Abstract:  EXPRES (the Extreme PREcision Spectrograph) is a R~137,000, fiber-fed, optical spectrograph installed at the 4.3-m Lowell Discovery Telescope near Flagstaff, Arizona.  I will give an overview of the optical design, commissioning, and software development that has gone into EXPRES.  The instrument itself has demonstrated a stability of 4-7 cm/s.  We have constructed an optimal-extraction based pipeline that returns on-sky, single-measurement precision of ~30 cm/s for observations with S/N of 250.   I will highlight Excalibur, a hierarchical, non-parametric method for wavelength calibration.  Recent EXPRES data of known planetary systems show sub-m/s residual RMS.  EXPRES data is also being used for a community-wide "Activity Challenge" to diagnose stellar photospheric velocities.

Host:  Eric Ford

Please click the link to join the webinar: https://psu.zoom.us/j/96060188956