Period derivative of the Soft Gamma-ray Repeater SGR 1627-41

After nearly a decade of quiescence, the soft gamma-ray repeater SGR 1627-41 reactivated on 2008 May 28 with a bursting episode (Esposito et al. 2008, MNRAS, 390, L34). On 2008 September 27-28 we performed an XMM-Newton target of opportunity observation of the source and discovered its long-sought spin period at 2.594578(6) s (Esposito et al. 2009, ApJ, 690, L105). We searched in the archival Chandra data of SGR 1627-41 taken on 2008 June 03 (obsID 9126, ATEL #1564 by Woods et al.) for the presence of a periodic signal over a period range extrapolated from our XMM-Newton data, assuming a period derivative dP/dt < 10-9 s s-1.