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Author Davis, Allen B. ♦ Fischer, Debra A. ♦ Cisewski, Jessi ♦ Dumusque, Xavier ♦ Ford, Eric B.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ AMPLITUDES ♦ DETECTION ♦ DOPPLER EFFECT ♦ METERS ♦ NOISE ♦ PLANETS ♦ POLAR-CAP ABSORPTION ♦ RADIAL VELOCITY ♦ RESOLUTION ♦ SATELLITES ♦ SIMULATION ♦ SPECTRA ♦ STARS
Abstract Photospheric velocities and stellar activity features such as spots and faculae produce measurable radial velocity signals that currently obscure the detection of sub-meter-per-second planetary signals. However, photospheric velocities are imprinted differently in a high-resolution spectrum than are Keplerian Doppler shifts. Photospheric activity produces subtle differences in the shapes of absorption lines due to differences in how temperature or pressure affects the atomic transitions. In contrast, Keplerian Doppler shifts affect every spectral line in the same way. With a high enough signal-to-noise (S/N) and resolution, statistical techniques can exploit differences in spectra to disentangle the photospheric velocities and detect lower-amplitude exoplanet signals. We use simulated disk-integrated time-series spectra and principal component analysis (PCA) to show that photospheric signals introduce spectral line variability that is distinct from that of Doppler shifts. We quantify the impact of instrumental resolution and S/N for this work.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2017-09-01
Publisher Place United States
Journal Astrophysical Journal
Volume Number 846
Issue Number 1


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