Outburst of LS V+44 17 observed by MAXI and RXTE discovery of dip structure in pulse profile

We report the discovery of a dip structure in the pulse pro le of Be/X-ray binary LS V +44 17 observed by RXTE during an outburst detected by MAXI. The outburst was rst transient activity of LS V +44 17 since 1997 when the source was identi ed as a Be/X-ray binary. After the discovery with MAXI, the RXTE observations provided a pulse pro le with a narrow dip structure in the soft X-ray band (3 10 keV). Our pulse-phase-resolved spectroscopy showed that the absorption column density at the dip phase is much higher than those at the other intervals. Thus we can conclude that the partial eclipse of the emission region by the accretion column of the neutron star causes the dip structure in the pulse pro le of LS V +44 17 during the rst outburst.