Appendix: Additional Observing Guidelines

Definition of Science Observing Time

For proposals requesting new observations, APT calculates the Science Time and the Execution Time based on the survey plan specified in APT. The Science Time is the amount of time the instrument spends on sky, observing targets, while the Execution Time takes into account internal overheads, and the Charged Time includes all the instrument and observatory overheads needed to support the science observations. For the number of hours requested on the RTPS proposal submission page, the proposer should report the Charged Time in hours quoted from the APT. See the RDox documentation on APT for more details.

Duplicate Observations

To ensure the most efficient use of the Roman Space Telescope, new observations that duplicate those already approved for execution will need to be justified. 

Definitions

Observations will be flagged as a potential duplicate if the sensitivity for the proposed observations, in the same optical element, is within a factor of three of the sensitivity of the existing observations and the areas on the sky covered by the two programs overlap by more than 50%.

Examples of observations that may be approved include: synoptic observations of time-variable phenomena and second-epoch (or later) observations searching for transient phenomena. In this case, a single observation of the same area of the sky will not disallow the time-series observations. On the other hand, if the time-series observations occur before the single observation, it will disallow the single observation (since the objectives of the single observation could be achieved by using data from the time-series observations). Examples of proposed investigations that are unlikely to be approved include a large-area survey where excising (“cutting out”) a small area to avoid overlap with a previously cataloged observation is so inefficient that it increases the observing time for the affected observation. If a new candidate observation is less sensitive than a previously accepted observation and if it meets the area overlap criterion above, it will always be considered a duplicate since the science objective of the new program can be achieved using the deeper observation.

Policies on Duplication

Any newly proposed observation meeting the criteria listed above will be deemed a potential duplicate observation. If inspection reveals the new observation to be a duplicate without a scientific justification, the proposed observation will (in general) be forbidden. Observations that are deemed to be acceptable duplicates of observations defined above will be noted by the SSC, and this information will be provided to the Time Allocation Committee (TAC) for evaluation and adjudication, and they will make a recommendation to the Roman Selecting Official.

Activation of Targets of Opportunity (ToO) Request

Approved ToO programs will receive instructions on the activation process following the program selection. Following the activation request, the Science Centers will ascertain the impact of the ToO observations on the mission schedule and will work with the PI and the PSO to resolve any conflicts and determine a course of action.

Data Rights

All Roman data is publicly available in the MAST archive with no proprietary period.

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