2005MNRAS.364..725O

In order to study the inner parts of the circumstellar material around optically faint infrared bright objects, we present the first medium-resolution spectropolarimetric data taken in the near-infrared. In this paper, we discuss Paβ line data of GL 490, a well-known embedded massive young stellar object, and of MWC 349A and MWC 342, two optically faint stars that are proposed to be in the pre-main-sequence phase of evolution. As a check on the method, the classical Be star ζ Tau, known to display line polarization changes at optical wavelengths, was observed as well. Three of our targets show a `line effect' across Paβ. For ζ Tau and MWC 349A, this line effect is due to depolarization by a circumstellar electron-scattering disc. In both cases, the position angle of the polarization is consistent with that of the larger scale discs imaged at other wavelengths, validating infrared spectropolarimetry as a means to detect flattening on small scales. The tentative detection of a rotation in the polarization position angle at Paβ in the embedded massive young stellar object GL 490 suggests the presence of a small-scale rotating accretion disc with an inner hole - similar to those recently discovered at optical wavelengths in Herbig Ae and T Tauri stars.