[Abridged] We discovered in the Herschel Reference Survey an extremely bright IR source with S_{500}~120mJy (Red Virgo 4 - RV4). Based on IRAM/EMIR and IRAM/NOEMA detections of the CO(5-4), CO(4-3), and [CI] lines, RV4 is located at z=4.724, yielding a total observed L_{IR} of 1.1+/-0.6x0^{14}L_{\odot}. At the position of the... Show more