  From adaptive optics observations with the Palomar 5-meter telescope we place
upper limits on the masses of any planetary companions located between ~30-230
AU away from Vega, where our data are sensitive to depths ranging from H=12.5
mag to H=19.0 mag fainter than Vega itself. Our observations cover a
plus-shaped area with two 25"x57" elements, excluding 7"x7" centered on the
star. We have identified 2 double and 4 single point sources. These projected
companions are 14.9-18.9 mag fainter than Vega, and if physically associated
would have masses ranging from 4 to 35 Mjup and orbital radii 170-260 AU.
Recent simulations of dusty rings around Vega predict the presence of a
perturbing body with mass <2-3 Mjup and orbital radius ~40-100 AU, though more
massive (~10 Mjup) planets cannot be excluded. None of the detected objects are
this predicted planet. Based on a color-magnitude, spectroscopic, and proper
motion analysis, all objects are consistent with being background sources.
Given the glare of Vega, a 2 Mjup object near the expected orbital radii would
not have been visible at the 5-sigma level in our data, though any >10 Mjup
brown dwarf could have been seen at separation >80 AU.
