Aims. The nearby barred spiral NGC2903 has an active starburst at its centre and H IIH IIregionsdistributed along its bar. We analyse the star-formation properties inthe bar region of NGC2903 and study its links to the typical barmorphological features. Methods. We combine space and ground-based data from thefar-ultraviolet to the sub-millimeter spectral ranges to create apanchromatic view of the NGC2903 bar. We produce two catalogues:one for the current star-formation regions, as traced by the Hcompactemission, and a second for the ultraviolet (UV) emitting knots,containing positions and luminosities. From them, we obtain ultravioletcolours, star-formation rates, dust attenuation, and HEWs, and analyse their spatial distribution. We estimate stellar cluster ages using stellar population synthesis models (Starburst99). Results. We find NGC2903 to be a complex galaxy that has a very different morphology in each spectral band. The CO(J=1-0) and the 3.6m emission trace each other in a clear barred structure, while the Hleadsboth components and has an s-shape distribution. The UVemissionis patchy and does not resemble a bar. The UVemission is alsocharacterised by a number of regions located symmetrically with respectto the galaxy centre, almost perpendicular to the bar, in a spiralshape covering the inner 2.5kpc. These regions exhibit a significant amount of neither Hnor 24memission. We estimate ages for these regions ranging from 150 to320Myr, older than the remaining UVknots, which have ageslower than 10Myr. The SFR calculated from the UVemissionis0.4yr-1, compatible with the SFR derived from Hcalibrations (1yr-1). Key words: galaxies: star formation - galaxies: structure -galaxies: individual: NGC2903 - galaxies: evolution - HII regions- ultraviolet: galaxies
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