A large set of high-precision, full-Stokes spectro-polarimetric observations of prominences in He I D3, Hα, and Hβ lines has been recorded with the ZIMPOL polarimeter at the Gregory-Coudé Telescope in Locarno. The observational technique allows us to obtain measurements free from seeing-induced spurious effects. The instrumental polarization is

The polarization spectrum of OJ287 was obtained during the 1993/94 observing campaign within the OJ-94 International Collaboration. Data were taken on December 17-18-19/1993, an on Januarty 11-12/1994. Between both periods of observations, OJ287 showed minor flare activity, where brightness raised from V=15.75 to V=15.25, and the polarization

Planetary nebula NGC6543 has a complex structure with a central hot bubble showing both point- and plane symmetry, and a large outer halo that is likely interacting with the local ISM. Between these two structures the HST has revealed a series of a least nine regularly spaced concentric circular rings that are faint and have low contrast. The

We report on the near-infrared (JHK-bands) low-resolution spectroscopy and red optical (Z-band) photometry of seven proper-motion, very low-mass substellar member candidates of the Pleiades cluster with magnitudes in the interval J = 17.5-20.8 and K = 16.1-18.5 mag. Spectra were acquired for six objects with the LIRIS and NIRSPEC instruments

Using CGS4 on UKIRT, we have obtained a 1.95-2.45 micron infrared spectrum of the primary candidate counterpart to the bright Z low-mass X-ray binary (LMXB) GX5-1. IR photometry by Naylor, Charles, & Longmore (1992) and the astrometry of Jonker et al. (2000) had previously identified this star as the most likely counterpart to GX5-1. The spectrum

Convective line asymmetries in the optical spectrum of two metal-poor stars, Gmb 1830 and HD 140283, are compared to those observed for solar metallicity stars. The line bisectors of the most metal-poor star, the subgiant HD 140283, show a significantly larger velocity span that the expectations for a solar-metallicity star of the same spectral