INTERSTELLAR EXTINCTION, POLARIZATION, AND GRAIN ALIGNMENT IN THE HIGH-LATITUDE MOLECULAR CLOUD TOWARD HD-210121

We present near-infrared photometry and optical and near-infrared pola rimetry for the line of sight toward HD 210121, obscured by the high-l atitude cloud DBB 80. From the data, we determine remarkably small val ues of the ratio of total to selective extinction, R(v) = 2.1 +/- 0.5 and the wavelength of maximum polarization, lambda(max) = 0.38 +/- 0.0 3 mu m, as compared to average values in the diffuse Galactic interste llar medium. These values nevertheless follow the linear relationship between R(V) and lambda(max) seen closer to the Galactic plane. Our re sults imply an abundance of small grains, which we interpret as eviden ce for lack of grain growth in this high-latitude cloud. This is consi stent with previous observations of high molecular abundances and extr emely steep far-ultraviolet extinction toward the star and also with t he presence of mid-infrared emission in the foreground cloud. We show that populations of small grains responsible for extinction and polari zation in DBB 80 respond to prevailing physical conditions in a correl ated way. Based on its extremely short value of lambda(max), we predic t that the line of sight to HD 210121 will be highly polarized in the ultraviolet.