We have studied Leo A -the isolated and extremely gas rich dwarf irregular galaxy of very low stellar mass and metallicity. Ages of the stellar populations in Leo A are ranging from ∼10 Myr to ∼10 Gyr. Here we report the discovery of an old stellar halo and a sharp stellar edge. Also we find the distribution of stars extending beyond the gaseous envelope of the galaxy. Therefore, Leo A by its structure as well as stellar and gaseous content is found to resemble massive disk galaxies. This implies that galaxies of very low stellar mass are also able to develop complex structures, challenging contemporary understanding of galaxy evolution.

We have carried out a survey of compact star clusters (apparent size 3 ′′ ) in the southwest part of the M31 galaxy, based on the high-resolution Suprime-Cam images (17.5 ′ × 28.5 ′ ), covering ∼15% of the deprojected galaxy disk area. The U BV RI photometry of 285 cluster candidates (V 20.5 mag) was performed using frames of the Local Group Galaxies Survey. The final sample, containing 238 high probability star cluster candidates (typical half-light radius r h ∼ 1.5 pc), was selected by specifying a lower limit of r h 0.15 ′′ ( 0.6 pc). We derived cluster parameters based on the photometric data and multiband images by employing simple stellar population models. The clusters have a wide range of ages from ∼5 Myr (young objects associated with 24 µm and/or Hα emission) to ∼10 Gyr (globular cluster candidates), and possess mass in a range of 3.0 log(m/m ⊙ ) 4.3 peaking at m ∼ 4000 m ⊙ . Typical age of these intermediate-mass clusters is in the range of 30 Myr t 3 Gyr, with a prominent peak at ∼70 Myr. These findings suggest a rich intermediate-mass star cluster population in M31, which appears to be scarce in the Milky Way galaxy.

We report the discovery of an extended globular-like star cluster, M 33-EC1, at the outer edge of the spiral galaxy M 33. The distance to the cluster is 890 kpc, and it lies at a projected distance of 12.5 kpc from the center of M 33. Old age ( 7 Gyr) and low metallicity ([M/H] −1.4) are estimated on the basis of isochrone fits. Color-magnitude diagrams of stars, located in the cluster's area, and photometric and structural parameters of the cluster are presented. The cluster's luminosity (M V = −6.6) and half-light radius (r h = 20.3 pc) are comparable to those of the extended globular clusters, discovered in more luminous Local Group galaxies, the Milky Way and M 31. Extended globular clusters are suspected to be remnants of accreted dwarf galaxies, and the finding of such a cluster in the late-type dwarf spiral galaxy M 33 would imply a complex merging history in the past.

Extensive light and colour curves for the Type Ia supernova (SN Ia) SN 2002er are presented as part of the European Supernova Collaboration. We have collected UBVRI photometry from 11 different telescopes covering the phases from 7 d before until 619 d after maximum light. Corrections for the different instrumental systems and the non-thermal spectrum of the supernova (S-corrections) have been applied. With the densely sampled light curves we can make detailed comparisons to other well-observed objects. SN 2002er most closely resembles SN 1996X after maximum, but clearly shows a different colour evolution before peak light and a stronger shoulder in V and R bands compared to other well-observed SNe Ia. In particular, the rise time appears to be longer than what is expected from the rise time versus decline rate relation. We use several methods to determine the reddening towards SN 2002er based on the colour evolution at near peak and at late phases. The uvoir (bolometric) light curve shows great similarity with SN 1996X, but also indications of a higher luminosity, longer rise time and a more pronounced shoulder 25 d past maximum. The interpretation of the light curves was carried out with two independent light curve codes. Both find that given the luminosity of SN 2002er the 56 Ni mass exceeds 0.6 M with preferred values near 0.7 M . Uncertainties in the exact distance to SN 2002er are the most serious limitation of this measurement. The light-curve modelling also indicates a high level of mixing of the nickel in the explosion of SN 2002er.

A new survey of star clusters in the southwest field of the M31 disk based on the high resolution Subaru Suprime-Cam observations is presented. The UBV RI aperture CCD photometry catalog of 285 objects (V 20.5 mag; 169 of them identified for the first time) is provided. Each object is supplemented with multiband color maps presented in the electronic edition of the Astrophysical Journal Supplement. Seventy seven star cluster candidates from the catalog are located in the Hubble Space Telescope archive frames.