Search Publications
The Return of the Rosetta Target: Keck Near-infrared Observations of Comet 67P/Churyumov-Gerasimenko in 2021
Ootsubo, Takafumi; Villanueva, Geronimo L.; Cochran, Anita L. +20 more
High-resolution near-infrared ground-based spectroscopic observations of comet 67P/Churyumov-Gerasimenko near its maximum activity in 2021 were conducted from the W. M. Keck Observatory, using the facility spectrograph NIRSPEC. 67P is the best-studied comet to date because of the unprecedented detail and insights provided by the Rosetta mission du…
Direct Imaging Explorations for Companions around Mid-Late M Stars from the Subaru/IRD Strategic Program
Henning, Thomas; Nakagawa, Takao; Currie, Thayne +32 more
The Subaru telescope is currently performing a strategic program (SSP) using the high-precision near-infrared (NIR) spectrometer IRD to search for exoplanets around nearby mid/late M dwarfs via radial velocity (RV) monitoring. As part of the observing strategy for the exoplanet survey, signatures of massive companions such as RV trends are used to…
Variable Blue Straggler Stars in the Open Cluster NGC 6819 Observed in the Kepler "Superstamp" Field
Guzik, Joyce A.; Németh, Péter; Baran, Andrzej S. +4 more
NGC 6819 is an open cluster of age 2.4 Gyr that was in the NASA Kepler spacecraft's field of view from 2009 to 2013. The central part of the cluster was observed in a 200 × 200 pixel "superstamp" during these four years in 30 minute cadence photometry, providing a unique, high-precision, long time-series data set. The cluster contains "blue stragg…
Variability in NGC 3201 Giant Stars
Villanova, S.; Parisi, C.; Cortés, C. C. +2 more
We present the analysis of 510 light curves in V and I bands of 255 giant stars in the globular cluster NGC 3201. Our aim is to expand the sample of new types of variables reported in a previous study. These variables show a short period (P V < 0.6 day) and a low amplitude (A(V) < 0.06 mag.). We first searched for variability us…
Comet 108P/Ciffreo: The Blob
Mutchler, Max; Jewitt, David; Li, Jing +2 more
Short-period comet 108P/Ciffreo is known for its peculiar double morphology, in which the nucleus is accompanied by a comoving, detached, diffuse "blob." We report new observations of 108P/Ciffreo taken with the Hubble Space Telescope and the Nordic Optical Telescope and use them to determine the cause of this unusual morphology. The separation an…
Detecting Long-period Variability in the SDSS Stripe 82 Standards Catalog
Ivezić, Željko; Ilić, Dragana; Kovačević, Andjelka B. +5 more
We report the results of a search for long-period (100 < P < 600 days) periodic variability in the SDSS Stripe 82 standards catalog. The SDSS coverage of Stripe 82 enables such a search because there are on average 20 observations per band in ugriz bands for about one million sources, collected over about 6 yr, with a faint limit of r ~ 22 m…
The Environments around W Serpentis Systems: Independent Limits on System Masses and Extended Envelopes
Davidge, T. J.
Information extracted from the Gaia Data Release 3 is used to examine the stellar contents within projected separations of 10 pc from eight close binary systems that are either classical W Serpentis systems or related objects. The goal is to search for remnant star clusters or moving groups with proper motions that are similar to those of the bina…
Precise Distance Measurement for a Near-Earth Asteroid by the Refined Rotational Reflex Velocity Method
Lin, F. R.; Peng, Q. Y.; Guo, B. F. +1 more
The rotational reflex velocity (RRV) method was proposed by Heinze and Metchev in 2015 and was used to measure the distances of main-belt asteroids (MBAs). Later, Lin et al. generalized this method using spherical astronomy in 2016. The method measures the distances of MBAs using the observations from a single ground-based telescope over two night…
PCAT-DE: Reconstructing Pointlike and Diffuse Signals in Astronomical Images Using Spatial and Spectral Information
Daylan, Tansu; Zemcov, Michael; Sayers, Jack +5 more
Observational data from astronomical imaging surveys contain information about a variety of source populations and environments, and their complexity will increase substantially as telescopes become more sensitive. Even for existing observations, measuring the correlations between pointlike and diffuse emission can be crucial to correctly inferrin…
A Search for Gas-Rich Dwarf Galaxies in the Local Universe with ALFALFA and the WIYN One Degree Imager
Cannon, John M.; Salzer, John J.; Haynes, Martha P. +5 more
We present results from an optical search for Local Group dwarf galaxy candidates associated with the Ultra-Compact High Velocity Clouds (UCHVCs) discovered by the ALFALFA neutral hydrogen survey. The ALFALFA UCHVCs are isolated, compact H I clouds with projected sizes, velocities, and estimated H I masses that suggest they may be nearby dwarf gal…