We have used all available radio-source surveys to construct the continuum spectra for sources in an area of 5 by 10 degrees near the North Ecliptic Pole (NEP), previously observed at 2.7 GHz with the Effelsberg telescope. Most of the surveys are of similar angular resolution (~3 to 5 arcmin) and cover a wide range of frequencies from 38 MHz to 5

Results of cooperative optical observations of EV Lac in September 1991 are presented. During 50 hours of photoelectric monitoring more than 40 flares were detected, including several events of moderate power and one very strong flare with amplitude {DELTA}U=3.7mag and duration of about half hour. Detailed colour analysis of this strong flare

Not Available

Not Available

Not Available

The magnetic flux tubes that rise across the convection zone to produce active regions are shown to develop a difference in inclination between their preceding and follower sides. This asymmetry is such that the following wing is more vertical (i.e., closer to the radial direction) than the preceding side. An asymmetry of this kind can be obtained