TITLE: GCN GRB OBSERVATION REPORT NUMBER: 789 SUBJECT: False GRB alarm from RXTE/ASM on 8 Sept 2000 DATE: 00/09/11 14:27:37 GMT FROM: Don Smith at MIT iD. A. Smith (UofMich) and A. M. Levine (MIT) report on behalf of the ASM team at MIT: For those of you who received the RXTE_ASM TRANSIENT RAPID POSITION NOTICE over the GCN on Fri Sep 8 at 14:00:27 GMT, you should know that the ASM seems to have developed a systematic error in the data analysis pipeline. This error leads to known sources being misidentified as new, unknown, TOO sources, with associated error boxes that tend to cross, triggering the automatic alert system. The ASM team is working to identify and correct this error, and in the meantime we have disabled the automatic alert distribution function. We hope this false alarm did not cause too much confusion, and that there was enough information in the alert (such as the fact that there was no short-term variability in the ASM time-series data) and the associated web page (such as the extremely large error box) for you to have made a productive evaluation of the situation.