Chromospheric Activity and Jitter Measurements for 2630 Stars on the California Planet Search

Abstract

We present time series measurements of chromospheric activity for more than 2600 main sequence and subgiant stars on the California Planet Search (CPS) program with spectral types ranging from about F5V to M4V for main sequence stars and from G0IV to about K5IV for subgiants. The large data set of more than 44,000 spectra allows us to identify an empirical baseline floor for chromospheric activity as a function of color and height above the main sequence. We define $\Delta S$ as an excess in emission in the Ca II H\&K lines above the baseline activity floor and define radial velocity jitter as a function of $\Delta S$ and \bv\ for main sequence and subgiant stars. Although the jitter for any individual star can always exceed the baseline level, we find that K dwarfs have the lowest level of jitter. The lack of correlation between observed jitter and chromospheric activity in K dwarfs suggests that the observed jitter is dominated by instrumental or analysis errors and not astrophysical noise sources. Thus, given the long-term precision for the CPS program, radial velocities are not correlated with astrophysical noise for chromospherically quiet K dwarf stars, making these stars particularly well-suited for the highest precision Doppler surveys. Chromospherically quiet F and G dwarfs and subgiants exhibit higher baseline levels of astrophysical jitter than K dwarfs. Despite the fact that the \rms\ in Doppler velocities is correlated with the mean chromospheric activity, it is rare to see one-to-one correlations between the individual time series activity and Doppler measurements, diminishing the prospects for correcting activity-induced velocity variations.

17 figures, two large tex tables, accepted ApJ

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• A spectroscopically confirmed Gaia-selected sample of 318 new young stars within $\sim$200 pc
• Detection of p-mode Oscillations in HD 35833 with NEID and TESS
• A Crystallizing White Dwarf in a Sirius-Like Quadruple System
• A Jupiter-mass planet around the K0 giant HD 208897
• The Lick-Carnegie Survey: A New Two-Planet System Around the Star HD 207832
• Searching for new young stars in the northern hemisphere: The Pisces Moving Group
• Spectroscopic orbits of ten nearby solar-type dwarfs
• The Fundamental Stellar Parameters of FGK Stars in the SEEDS Survey
• Fine Structure of the Age-Chromospheric Activity Relation in Solar-Type Stars: II. H$\alpha$ Line
• Magnetic activity of the solar-like star HD 140538
• A Homogeneous Catalog of Oscillating Solar-Type Stars Observed by the Kepler Mission and a New Amplitude Scaling Relation Including Chromospheric Activity
• Properties of F Stars with Stable Radial Velocity Timeseries: A Useful Metric for Selecting Low-jitter F Stars
• A multi-wavelength view of the multiple activity cycles of $\epsilon$~Eridani
• Ultraviolet Flux Decrease Under a Grand Minimum from IUE Short Wavelength Observation of Solar Analogs
• Fiber scrambling for high-resolution spectrographs. II. A double fiber scrambler for Keck Observatory
• Stellar Chromospheric Activity Database of Solar-like Stars Based on the LAMOST Low-Resolution Spectroscopic Survey: II. the bolometric and photospheric calibration
• A Stellar Activity F-statistic for Exoplanet Surveys (SAFE)
• Quiet Please: Detrending Radial Velocity Variations from Stellar Activity with a Physically Motivated Spot Model
• The TESS-Keck Survey. XIII. An Eccentric Hot Neptune with a Similar-Mass Outer Companion around TOI-1272
• KOBE-1: The first planetary system from the KOBE survey. Two planets likely residing in the sub-Neptune mass regime around a late K-dwarf
• Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391
• H${}_{\alpha }$-activity and ages for stars in the SARG survey
• The CARMENES search for exoplanets around M dwarfs. The impact of rotation and magnetic fields on the radial velocity jitter in cool stars
• SEEDS direct imaging of the RV-detected companion to V450 Andromedae, and characterization of the system
• MagAO Imaging of Long-period Objects (MILO). II. A Puzzling White Dwarf around the Sun-like Star HD 11112
• Data Reduction Pipeline of the TOU Optical Very High Resolution Spectrograph and Its sub-m/s Performance
• Fundamental parameters and abundance analysis of the components in the SB2 system HD 60803
• New Dynamical State and Habitability of the HD 45364 Planetary System
• Planetary system architectures with low-mass inner planets: Direct imaging exploration of mature systems beyond 1 au
• Meridional flow velocities on solar-like stars with known activity cycles
• Sunstardb: a database for the study of stellar magnetism and the solar-stellar connection
• A Trio of Giant Planets Orbiting Evolved Star HD 184010
• Empirical Relations for the Sensitivities of Solar-like Oscillations to Magnetic Perturbations
• Precise Masses and Orbits for Nine Radial Velocity Exoplanets
• A Hermite-Gaussian Based Radial Velocity Estimation Method
• Stellar Characterization and a Chromospheric Activity Analysis of a K2 Sample of Planet-Hosting Stars
• Radial velocity analysis of stars with debris discs
• Revisiting $\epsilon$ Eridani with NEID: Identifying New Activity-Sensitive Lines in a Young K Dwarf Star
• The Solar Neighborhood. LV. M Dwarf Twin Binaries -- One in Five Twin Sibling Pairs Are Mismatched in Activity and/or Rotation
• The California Legacy Survey I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades
• The TESS-Keck Survey. XIX. A Warm Transiting Sub-Saturn Mass Planet and a non-Transiting Saturn Mass Planet Orbiting a Solar Analog
• An investigation of the magnetic activity of HD 134319 based on TESS photometry and ground-based spectroscopy
• SPORES-HWO. II. Companion Mass Limits and Updated Planet Properties for 120 Future Exoplanet Imaging Targets from 35 yr of Precise Doppler Monitoring
• Multi-Wavelength High-Resolution Spectroscopy for Exoplanet Detection: Motivation, Instrumentation and First Results
• The TESS-Keck Survey. XI. Mass Measurements for Four Transiting sub-Neptunes orbiting K dwarf TOI-1246
• Magnetism and activity of planet hosting stars
• Granulation on a quiet K dwarf: HD 166620 I. Spectral signatures as a function of line-formation temperature
• The SOL $\text{(Solar Origin and Life)}$ Project: Detailed characterization of candidates for the ZAMS and Subgiant stages
• HD 166620: Portrait of a Star Entering a Grand Magnetic Minimum