We report results of follow-up multicolor photometry of the optical variable source that is a probable remnant of the gamma-ray burst GRB970508 discovered by the BeppoSAX satellite (IAUC 6649). Observations were carried out in Johnson-Kron-Cousins BVR c I c system with the 1-m and 6-m telescopes of SAO RAS. Between the 2nd and the 5th day after the burst a fading of the remnant is well fitted with an exponential law in all four bands. During this period the 'broadband spectrum' of the object was unchanged and can be approximated by a power-law, F ν ∝ ν −1.1 . After the 5th day the decline of brightness is slowed down. In the R c band until the 32nd day, the light curve can be described by a power-law relation, F t ∝ t −1.2 .

We present the first photometry of individual stars within VV124 (UGC4879) and find that this is the most isolated dwarf galaxy in the periphery of the Local Group. This work is based on imaging and spectroscopic follow-up observations with the 6-m BTA telescope; we resolve VV124 into 1560 stars down to the limiting magnitude levels of V 25.6 and I 23.9. Young blue stellar populations and ionized gas are found near the core, but notably displaced from the centre of the galaxy as traced by dominant evolved red stars. The mean heliocentric radial velocity derived from the spectra of two blue supergiant stars and unresolved continuum sources is −70 ± 15 km s −1 . The evolved 'red tangle' stellar populations, which contain the red giant branch (RGB), are identified at large galactocentric radii. We use the I-band luminosity function to determine the distance based on the Tip of RGB method, 1.1 ± 0.1 Mpc. This is ∼10 times closer than the values usually assumed in the literature, and we provide revised distance-dependent parameters. From the mean (V − I) colour of the RGB, we estimate the mean metallicity as [Fe/H] −1.37 dex. Despite its isolated location, the properties of VV124 are clearly not those of a galaxy in formation, but rather similar to a transitional dIrr/dSph type.

A strong emission line at 6703Åhas been detected in the optical spectrum for the host galaxy (R=23.1) of the radio source RC J0311+0507 (4C+04.11). This radio galaxy, with a spectral index of 1.31 in the frequency range 365-4850 MHz, is one of the ultrasteep spectrum objects from the deep survey of a sky strip conducted with RATAN-600 in 1980RATAN-600 in -1981 We present arguments in favor of the identification of this line with Lyα at redshift z = 4.514. In this case, the object belongs to the group of extremely distant radio galaxies of ultrahigh radio luminosity (P 1400 = 1.3 × 10 29 W Hz −1 ). Such power can be provided only by a fairly massive black hole (∼ 10 9 M ⊙ ) that formed in a time less than the age of the Universe at the observed z (1.3 Gyr) or had a primordial origin.

No abstract

No abstract