130 citations · 1.1k across the 54 of their papers we have counts for
55 papers
TESS flares and chromospheric variability in the Pleiades, the Hyades, and Praesepe
A. Görgei, K. Vida, B. Seli +5
Magnetic activity is a result of the interaction between rotation and dynamo processes in cool stars with outer convection zones. Since open cluster members share a common age, dis…
CHARA Array Observations of the Evolved Components in Symbiotic Star Systems
Thomas Martin Gaudin, Ryan Norris, Magdalena Otulakowska-Hypka +30
The nature of the mechanisms that drive mass transfer in symbiotic stars remains an area of active research in stellar astronomy. Constraining the role that both stellar winds and…
CHIANTE I: Obliquity Measurements of Four High-Priority Ariel Targets in Binaries
Alex S. Polanski, Malena Rice, Catherine A. Clark +10
We present the first results from CHIANTE: a program using the EXtreme PREcision Spectrograph (EXPRES) at the Lowell Discovery Telescope to characterize potential targets of the Ar…
Empirical H- and K-band Limb Darkening for 31 CHARA Stars: A Near-Infrared Benchmark for Stellar-Atmosphere Models
Narsireddy Anugu, John D. Monnier, Antoine Mérand +9
Limb darkening, the decrease in stellar intensity from the disk center to the limb, encodes the temperature structure and opacity of stellar atmospheres. Direct spatially resolved…
Pre-nova Observations of T CrB: A view from the CHARA Array
Ryan Norris, Narsireddy Anugu, Thomas Gaudin +38
T CrB is a symbiotic recurrent nova consisting of a red giant and white dwarf with recent eruptions in 1866 and 1946 and an anticipated eruption in the mid 2020s. We report CHARA A…
Confirmation of Fe I on MASCARA-5 b's Dayside Observed With EXPRES
James T. Sikora, Joe Llama, Rachael M. Roettenbacher +5
MASCARA-5~b/TOI-1431~b is an ultra-hot Jupiter \citep[, , , $R_{\rm p}=…
Interferometric Images of the Starspot Evolution of Andromedae
Rachael M. Roettenbacher, John D. Monnier, Heidi Korhonen +21
The evolution of starspots of the giant primaries of RS CVn systems is typically detected indirectly with photometric and spectroscopic monitoring. These observations suggest slowl…
A Century of Radial Velocity and Astrometric Monitoring of 70 Oph AB: New PFS Data and Constraints on Planetary Companions
Yiting Li, Michael R. Meyer, Skylar D'Angiolillo +29
At a distance of 5.1 pc, the 70 Oph AB binary star system is one of the most favorable targets for future direct imaging and astrometry missions surveying mature, terrestrial plane…
The He I D3 Line as a Proxy for Magnetic Activity using EXPRES Solar Observations
Momo Ellwarth, Joe Llama, Lily L. Zhao +6
Stellar activity remains one of the primary challenges in the detection and characterization of low-mass exoplanets, as it can induce radial velocity (RV) variations that mask or m…
Orbital and Physical Properties of the Pleiades Binary 27 Tau (Atlas)
G. Torres, A. Tkachenko, K. Pavlovski +12
We report new spectroscopic and interferometric observations of the Pleiades binary star Atlas, which played an important role nearly three decades ago in settling the debate over…
Time-Evolution Images of the Hypergiant RW Cephei During the Re-brightening Phase Following the Great Dimming
Narsireddy Anugu, Douglas R. Gies, Rachael M. Roettenbacher +17
Stars with initial masses larger than 8 solar masses undergo substantial mass loss through mechanisms that remain elusive. Unraveling the origins of this mass loss is important for…
CHARA Near-Infrared Imaging of the Yellow Hypergiant Star Cassiopeiae: Convection Cells and Circumstellar Envelope
Narsireddy Anugu, Fabien Baron, John D. Monnier +18
Massive evolved stars such as red supergiants and hypergiants are potential progenitors of Type II supernovae, and they are known for ejecting substantial amounts of matter, up to…
