Towards Understanding Stellar Radial Velocity Jitter as a Function of   Wavelength: The Sun as a Proxy
  Using solar spectral irradiance measurements from the SORCE spacecraft and the F/F' technique, we have estimated the radial velocity (RV) scatter induced on the Sun by stellar activity as a function of wavelength. Our goal was to evaluate the potential advantages of using new near-infrared (NIR) spectrographs to search for low-mass planets around bright F, G, and K stars by beating down activity effects. Unlike M dwarfs, which have higher fluxes and therefore greater RV information content in the NIR, solar-type stars are brightest at visible wavelengths, and, based solely on information content, are better suited to traditional optical RV surveys. However, we find that the F/F' estimated RV noise induced by stellar activity is diminished by up to a factor of 4 in the NIR versus the visible. Observations with the upcoming future generation of NIR instruments can be a valuable addition to the search for low-mass planets around bright FGK stars in reducing the amount of stellar noise affecting RV measurements. 
Robert C. Marchwinski (1 and 2), Suvrath Mahadevan (1 and 2), Paul   Robertson (1 and 2), Lawrence Ramsey (1 and 2), and Jer...
astro-ph.SR astro-ph.EP