ИСТИНА

We performed in September 2012 spectrophotometry of (145) Adeona, (704) Interamnia, (779) Nina, and (1474) Beira to specify mineralogy of the asteroid surface matter. According to widely used classifications, Adeona is of C or Ch type, Interamnia – of F or B, Nina – of M or X, and Beira – of FX or B. Comparing reflectance spectra of the asteroids with their spectra obtained by others, we discovered an unusual shape of Adeona’s, Interamnia’s, and Nina’s spectra manifesting itself in a considerable growth of spectral reflectivity predominantly in the range ~0.4-0.6 μm. Given the lack of such a feature in reflectance spectra of other asteroids observed at the observatory, with the same facility, closely in time and at similar atmospheric conditions, we suspected its belonging to just the bodies. We registered for the first time simultaneous cometary activity on four main-belt asteroids of primitive types, Adeona, Interamnia, Nina, and Beira. Given an abundant ice component on such bodies, the appearance of a temporary coma could repeat by impact events. However, the phenomenon may be mass for primitive asteroids at perihelion distances. To verify our suggestions and results, we need new observations of these and other asteroids at perihelion distances and at different viewing conditions