Searching for stellar CMEs in the Praesepe and Pleiades clusters
K. Vida, B. Seli, R. M. Roettenbacher +4
On the Sun, the energetic, erupting phenomena of flares and coronal mass ejections (CMEs) often occur together. While space-based photometry has revealed frequent white-light flare…
The Orbit and Dynamical Mass of Polaris: Observations with the CHARA Array
Nancy Remage Evans, Gail Schaefer, Alexandre Gallenne +19
The 30 year orbit of the Cepheid Polaris has been followed with observations by the CHARA Array (Center for High Angular Resolution Astronomy) from 2016 through 2021. An additional…
The Orbit and Mass of the Cepheid AW Per
Nancy Remage Evans, Alexandre Gallenne, Pierre Kervella +17
The Cepheid AW Per is a component in a multiple system with a long period orbit. The radial velocities of Griffin (2016) cover the 38 year orbit well. An extensive program of inter…
The Extreme Stellar-Signals Project III. Combining Solar Data from HARPS, HARPS-N, EXPRES, and NEID
Lily L. Zhao, Xavier Dumusque, Eric B. Ford +37
We present an analysis of Sun-as-a-star observations from four different high-resolution, stabilized spectrographs -- HARPS, HARPS-N, EXPRES, and NEID. With simultaneous observatio…
Refining the Stellar Parameters of Ceti: a Pole-on Solar Analog
Maria Korolik, Rachael M. Roettenbacher, Debra A. Fischer +16
To accurately characterize the planets a star may be hosting, stellar parameters must first be well-determined. Ceti is a nearby solar analog and often a target for exoplanet s…
The Great Dimming of the hypergiant star RW Cephei: CHARA Array images and spectral analysis
N. Anugu, F. Baron, D. R. Gies +15
The cool hypergiant star RW Cephei is currently in a deep photometric minimum that began several years ago. This event bears a strong similarity to the Great Dimming of the red sup…
EXPRES IV: Two Additional Planets Orbiting Coronae Borealis Reveal Uncommon System Architecture
John M. Brewer, Lily L. Zhao, Debra A. Fischer +7
Thousands of exoplanet detections have been made over the last twenty-five years using Doppler observations, transit photometry, direct imaging, and astrometry. Each of these metho…
Measured Spin-Orbit Alignment of Ultra-Short Period Super-Earth 55 Cancri e
Lily L. Zhao, Vedad Kunovac, John M. Brewer +8
A planet's orbital alignment places important constraints on how a planet formed and consequently evolved. The dominant formation pathway of ultra-short period planets ( day)…
The EXPRES Stellar Signals Project II. State of the Field in Disentangling Photospheric Velocities
Lily L. Zhao, Debra A. Fischer, Eric B. Ford +40
Measured spectral shifts due to intrinsic stellar variability (e.g., pulsations, granulation) and activity (e.g., spots, plages) are the largest source of error for extreme precisi…
The Effect of Stellar Contamination on Low-resolution Transmission Spectroscopy: Needs Identified by NASA's Exoplanet Exploration Program Study Analysis Group 21
Benjamin V. Rackham, Néstor Espinoza, Svetlana V. Berdyugina +58
Study Analysis Group 21 (SAG21) of NASA's Exoplanet Exploration Program Analysis Group (ExoPAG) was organized to study the effect of stellar contamination on space-based transmissi…
EXPRES. III. Revealing the Stellar Activity Radial Velocity Signature of Eridani with Photometry and Interferometry
Rachael M. Roettenbacher, Samuel H. C. Cabot, Debra A. Fischer +20
The distortions of absorption line profiles caused by photospheric brightness variations on the surfaces of cool, main-sequence stars can mimic or overwhelm radial velocity (RV) sh…
Dynamical Surface Imaging of lambda Andromedae
Arturo O. Martinez, Fabien R. Baron, John D. Monnier +2
We present temperature maps of RS CVn star lambda Andromedae, reconstructed from interferometric data acquired in 2010 and 2011 by the MIRC instrument at the Center for High Angula…