Open cluster in NGC 330 in SMC

3-sec exposure of a field in the Small Magellanic Cloud, centred on the open star cluster NGC 330. The electronic overlay indicates the positions of the 19 slits used for FORS1 multi-object spectroscopy.

This is a reproduction from a 3 sec exposure of NGC 330 (no filter), obtained in order to ensure the correct positioning of the individual slits during the subsequent MOS observation. The field measures 6.8 x 6.8 arcmin; North is up and East is left. The spectra shown in ESO Press Photo eso9846d were taken with FORS1 grism 600B on October 2, 1998. The slit width was 1 arcsec, the seeing conditions were good (0.7 arcsec) and the exposure time was 6 min. From left to right, the useful wavelength range is from 350 nm (ultraviolet) to 590 nm (yellow) and the spectral resolution is 815, i.e. about 0.6 nm at 500 nm. The CCD detector has 2048 x 2048 pix, each measuring 24 x 24 µm. The tracing in eso9846e is of the spectrum registered through slit no. 4 from the top in  eso9846c and centred on star "Be41".