The Measured Impact of Chromatic Atmospheric Effects on Barycentric Corrections: Results from the EXtreme PREcision Spectrograph
| Autor: | J. M. Joel Ong, Debra A. Fischer, Ryan T. Blackman |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010504 meteorology & atmospheric sciences
FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics 01 natural sciences Astronomical spectroscopy Standard deviation 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Chromatic scale Instrumentation and Methods for Astrophysics (astro-ph.IM) 010303 astronomy & astrophysics Spectrograph Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Earth and Planetary Astrophysics (astro-ph.EP) Physics Astronomy and Astrophysics Exoplanet Radial velocity Stars Wavelength 13. Climate action Space and Planetary Science Astrophysics::Earth and Planetary Astrophysics Astrophysics - Instrumentation and Methods for Astrophysics Astrophysics - Earth and Planetary Astrophysics |
| Zdroj: | The Astronomical Journal. 158:40 |
| ISSN: | 1538-3881 |
| Popis: | One source of error in high-precision radial velocity measurements of exoplanet host stars is chromatic change in Earth's atmospheric transmission during observations. Mitigation of this error requires that the photon-weighted barycentric correction be applied as a function of wavelength across the stellar spectrum. We have designed a system for chromatic photon-weighted barycentric corrections with the EXtreme PREcision Spectrograph (EXPRES) and present results from the first year of operations, based on radial velocity measurements of more than $10^3$ high-resolution stellar spectra. For observation times longer than 250 seconds, we find that if the chromatic component of the barycentric corrections is ignored, a range of radial velocity errors up to 1 m s$^{-1}$ can be incurred with cross-correlation, depending on the nightly atmospheric conditions. For this distribution of errors, the standard deviation is 8.4 cm s$^{-1}$ for G-type stars, 8.5 cm s$^{-1}$ for K-type stars, and 2.1 cm s$^{-1}$ for M-type stars. This error is reduced to well-below the instrumental and photon-noise limited floor by frequent flux sampling of the observed star with a low-resolution exposure meter spectrograph. 11 pages, 7 figures, accepted to AJ |
| Databáze: | OpenAIRE |
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