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In this paper we present a temporal and spectral analysis of X-ray data fromthe XMM and Chandra observations of the ultrasoft and variable Seyfert galaxyRX J1301.9+2747. In both observations the source clearly displays two distinctstates in the X-ray band, a long quiescent state and a short flare (oreruptive) state which differs in count rates by a factor of 5--7. Thetransition from quiescent to flare state occurs in 1--2 ks. We have observedthat the quiescent state spectrum is unprecedentedly steep with a photon indexGamma~7.1, and the spectrum of the flare state is flatter with Gamma~4.4.X-rays above 2 keV were not significantly detected in either state. In thequiescent state, the spectrum appears to be dominated by a black body componentof temperature about ~30--40 eV, which is comparable to the expected maximumeffective temperature from the inner accretion disk. The quiescent statehowever, requires an additional steep power-law, presumably arising from theComptonization by transient heated electrons. Optical spectrum from the SloanDigital Sky Survey shows Seyfert-like narrow lines for RX J1301.9+2747, whilethe HST imaging reveals a central point source for the object. In order toprecisely determine the hard X-ray component, future longer X-ray observationsare required. This will help constrain the accretion disk model for RXJ1301.9+2747, and shed new light into the characteristics of the corona andaccretion flows around black holes.

RX J1301.9+2747: A Highly Variable Seyfert Galaxy with Extremely Soft X-ray Emission