Search Publications
Multiple Explanations for the Single Transit of KIC 5951458 Based on Radial Velocity Measurements Extracted with a Novel Matched-template Technique
Kane, Stephen R.; Howard, Andrew W.; Dalba, Paul A. +2 more
Planetary systems that show single-transit events are a critical pathway to increasing the yield of long-period exoplanets from transit surveys. From the primary Kepler mission, KIC 5951458 b (Kepler-456b) was thought to be a single-transit giant planet with an orbital period of 1310 days. However, radial velocity (RV) observations of KIC 5951458 …
Observations of Disintegrating Long-period Comet C/2019 Y4 (ATLAS): A Sibling of C/1844 Y1 (Great Comet)
Ye, Quan-Zhi; Hui, Man-To
We present a study of C/2019 Y4 (ATLAS) using Sloan gri observations from 2020 mid-January to early April. During this time span, the comet brightened with a growth in the effective cross-section of $\left(2.0\pm 0.1\right)\times {10}^{2}$ m2 s-1 from the beginning to ∼70 days preperihelion in late 2020 March, followed by a b…
An Analysis of the Statistics and Systematics of Limb Anomaly Detections in HST/STIS Transit Images of Europa
Strobel, Darrell; Saur, Joachim; Giono, Gabriel +5 more
Several recent studies derived the existence of plumes on Jupiter's moon Europa. The only technique that provided multiple detections is the far-ultraviolet imaging observations of Europa in transit of Jupiter taken by the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST). In this study, we reanalyze the three HST/STI…
Hubble Space Telescope Search for Activity in High-perihelion Objects
Mutchler, Max; Jewitt, David; Agarwal, Jessica +2 more
Solar system objects with perihelia beyond the orbit of Jupiter (q > 5 au) are too cold for water ice to generate an appreciable coma via sublimation. Despite this, numerous high-perihelion objects (HPOs) including many comets and recently escaped Kuiper Belt objects (Centaurs) are observed to be active out at least to the orbit of Saturn (q ∼ …
Beyond Gaia: Asteroseismic Distances of M Giants Using Ground-based Transient Surveys
Kochanek, C. S.; Huber, Daniel; Tonry, John +14 more
Evolved stars near the tip of the red giant branch show solar-like oscillations with periods spanning hours to months and amplitudes ranging from ∼1 mmag to ∼100 mmag. The systematic detection of the resulting photometric variations with ground-based telescopes would enable the application of asteroseismology to a much larger and more distant samp…
HD 150382: A Lithium-rich Star at the Early-AGB Stage?
Pereira, C. B.; Holanda, N.; Drake, N. A.
We report the discovery of a lithium-rich giant, HD 150382, a post-red-giant-branch clump star. The atmospheric parameters, the chemical abundances for 17 elements, and the isotopic ratio 12C/13C were determined using the equivalent width and the spectral synthesis methods. The lithium abundance was determined via spectral sy…
Upper Limits on Planet Occurrence around Ultracool Dwarfs with K2
Muirhead, Philip S.; Sagear, Sheila A.; Skinner, Julie N.
The occurrence of planets orbiting ultracool dwarfs is poorly constrained. We present results from a guest observer program on NASA's K2 spacecraft to search for transiting planets orbiting a sample of 827 ultracool dwarfs. Having found no transiting planets in our sample, we determined an upper limit on the occurrence of planets. We simulated pla…
Orbital Motion, Variability, and Masses in the T Tauri Triple System
Prato, L.; Schaefer, G. H.; Beck, Tracy L. +1 more
We present results from adaptive optics imaging of the T Tauri triple system obtained at the Keck and Gemini Observatories in 2015-2019. We fit the orbital motion of T Tau Sb relative to Sa and model the astrometric motion of their center of mass relative to T Tau N. Using the distance measured by Gaia, we derived dynamical masses of ${M}_{\mathrm…
Multiband Probabilistic Cataloging: A Joint Fitting Approach to Point-source Detection and Deblending
Finkbeiner, Douglas; Daylan, Tansu; Portillo, Stephen K. N. +1 more
Probabilistic cataloging (PCAT) outperforms traditional cataloging methods on single-band optical data in crowded fields. We extend our work to multiple bands, achieving greater sensitivity (∼0.4 mag) and greater speed (500×) compared to previous single-band results. We demonstrate the effectiveness of multiband PCAT on mock data, in terms of both…
First Images of the Protoplanetary Disk around PDS 201
Dong, Ruobing; Wagner, Kevin; Stone, Jordan +11 more
Scattered light imaging has revealed nearly a dozen circumstellar disks around young Herbig Ae/Be stars—enabling studies of structures in the upper disk layers as potential signs of ongoing planet formation. We present the first images of the disk around the variable Herbig Ae star PDS 201 (V* V351 Ori) and an analysis of the images and spectral e…