HST Call for Proposals and HST Primer for Cycle 24

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8.15

Targets

8.15.1 Target Number

8.15.2 Target Name

8.15.3 Provisional Coordinates

8.15.4 V-Magnitude

8.15.5 Other Fluxes

Your proposal can include observations of fixed targets (i.e., all targets outside the solar system whose positions can be defined by specific celestial coordinates), generic targets (i.e., targets defined by certain general properties, rather than by specific coordinates), and solar-system targets (i.e., moving targets). Targets that have not yet been discovered or identified may generally be included only under special circumstances (see Section 4.1.5), and should be given generic target names.

GO Proposals must include a list of all targets. Snapshot Proposals need only include a representative subset of targets in the Phase I submission (see Section 3.3.3). For proposals with a large number of fixed targets, there is a capability to ingest a comma-separated text file with the appropriate target information. See the APT Phase I Roadmap (“Fill in the Target Information”) for details.

8.15.1 Target Number

Each target in your proposal will be assigned a unique number by APT. A different target must be defined when different coordinates or a different target description are required. Separate targets should be defined and listed if observations are planned at several points within an extended object. For example, acquiring spectra at three different locations within the Crab nebula requires each point to have its own target number, name and co-ordinates, such as CRAB1, CRAB2 and CRAB3. However, if you are proposing a large field mosaic with the same exposures at each point, you may define one target for the object. You should specify in the Description of Observations the exact number of fields you plan to observe.

8.15.2 Target Name

The target naming conventions for HST are defined in detail in Section 3.2 of the HST Phase II Proposal Instructions. Please adhere to these naming conventions throughout your proposal. For generic targets use a short text description either of the target location (e.g., RANDOM-FIELD) or of the target itself (e.g., NEXT-SUPERNOVA).

8.15.3 Provisional Coordinates

Supply the coordinates for fixed targets only. In Phase I, target positions with accuracies of ~1 arc minute are sufficient for the TAC and panel review (except in crowded fields where the identity of the target may be in question). However, in Phase II significantly more accurate coordinates will be required, and it is the responsibility of the proposers to provide these. See the STScI Phase II documentation for details.

8.15.4 V-Magnitude

A magnitude or flux should be specified for every target. Supply the V-magnitude for the entire target (galaxy, planet, etc.), if known. In the case of observations with ACS/SBC, STIS/MAMA, or COS, specify the V-magnitude of the brightest object in the field of view (this may not be the primary target). For variable targets, give the brightest V-magnitude expected during the observations. The configurations mentioned above have detectors with bright-object safety limits, and observations that violate those limits are infeasible. See Section 5.1 of the HST Primer, or the respective Instrument Handbook (see Section 1.4.4) for details. With the exception of the safety checks, this information is used only for scientific review, not for exposure-time calculations. It is not required to specify the V-magnitude or flux for generic targets.

8.15.5 Other Fluxes

For each target you should specify either a V-magnitude or another magnitude or flux. Supply the apparent total magnitude or flux in the relevant passband for the entire target (galaxy, planet, etc.), if known. For variable targets, give the brightest magnitude expected during the observations. This information is used only for scientific review, not for exposure-time calculations. The format is free text.