The Rapid Response Mode

This page provides information about the Phase 2 preparation of approved programs that require the use of the Rapid Response Mode (RRM), and specifies the guidelines for activation.

Rapid Response Mode: Introduction

The RRM at the VLT allows the automatic trigger of observations of transient phenomena requiring almost immediate follow-up, such as gamma-ray bursts, novae, or supernovae. It basically works as follows:

  • An observation trigger signal is sent via an ASCII file to the ftp server, requesting the execution of a specific Observation Block (OB).
  • A program at the telescope is continuously monitoring the dedicated ftp directory.
  • When a valid trigger signal is found in the ftp directory the on-going observation is ended, the telescope automatically presets to the coordinates specified in the ftp file, and performs the requested observations as specified in the trigger signal.

Note: Please consider that RRM OBs, which use a special template, can be triggered only through the RRM procedure. Any OBs intended to follow a RRM trigger, including those intended to be executed immediately after the RRM OB, must be submitted as normal ToO OBs.

RRM Phase 2 Preparations

  • Once a RRM proposal is approved, a complete Phase 2 package (Observation Blocks and Readme file) needs to be prepared and submitted to ESO following the standard Phase 2 preparation procedures. In particular, please note that the deadline for the submission of the Phase 2 package applies for RRM runs as well.
  • The names of OBs for execution in RRM mode must be preceded by the RRM_ prefix (e.g. RRM_grb346+580_3x600s). They should not contain any spaces or special characters, but only letters, digits, dashes, plus signs and/or underscores. The name of each RRM OB in a given run should be unique, multiple RRM OBs with the same name will prevent their triggering.
  • RRM OBs should not be organized in scheduling containers, but rather be loose OBs. If they are in scheduling containers it will not be possible to trigger them.
  • Once an activation has been successfully triggered, the OB executed cannot be used for another activation.
  • Besides the RRM OBs, the users should also prepare normal ToO OBs in case non-RRM observations are required: for instance, for follow-up of the RRM activation (since with RRM only one OB can be activated), or if observations of the target are desired when the 4-hour RRM deadline has passed (see below). These ToO OBs should be preparated and submitted during Phase-2 in a separated run from the RRM one.
  • The ESO User Support Department verifies the submitted material. The p2pp-id used to create the activation file as well as the host name, username, and password used for uploading it
    will be communicated by Paranal to the Principal Investigator of the programme shortly before the start of the period or in due time in the case of a DDT programme.

Information regarding RRM Activation

  • To activate the RRM, an ASCII file must be received at the dedicated ftp server in Garching with the following characteristics:
    • Its name must be the same as that of the OB that needs to be executed, preceded by a string of the generic form [instrument]_[p2pp ID]_[OB] (e.g. UVES_5291_RRM_grb346+580_3x600s). Your p2pp ID is not your User Portal username, but rather a number which will be supplied to you by the Observatory before the start of the new Observing Period (or in due time if yours is a DDT programme).
    • Its content must be a single line with the J2000.0 coordinates of the target. The format is for the right ascension, sddmmss.s for the declination (e.g. 004727.32 -251738.3)
  • The activation file must be uploaded to the relevant instrument sub-directory, such as:
    • ~/UVES/ for UVES activations,
    • ~/FORS2/ for FORS2 activations,
    • ~/SINFONI/ for SINFONI activations,
    • ~/HAWKI/ for HAWK-I activations,
    • ~/XSHOOTER/ for X-SHOOTER activations (Note that XSHOOTER must be used as [instrument] for the file name.),
    • ~/MUSE/ for MUSE activations
  • Along with the RRM trigger signal, accompanying RRM information, including a finding chart, must be sent to Paranal using established Target of Opportunity (ToO) procedures. For RRM activations only, an email template, can be used as a substitute for filling out the ToO activation webpage:

    Do not attach the finding chart to the email, but include a link to a webpage that contains the finding chart in the comments section. For the time being, a simple activation email (to either for UT1, for UT2, for UT3 or for UT4) with the finding chart attached will also be accepted.

    Please note: As of 9 October 2015 we are temporarily experiencing problems with the automated processing of e-mails to so we strongly urge PIs to send e-mail to the telescope account in addition to sending the RRM form to Even better is to use directly the Paranal ToO web form to provide the necessary information.

  • Only requests from the end of evening nautical twilight to the beginning of morning nautical twilight (i.e., received when the Sun is more than 12 degrees below the horizon) will activate the RRM.
  • Any RRM activation arriving outside the time interval noted in the previous point will be discarded with no trigger counted.
  • It is the responsibility of the activators to ensure that the target is observable, bright enough, and easy to identify by the night astronomer.
  • Any successful activation will be counted as an RRM trigger, whether the requested observations could be successfully performed or not.
  • RRM activations will be accepted during both Service and Visitor Mode runs: they have overriding priority over other observations. The only exceptions are cases in which the OPC have granted a 'protected status' for Visitor Mode observations of events with exceptional characteristics.ToO observations immediately following the RRM ones have the same override status over Visitor Mode.
  • The requested instrument must be already in operation. Due to the need to provide an immediate response to the event switch between telescope foci is not possible. RRMs arriving for an instrument that is not in operation will be discarded with no trigger counted.
  • An RRM trigger is a special ToO trigger that can only be activated up to 4 hours after an event. After this deadline observations should be requested through normal ToO triggers.
  • It is possible that the RRM status does not allow an alert to be triggered, but that ToO observations are possible during the same night (e.g. due to a focus switch to the relevant instrument). If desired, these observations should be requested through the normal Target of Opportunity (ToO) procedures, and the proper ToO OBs must have been prepared. The ToO OBs should be preparated and submitted during Phase-2 in a separated run from the RRM one. These ToO observations, if successful, will be counted as a RRM trigger.
  • Any desired immediate follow-up observations of a successful RRM trigger must be requested through the normal ToO procedure, since only one OB can be executed as RRM. Such a ToO request can be already specified in the RRM alert email, or in a separate ToO request. Also in this case, ToO OBs must have been prepared before the Phase 2 deadline for this to be possible and should have been submitted in a separated run from the RRM one. The execution of such follow-up observations cannot be guaranteed.
  • As of Period 90 (1 October 2012) all RRM data (including GTO) will be accessible by everyone after the proprietary protection has expired. During the proprietary period the data will only be accessible to the corresponding PIs and their data delegates.
  • RRM and ToO data will be made available immediately to the PIs and their data delegates through the ESO archive via the User Portal.
  • For all RRM programmes the default (12 months) proprietary period will apply for the rest of the world, unless a shorter period has been specified in the Phase 1 proposal.
  • Any intentional misuse of the RRM (e.g. for the observation of events unrelated to the science case in the approved proposal or for late-time follow-up not justifying the use of the RRM) will result in the cancellation of the program in question.

Time accounting

  • The time accounting is performed in the same way as for normal ToOs; if a program has used up all its hours, irrespective of the number of (RRM) triggers executed, no more triggers will be accepted.
  • The time used by a RRM is counted from the start of the OB that was interrupted until the start of the first OB after the RRM OB.

Checking the status of the RRM system and of activation requests

The state of the RRM process, and the result of an activation, can be followed on one of these webpages:

The delay is of the order of a few minutes. Requests will only be executed if the RRM state is ONLINE.

Instrument selector

This page is valid for all instruments