TITLE:   GCN CIRCULAR
NUMBER:  8118
SUBJECT: Discovery of  the Spin Period of the New Soft Gamma Repeater SGR 0501+4516
DATE:    08/08/22 21:39:33 GMT
FROM:    Chryssa Kouveliotou at MSFC  <chryssa.kouveliotou@nasa.gov>

E. Gogus (Sabanci University), P. Woods (Dynetics), and C. Kouveliotou
(NASA/MSFC), report on behalf of a larger collaboration:

We triggered our SGR ToO Program with RXTE following the Swift detection
of a burst from the new Soft Gamma Repeater SGR 0501+4516 (Barthelmy et
al. 2008, GCN # 8113). A 600 s RXTE observation started on 2008 August
22, 16:39:09 UT. During this pointing we detected one short SGR
burst-like event in the PCA data (2-60 keV), confirming that the new
source was in the field of view. We searched for a spin period for the
new SGR in the 2.5-13.5 keV band PCA event mode data and detected a
coherent signal (barycenter corrected) at 0.17334 Hz, corresponding to a
spin period of 5.769 +- 0.004 s.

A longer RXTE observation of SGR 0501+4516 is currently underway.  We
thank the RXTE planner, Divya Pereira, for prompt scheduling.