We present the first light curves in the infrared J and K filters of VV UMa and analyze them, together with a new set of BVR light curves obtained in different runs from 1997 to 2000. Based on the spectra of VV UMa and standard stars in the region 8440-8870 Å, we classify the primary component of the binary as a type A1.5-2 V star. Evidence of

We measured the bar pattern speed, Ωp , of the SB0 galaxy NGC 1023 using the Tremaine-Weinberg method with stellar-absorption slit spectroscopy. The morphology and kinematics of the Hi gas outside NGC 1023 suggest it suffered a tidal interaction, sometime in the past, with one of its dwarf companions. At present, however, the optical disc is

We investigate the diagnostic potential of polarimetric measurements with filtergraph instruments. Numerical simulations are used to explore the possibility of inferring the magnetic field vector, its filling factor, and the thermodynamics of model atmospheres when only a few wavelength measurements are available. The simulations assume the

Simultaneous broadband single images and time series of images have been obtained at λ0.8 and λ1.55 μm, which are at the extremes of the continuum absorption coefficient of the solar atmosphere. Active regions have been observed for different heliocentric angles. Weighted difference images between the two wavelength bands have been used to identify

Here we attempt to infer the recent history of star formation in the BCD galaxy VII Zw 403, based on an analysis that accounts for the dynamics of the remnant generated either by an instantaneous burst or by a continuous star formation event. The models are restricted by the size of the diffuse X-ray-emitting region, the Hα luminosity from the star

We present infrared photometry of the Galactic bulge X-ray binary systems GX 13+1 and GX 17+2 obtained in 1997 July and August using OSIRIS on the 1.8 m Perkins Telescope at Lowell Observatory. GX 13+1 clearly varies over ~0.6 mag in the K band. Our light curve suggests a modulation on a timescale of ~20 days, which is in agreement with previously