The AFOE: A Spectrograph for Precise Stellar Radial
The AFOE is being re-installed at the
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 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"
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
Check out our more technical description of the
The AFOE Projects
The AFOE is used for several scientific projects:
Extrasolar Planet Detection
The search for planets outside our solar system. The AFOE can detected in the spectrum of a star
the gravitationally induced wobble of a star by an orbiting planet.
The study of stellar oscillations (star-quakes) in stars like our
Cepheid Pulsations and Distance Scale
The study of the pulsations of Cepheids (i.e,, a class of stars)
that are used to determine precisely the distance scale in our Universe.
The study of oscillations in stars like delta-Scuti
(i.e,, a class of stars that are somewhat larger and hotter than
the Sun, and that pulsate with periods of an hour or so).
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.
Currently the AFOE team consists of
The following people have also contributed to the AFOE project:
- Peter Nisenson (SAO, deceased June 21st, 2004)
- Timothy M. Brown (HAO)
- David Charbonneau (Harvard)
- Adam R. Contos (SAO)
- Scott D. Horner (USNO)
- Saurabh Jha (Harvard)
- Edward J. Kennelly (AER, Inc.)
- Martin Krockenberger (SAO)
- Robert W. Noyes (SAO)
Research with the AFOE is supported by the Smithsonian Institution
the National Aeronautics & Space Administration
and the National Science Foundation
Sylvain G. Korzennik
Last modified: Fri Oct 22 17:21:20 2004