Polarimetry of the NGC 2261/R Monocerotis system and the faint jetlike feature to its southwest

Optical linear polarization maps of the region to the south of the NGC 2261/R Mon system show that the faint linear feature reported in 1985 by Walsh and Malin is reflection nebulosity directly illuminated by the star. The authors believe that it is the bright western rim of the highly obscured southern outflow from R Mon. The northern outflow, comprising the cometary nebular NGC 2261, shows polarization orientations that rotate with wavelength, deviating from the pattern expected in a simple reflection nebula. An explanation is offered involving an extensive magnetic field associated with the nebula, and the implications for magnetic acceleration of bipolar flows are discussed. 13 references