispersion spectra in the Li 6708 Å region for 167 stars within the anticenter cluster NGC 2204. From 105 probable members, abundance analysis of 45 evolved stars produces [Fe/H] = ‑0.40 ± 0.12, [Si/Fe] = 0.14 ± 0.12, [Ca/Fe] = 0.29 ± 0.07, and [Ni/Fe] = ‑0.12 ± 0.10, where quoted errors are standard deviations. With E(B ‑ V)…
Fluorine Abundances in Local Stellar Populations
Grisoni, V.; Brady, K. E.; Pilachowski, C. A. +2 more
We present the first fluorine measurements in 12 normal K giants belonging to the Galactic thin and thick disks using spectra obtained with the Phoenix infrared spectrometer on the 2.1 m telescope at Kitt Peak. Abundances are determined from the (1‑0) R9 2.3358 µm feature of the molecule HF. Additionally, sodium abundances are derived in 25 …
Orbit of the Patroclus–Menoetius Binary System and Predictions for the 2024/2025 Mutual Events Season
Popescu, Marcel; Licandro, Javier; Berthier, Jérôme +5 more
We report on the ephemeris development for Menoetius, the satellite of Patroclus. Our data set consisted of ground–based and Hubble Space Telescope relative astrometry, as well as 42 lightcurves from the mutual events seasons in 2007, 2012, and 2017/2018. Our dynamical model included the effects of oblate, nonspherical shapes of the components, an…
Revised Architecture and Two New Super-Earths in the HD 134606 Planetary System
Butler, R. Paul; Kane, Stephen R.; Wittenmyer, Robert A. +16 more
Multiplanet systems exhibit a diversity of architectures that diverge from the solar system and contribute to the topic of exoplanet demographics. Radial velocity (RV) surveys form a crucial component of exoplanet surveys, as their long observational baselines allow for searches for more distant planetary orbits. This work provides a significantly…
SMC-Last Extracted Photometry
Boyer, M. L.; Oliveira, Joana M.; van Loon, Jacco Th. +11 more
We present point-source photometry from the Spitzer Space Telescope's final survey of the Small Magellanic Cloud (SMC). We mapped nearly 30 deg2 in two epochs in 2017, with the second extending to early 2018 at 3.6 and 4.5 µm using the Infrared Array Camera. This survey duplicates the footprint from the SAGE-SMC program in 2008. T…