We present the results of speckle interferometric observations of 273 magnetic stars most of which are Ap/Bp type. All observations were made at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We resolved 58 binary and 5 triple stars into individual components. Almost half of these stars were astrometrically resolved for the first time. The fraction of speckle interferometric binaries/multiples in the sample of stars with confirmed magnetic fields is 23%. We expect that the total fraction of binaries/multiples in the sample with account for spectroscopic short-period systems and wide common proper motion pairs can be twice higher. The detected speckle components have a prominent peak in the ρ distribution that corresponds to the closest resolved pairs. Full version of present paper is available in electronic form at http://arxiv.org/abs/1308.3168.

We present diffraction-limited speckle-masking observations of the central object HD 97950 in the giant HII region and star cluster NGC 3603. Twenty-eight stellar components have been detected in the 6.″3 x 6.″3 field from our reconstructed images. Four different filter combinations were used for the selection of distinct spectral regions comprising Hα emission, the main Wolf-Rayet and Of-type emission lines, and two continuum bands. Stellar components having WN-type characteristics have been found. A color-magnitude diagram has been constructed. Isochrone fits yield a cluster age of about 3.2 Myr, which is in accordance with the time-scale of Wolf-Rayet star evolution.

We report the observation of T Tau by visible speckle interferometry at the CFHT. The observations were carried out at two wavelengths simultaneously. Each image was split into two, allowing improved data processing. The 4-channel photon-counting detector CP40 was used. We have discovered that 30% of the total energy at Hα is emitted by an extended elliptical component, with a FWHM of 70 marcsec. In the neighbouring continuum, T Tau is not resolved by the 3.60 m CFHT. We briefly discuss the astrophysical consequences of this new result.