5 papers
gr8stars II : judgement day for spectroscopic parameter model systematics
Alix Violet Freckelton, Annelies Mortier, Megan Bedell +18
Many areas of astrophysics, including exoplanetary studies, rely on precise and accurate stellar parameters. This demands that uncertainties on these parameters truly reflect all b…
Uncovering Hidden Systematics in Extreme-Precision Radial Velocity Measurements
Lily L. Zhao, Debra A. Fischer, Andrew E. Szymkowiak +2
We identify and correct for small but coherent instrumental drifts in seven years of radial velocity data from the EXtreme PREcision Spectrograph (EXPRES). The systematics are most…
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…
The Effects of Sunspots on Spectral Line Shapes in the Visible
Claire Komori, John M. Brewer, Lily L. Zhao
We present a comparative spectral analysis to explore the ability of a cooler Sun model to accurately capture the spectral line shape changes caused by Sunspots. In the search for…
Planet Masses, Radii, and Orbits from NASA's K2 Mission
Andrew W. Howard, Evan Sinukoff, Sarah Blunt +50
We report the masses, sizes, and orbital properties of 86 planets orbiting 55 stars observed by NASA's K2 Mission with follow-up Doppler measurements by the HIRES spectrometer at t…