TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2052 SUBJECT: GRB 030329: fading X-ray afterglow with RXTE DATE: 03/03/31 22:56:08 GMT FROM: Frank Marshall at GSFC F.E. Marshall (NASA/GSFC), C. Markwardt (U.Md. & NASA/GSFC), and J.H. Swank (NASA/GSFC) report: RXTE re-observed GRB 030329 for a total of 3.9 ks starting at March 30.724 UT (about 1.240 days after the burst). The flux was about 0.9e-11 ergs/s/cm**2 in the 2-10 keV band or about 15 times weaker than during the RXTE observation the previous day (Marshall and Swank, GCN 1996). The total light curve is well described by a simple model in which the flux decays as t^(-1.5). More complicated models are also consistent with the sparsely sampled data. For example, a model in which the decay rate increases from t^(-1.1) at early times (Burenin et al., GCN 2024) to t^(-1.934) at late times (Garnavich et al., GCN 2018; Smith, GCN 2019; Halpern et al., GCN 2021) fits the data if the break occurs 0.54 days after the burst.