Phase 2 Proposal Instructions for Cycle 10

Chapter4:
Solar System Targets List
[Solar_System_Targets]

In this chapter . . .

Target Number [Target_Number] Target Name [Target_Name] Target Description [Description] Target Position Target Position Level 1 [Level_1] Target Position Level 2 [Level_2] Target Position Level 3 [Level_3] Ephemeris Uncertainty [Ephem_Uncert] Acquisition Uncertainty [Acq_Uncert] Observing Windows [Window] Flux Data [Flux] Comments [Comments] Illustrations of Orbital Longitude Examples of Target List Blocks

 

Tables and Figures

Table4.1: Solar System Standard Targets

Table4.2: Target Description Keywords

Table4.3: Positional Parameters for TYPE = COMET

Table4.4: Positional Parameters for TYPE = ASTEROID

Table4.5: Parameters for TYPE = PGRAPHIC

Table4.6: Parameters for TYPE = POS_ANGLE

Table4.7: Parameters for TYPE = MAGNETO

Table4.8: Parameters for TYPE = TORUS

Table4.9: Parameters for TYPE = SAT

Table4.10: Keywords for Observing Windows

Table4.11: Operators for Observing Windows

Table4.12: Formats for Specification of Target Flux Data

Figure 4.1: Orbital Longitude for Satellites

Figure 4.2: Orbital Longitude for Planets

HST is able to point at and track solar system targets with sub-arcsecond accuracy. In order for target acquisition and tracking to succeed, planetary observers must specify positions for their targets in a precise and unambiguous manner. Therefore, it is imperative that the Solar System Target List (SSTL) be carefully and correctly completed. This section explains how to fill out the SSTL for any solar system target.

Ephemerides are generated using fundamental ephemeris information from NASAÕs Jet Propulsion Laboratory (JPL). Ephemerides can be generated for all known types of solar system targets, including planets, satellites, comets, asteroids, surface features on planets and satellites, and offset positions with respect to the centers of all the above bodies. The following instructions demonstrate how to define solar system targets in a way that allows accurate ephemeris generation.

The body-axes definitions, body dimensions, directions of rotation poles, rotation rates, and the definitions of cartographic coordinates used by STScI are normally identical to the values adopted in the report of the ÒIAU Working Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites: 1982Ó (Davies, M.E., et al., Celestial Mechanics, 29, 309-321, 1983). In a few instances, the latter data have been updated due to new results obtained from the flyby spacecraft. Also, some new bodies have been added which were unknown at the time of the IAU report. For Jupiter and Saturn, the lambda(III) coordinate system is assumed, but lambda(I) or lambda(II) can be used. For Uranus and Neptune, coordinates follow the ÒReport of the IAU/IAG/COSPAR Working Group on Cartographic Coordinates and Rotation Rates of the Planets and SatellitesÓ (Celestial Mechanics and Dynamic Astronomy, 46, 197, 1989). If you need further information on these, please contact your Program Coordinator.

One exception exists to the requirements outlined above. Observers for solar system Targets of Opportunity (e.g. a ÒnewÓ comet or asteroid, a solar-wind disturbance reaching the Jovian magnetosphere, etc.), should complete the Generic Target List (See "Generic Targets List [Generic_Targets]" in Chapter 3.) and the Visit and Exposure Specifications (to the extent possible) in time for the Phase II deadline. If and when a suitable target appears, the proposer must complete the Solar System Target List and update the Visit and Exposure Specifications. No target can be observed until the complete Phase II information is provided.

In this chapter, each heading has a description followed by a keyword in square brackets (e.g., Target Number [Target_Number]). The keyword must be used in your RPS2 form. Elsewhere, items in boldface (e.g., RA-OFF) show words or phrases to be used directly as RPS2 entries. Items in brackets (e.g., <value>) show entries you are to provide. Parameters listed in square brackets (e.g., [A1 = <value>]) are optional, whereas those not in square brackets are required.