28.18-P

Does tex2html_wrap_inline12 Boo Really Have a Planetary Companion?

W. D. Cochran, A. P. Hatzes (University of Texas)

The claimed detection of photospheric line profile variability in 51 Peg by Gray (1997) and the resulting controversy over whether the observed radial velocity variations of that stars are the result of stellar reflex motion due to a planetary companion or are a manifestation of stellar pulsation has prompted us to search for similar spectral variability in tex2html_wrap_inline12 Boo. This star shows radial velocity variations with an even smaller period (3.31 days) and a velocity amplitude (469ms tex2html_wrap_inline16 ) eight times larger than that of 51 Peg. If tex2html_wrap_inline12 Boo is also merely a pulsating star (as Gray claims is true of 51 Peg), then it should show line profile variations much larger than those seen in 51 Peg. We used the high resolution (R = 230,000) mode of the 2dcoudé spectrograph of the McDonald Observatory 2.7m Harlan Smith Telescope to observe tex2html_wrap_inline12  Boo in January, March and May 1997. The results of the line bisector analysis are presented, and their implications for the existence of planets in very short period orbits are discussed.