El sistema de cúmulos globulares de NGC 1387

We present preliminary results from a study of the globular cluster system of NGC 1387, a low-luminosity S0 galaxy in the Fornax Cluster which is located at a projected distance of about 100 kpc from NGC 1399, the central galaxy of this cluster. This study is based on images from the wide-field MOSAIC Imager on the CTIO 4-m telescope, obtained with Washington C and Kron-Cousins R filters. The images cover a field of 36' × 36', corresponding to 200 × 200 kpc at the Fornax distance. This system was originally studied by Grebel & Richtler (1990). Afterwards, by means of (V, I) photometry, Kissler-Patig et al. (1997) obtained a high mean metallicity for the globular clusters ([Fe/H] = 0.5) and found no evidence of multiple populations. According to our results, which are based on photometry with better metallicity resolution, the globular cluster system of NGC 1387 presents interesting characteristics:

- It has a bimodal color-distribution, a feature that has been detected in few low-luminosity galaxies.

- The red globular clusters are notably over-abundant with respect to the blue ones, and extend to much redder colors than in other globular cluster systems. We found for the red peak position a colour (C-T₁) = 1.82, which corresponds to a metallicity [Fe/H] = -0.11. Until now, no other globular cluster system with such color distribution has been found.