FAQ

• My run can be executed more efficiently if my OBs are executed one after another, skipping the acquisitions for the latter OBs. Why cannot I ask for such a procedure for service observing?

  Answer: There is no guarantee that user specified conditions will last long enough to complete any given OB sequence. Furthermore, there may be different priorities between programmes that have targets observable under similar RA range. Thus breaking down a sequence of OBs often improves overall operations efficiency by allowing the execution of OBs best matching the external conditions and scientific ranking. Therefore, to maintain the flexibility needed to adapt to changing observing conditions and to maximise operations efficiency, ESO requires that all Service Mode OBs be treated as independent observations with independent acquisitions. If the constraints change during the first hour of observation your OB will be repeated without any penalty or cost to your run. 

• Having to split my OBs to make them compliant with the rule that no Service Mode OBs could last longer than one hour implies much more execution overhead. Wouldn't it be more efficient to allow longer OBs?

  Answer: Experience has shown that longer OBs make Service Mode observing less efficient, rather than more. The reason is that, the longer an OB, the more likely it is that the external conditions go outside the acceptable range specified in the Constraint Set. Since OBs executed outside constraints must be rescheduled and re-executed, longer OBs imply not only a higher fraction of OBs to be re-executed, but also a larger amount of time wasted in the execution of OBs failed because of the degradation of external conditions.

  Still, some programs may have scientific reasons that require OBs longer than one hour to be scheduled. In such case, a waiver request justifying the need for a longer execution time must be submitted to ESO. This is done by selecting the Run in the Phase 2 preparation tool p2 (or p2ls for La Silla observing runs), and then selecting Waiver request form in the upper right. When sufficiently justified, these requests are accepted under the condition that the OB will be considered as executed within constraints even if the conditions degrade after the first hour of execution.

• Is it possible to monitor the progress of my program?

  Answer: Yes. Both the Run Progress Reports page and the Science Archive query form allow you to access updated information on the progress of your observations. In p2 it is now also possible to see the current status of OBs. More information about OB statuses visible in p2 is available here. It is also possible to subscribe to receive an email notification from the nightlog tool each time one of your OBs is executed. The subscription is managed through the "Subscribe to night reports" link in the upper right of the Overview of ESO Observing Runs page in User Portal. The Garching Night Log Tool (gNLT) can also be accessed through the gNLT overview page using your User Portal credentials.

• If my programme cannot be completed by the end of the Period, can I ask to have it carried over to the next one?

  Answer:If your programme obtained a Priority Class A and has not been completed by the end of the Period, it will be considered as a candidate for carryover to the next Period without you having to request it. In this case you will get a notification from User Support Department about the possibile carryover at the time the Call for Proposals for the next observing period is issued. This is not possible at present with Priority Class B or C programmes, which are terminated at the end of the Period regardless of their status of completion. Please see our page on the philosophy and scheduling of Service Mode programmes for more information. If you had a Class B or C Programme and you see that the end of the Period is approaching without it being near completion, you are strongly encouraged to resubmit it as a new observing proposal.

• How can I know precisely on what dates my Service Mode observations will be executed?

  Answer: A key feature of the flexible scheduling approach followed at the ESO Observatories is that Service Mode Programmes do not have definite dates assigned to them. Rather, they are executed according to the external observing conditions, some of which are unpredictable, like the sky transparency or the seeing. Only in this way it is possible to ensure that each of the many programmes approved every semester in Service Mode is executed under the conditions that are necessary for its scientific goals.

  The Principle Investigators and their Phase 2 and/or data delgate(s) can subscribe to receive e-mail notification whenever one of their OBs has been executed. To subscribe login to the (Garching Night Log Tool) gNLT overview page using your User Portal credentials.

• ESO has communicated me the allocation of time to my run, but only in class C. Is it worth it to prepare any Phase 2 material at all?

  Answer:Yes! ESO selects class C programmes from those that did not get a high enough rating to be above the time allocation cutoff line, but whose constraints made them schedulable under a very wide range of conditions (i.e., in intervals of bad seeing, with moon, or under poor sky transparency conditions). Higher rated runs normally have more stringent constraints and, when the conditions are below average, only class C runs may be executable. Due to the high pressure factor at ESO telescopes, the scientific quality of class C runs is normally still very high, and experience shows that Service Mode class C programmes, which would not have been scheduled in classical Visitor Mode, have produced very valuable scientific results.