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The Robert Stobie Spectrograph is currently the prime spectroscopic instrument on the 11m Southern African Large Telescope (SALT), which is now in commissioning. The current visible beam of RSS was designed with spectropolarimetric versions of all its modes, imaging, grating spectroscopy (with Multi Object Spectroscopy capability) from 3200 to 9000 Å, and Fabry-Perot Spectroscopy from 4300 to 9000 Å, with spectral resolution up to R = 10000. The polarimetric field of view is 4×8 arcmin. The instrument was designed with an upgrade path leading to a simultaneous Near InfraRed beam (out to 1.7µm), now in development, which will duplicate the spectropolarimetric modes in the NIR. We describe results from early polarimetric commissioning of the visible beam. [ABSTRACT FROM AUTHOR]

Thorough understanding of the shock metamorphic signatures of zircon will provide a basis for the application of this mineral as a powerful tool for the study of terrestrial impact structures and formations. This paper of the cathodoluminescence (CL) spectroscopic signatures of naturally shocked zircon crystals from the Vredefort Dome, South Africa contributes to the understanding of the formation of microdeformation in zircon under very high pressures. All investigated shocked samples shows an inverse relationship between the brightness of the backscattered electron (BSE) signal and the corresponding cathodoluminescence intensity of the zonation patterns. The CL spectra of samples are characterised by narrow emission lines and broad bands in the region of visible light and in the near-ultraviolet range. The emission lines result from rare earth element activators and the broad bands are associated with lattice defects. The results show a clear relationship between the CL properties of zircon and shock pressure, which confirm the possible use of these methods as shock indicators. [ABSTRACT FROM AUTHOR]

We report the near-infrared (NIR) polarimetry of 34 young brown dwarfs (YBDs). This is the first NIR linear polarization survey for YBDs in the Taurus, rho Ophiuchi, and Chamaeleon dark clouds. The observations were conducted with SIRPOL on the IRSF 1.4-m telescope in South Africa. SIRPOL is a polarimeter which has the capability to conduct the JHKs simultaneous imaging polarimetry. Our targets are inferred to have circumstellar disks based on optical and NIR spectroscopy and their spectral energy distribution (SED). The spectral types of these targets range from M6.25 to M9.5 and the masses range from about 80 to 10 MJupiter. We have detected significant linear polarization from 16 YBDs. In previous studies for YBD disks, the observed SEDs have been well fit by the flat or flared disk models, thus we consider significant polarization of three YBDs is due to photon scattering by the dust in circumstellar disks rather than in envelopes. Highly polarized sources serve as ‘direct‘ evidence for possible disk systems, and thus, YBDs with significant intrinsic polarization are best targets for future high-resolution telescopes. [ABSTRACT FROM AUTHOR]