HST Phase 2 Target Coordinate Instructions
The HST reference frame is defined by the HST Guide Star Catalog (GSC) that STScI has created. For observations that require accurate coordinates, such as those using the spectrographs which have small apertures, it is very important that you provide positions derived in the same reference frame as the original GSC plate material. Except in special cases, you do not need to provide this level of sub-arcsecond accuracy for imaging observations.
Please note that the northern hemisphere of the publically available Digitised Sky Survey CDROMs was NOT USED for the construction of the GSC because of the proper motion effects. These plates should NOT BE USED when accurate coordinates are required.
Field |
Region Name |
GS PLATE ID |
LMC |
XX001 |
06B0 |
SMC |
XX002 |
06B1 |
M31 |
XX005 |
0738 |
Check with your Program Coordinator for more details and/or exceptions