Detection of a 5 Hz quasi-periodic oscillation from X-ray nova GRS 1739-278

The X-ray nova GRS 1739-278 flared up near the Galactic center in the spring of 1996. Here we report on the discovery of an similar to 5 Hz quasi-periodic oscillation (QPO) in Rossi X-Ray Timing Explorer/PCA observations of GRS 1739-278. The QPO was only present when the source was in its very high state and disappeared later, when it made a transition down into the high state. We present the energy spectra of this black hole candidate measured in both high and very high states and discuss the similarities between this system and other X-ray transients.