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The Suzaku X-ray satellite observed the young stellar object V1647 Ori on2008 October 8 during the new mass accretion outburst reported in August 2008.During the 87 ksec observation with a net exposure of 40 ks, V1647 Ori showed ahigh level of X-ray emission with a gradual decrease in flux by a factor of 5and then displayed an abrupt flux increase by an order of magnitude. Suchenhanced X-ray variability was also seen in XMM-Newton observations in 2004 and2005 during the 2003-2005 outburst, but has rarely been observed for otheryoung stellar objects. The spectrum clearly displays emission from Helium-likeiron, which is a signature of hot plasma (kT ~5 keV). It also shows afluorescent iron Kalpha line with a remarkably large equivalent width of ~600eV. Such a large equivalent width suggests that a part of the incident X-rayemission that irradiates the circumstellar material and/or the stellar surfaceis hidden from our line of sight. XMM-Newton spectra during the 2003-2005outburst did not show a strong fluorescent iron Kalpha line, so that thestructure of the circumstellar gas very close to the stellar core that absorbsand re-emits X-ray emission from the central object may have changed in between2005 and 2008. This phenomenon may be related to changes in the infraredmorphology of McNeil's nebula between 2004 and 2008.

Suzaku Observation of Strong Fluorescent Iron Line Emission from the Young Stellar Object V1647 Ori during Its New X-ray Outburst