Award Abstract #9520443
Detecting Extra-Solar Planets: Crossing the Jupiter Threshold

NSF Org:	AST Division of Astronomical Sciences
Initial Amendment Date:	October 19, 1995
Latest Amendment Date:	November 10, 1999
Award Number:	9520443
Award Instrument:	Standard Grant
Program Manager:	J. P. Wright AST Division of Astronomical Sciences MPS Directorate for Mathematical & Physical Sciences
Start Date:	November 1, 1995
Expires:	December 31, 1999 (Estimated)
Awarded Amount to Date:	$331698
Investigator(s):	Geoffrey Marcy gmarcy@etoile.berkeley.edu (Principal Investigator) R. Paul Butler (Co-Principal Investigator)
Sponsor:	San Francisco State University 1600 Holloway Ave San Francisco, CA 94132 415/405-3943
NSF Program(s):	SPECIAL PROGRAMS IN ASTRONOMY
Field Application(s):	0000099 Other Applications NEC, 11 Astronomy
Program Reference Code(s):	SMET, 9229, 9178, 1207, 1215
Program Element Code(s):	1219

ABSTRACT

9520443 Marcy Our Solar System remains the lone planetary system that is known to be around a normal star. Current observational efforts have failed to discover extrasolar planets at a threshold of the mass three times that of Jupiter orbiting approximately 30 solar-type stars. A search for extrasolar planets, by observing the reflex acceleration of the hmst stars, measured by the Doppler effect, will be carried out. As our Sun executes a velocity amplitude change of 13 m/sec (as observed from outside the solar system) due primarily to Jupiter, it is planned to achieve a Doppler measurement precision of 2 m/sec to ensure detection of giant planets orbiting around other stars. This unprecedented Doppler measurement precision stems from novel developments in spec- trometer design and spectral analysis. In addition, a new Schmidt camera has been specially engineered to produce a sharp, symmetric Point Spread Function (PSF) over the full format of a fast echelle spectrometer. A 2048x2048 CCD detector will be used to gather all stellar Doppler information, within 1000 Angstroms wavelength, spread over 30,000 CCD pixels. The analysis of the Doppler shifts in the spectra will consist of an entirely novel simultaneous solution of all spectrometer parameters (wavelength scale and PSF) and Doppler shift. A detailed error budget for the Doppler measurements yields a bottom line accuracy of 2 m/sec. This precision renders the detection of Jupiter-like planets detectable at the 5 sigma level, and Saturn-like planets will be marginally detectable. Actual test observations of the spectra of Solar-like stars enable one to achieve a precision of 3.5 m/sec. This accuracy will be improved with the next-generation Doppler analysis techniques. Already, however, by averaging sets of five exposures, the error in the mean is less than 2 m/sec. It is planned to monitor 15 G-type and K- type stars and make measurements of the Doppler wavelength shifts to a precision of 2 m/sec. Eighty five other stars will be observed with an accuracy of 5 m/sec in the measurement of the Doppler wavelength shifts (depending on the brightness of the individual stars). These new techniques will make it possible to observe stars and measure velocity changes, indicative of giant planets, within 3 years.

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