The AFOE: A Spectrograph for Precise Stellar Radial Velocity Measurements

Picture of the truck carrying the AFOE instrument up to Mt Wilson
The AFOE is being re-installed at the 100-Inch Hooker Telescope located at the Mt. Wilson Observatory (CA). It will be used to continue our exo-planet search project and to support the JPL/SIM Grid project.
The instrument has been reassembled and is being modified to mate with the telescope. We anticipate re-commissioning in November or December 2004 and routine observations in January 2005.

The Instrument

The Advanced Fiber-Optic Echelle (AFOE) spectrometer is a fiber-fed, bench-mounted echelle spectrograph, initially located at the 1.5m (60") telescope of the Whipple Observatory, near Tucson, Arizona.
The AFOE is being relocated at the Mt. Wilson 100" telescope.

The AFOE instrument has been packed and moved to Mt. Wilson (mid-May) where it is being reassembled and modified as needed. We anticipate to resume observing in January 2005.

A spectrograph is an instrument that spreads out light into its spectral components (i.e,, its different colors); it is a sophisticated version of a prism, and like a prism it spreads out the incoming light into a rainbow.

An echelle spectrograph spreads out the spectral components in both X and Y directions (folding the rainbow into stacked segments like a ladder, echelle in French) to better fill a 2-D detector (like a CCD camera).

Check out our more technical description of the AFOE.

The AFOE Projects

The AFOE is used for several scientific projects:

The Chronology

The AFOE was initially a joint project of the Smithsonian Astrophysical Observatory (SAO) and the High Altitude Observatory (HAO).
The AFOE has been recently upgraded to improve it's efficiency - while restricting it's use to the Iodine wavelength range (description coming soon).
The AFOE is in the process of being re-installed at the 100-Inch Hooker Telescope located at the Mt. Wilson Observatory, CA, to provide radial velocities for the JPL/SIM Grid project, while resuming our exo-planet search.

The Players

Currently the AFOE team consists of The following people have also contributed to the AFOE project:

Our Sponsors

Research with the AFOE is supported by the Smithsonian Institution (SI), the National Aeronautics & Space Administration (NASA), and the National Science Foundation (NSF).
Sylvain G. Korzennik  (
Last modified: Fri Oct 22 17:21:20 2004