Search Publications
A Mass-Magnitude Relation for Low-mass Stars Based on Dynamical Measurements of Thousands of Binary Star Systems
Blake, Cullen H.; Giovinazzi, Mark R.
Stellar mass is a fundamental parameter that is key to our understanding of stellar formation and evolution, as well as the characterization of nearby exoplanet companions. Historically, stellar masses have been derived from long-term observations of visual or spectroscopic binary star systems. While advances in high-resolution imaging have enable…
Magnetic Activity on Four Short-period Contact Binaries: V0576 Peg, KW Psc, V0873 Per, and FY Boo
Wang, Shuang; Yang, Yuangui; Yuan, Huiyu +1 more
We presented new photometry for four short-period late-type binaries, observed by three small telescopes in China from 2020 September to 2021 December. Seven sets of light curves (including the TESS data for FY Boo) were analyzed by using the W-D method. Three binaries (V0576 Peg, V0873 Per, and FY Boo) are W-type binaries with q ≃ 2.5, while KW P…
Activity and Rotation of Nearby Field M Dwarfs in the TESS Southern Continuous Viewing Zone
Rampalli, Rayna; Mann, Andrew W.; Agüeros, Marcel A. +8 more
The evolution of magnetism in late-type dwarfs remains murky, as we can only weakly predict levels of activity for M dwarfs of a given mass and age. We report results from our spectroscopic survey of M dwarfs in the Southern Continuous Viewing Zone (CVZ) of the Transiting Exoplanet Survey Satellite (TESS). As the TESS CVZs overlap with those of th…
Nine Bright γ Doradus Variables Discovered with Ground-based Photometry
Henry, Gregory W.; Williamson, Michael H.; Fekel, Francis C.
We have used precise photometric and high-dispersion spectroscopic observations to study nine candidate γ Doradus (γ Dor) stars, identified as optically variable comparison stars in our photometric studies of Sun-like stars. In this paper, we confirm these nine candidates as new γ Dor variables. All exhibit sinusoidal variability with amplitudes b…
Discovery of 16 New Members of the Solar Neighborhood Using Proper Motions from CatWISE2020
Meisner, Aaron M.; Kirkpatrick, J. Davy; Schneider, Adam C. +15 more
In an effort to identify nearby and unusual cold objects in the solar neighborhood, we searched for previously unidentified moving objects using CatWISE2020 proper motion data combined with machine learning methods. We paired the motion candidates with their counterparts in 2MASS, UHS, and VHS. Then we searched for white dwarf, brown dwarf, and su…
An Adaptive Optics Census of Companions to Northern Stars Within 25 pc with Robo-AO
Baranec, Christoph; Law, Nicholas M.; Riddle, Reed +8 more
In order to assess the multiplicity statistics of stars across spectral types and populations in a volume-limited sample, we censused nearby stars for companions with Robo-AO. We report on observations of 1157 stars of all spectral types within 25 pc with decl. >-13° searching for tight companions. We detected 154 companion candidates with sepa…
How Do Spitzer IRAC Fluxes Compare to HST CALSPEC?
Gordon, Karl D.; Hubeny, Ivan; Bohlin, Ralph C. +1 more
An accurate tabulation of stellar brightness in physical units is essential for a multitude of scientific endeavors. The HST/CALSPEC database of flux standards contains many stars with spectral coverage in the 0.115-1 µm range, with some extensions to longer wavelengths of 1.7 or 2.5 µm. Modeled flux distributions to 32 µm for ca…
Constructing the Milky Way Stellar Halo in the Galactic Center by Direct Orbit Integration
Yang, Chengqun; Liu, Chao; Xue, Xiang-Xiang +2 more
The halo stars on highly-radial orbits should inevitably pass the center regions of the Milky Way. Under the assumption that the stellar halo is in "dynamical equilibrium" and is axisymmetric, we integrate the orbits of ~10,000 halo K giants at 5 ≤ r ≤ 50 kpc cross-matched from LAMOST DR5 and Gaia DR3. By carefully considering the selection functi…
TESS Observations of Kepler Systems with Transit Timing Variations
Dalba, Paul A.; Livingston, John H.; Jontof-Hutter, Daniel
We identify targets in the Kepler field that may be characterized by transit timing variations and are detectable by the Transiting Exoplanet Survey Satellite (TESS). Despite the reduced signal-to-noise ratio of TESS transits compared to Kepler, we recover 48 transits from 13 systems in Sectors 14, 15, 26, 40 and 41. We find strong evidence of a n…
Mapping out the Stellar Populations of IC 2602 and IC 2391
Henry, Todd J.; James, Hodari-Sadiki; Jao, Wei-Chun +4 more
IC 2391 and IC 2602 are important benchmarks for testing early star and planet evolution theories, both structural and dynamical, because they are the nearest open clusters with ages of ~50 Myr. We refine membership lists for these clusters by identifying candidate members using Gaia DR2 kinematic and distance information. We identify 451 candidat…