###Bright Object Protection### * What are the maximum allowable count rates? The limiting magnitudes with SBC modes are discussed and presented in ISR ACS-99-07. For practical considerations, a GO needs to remember that damage begins at ~200x (6 mag.) brighter than the limits provided in the first row of Table 3 of this ISR. For the general field, a GO observation will automatically pass screening if there are no stars within 6 mag. of the limits in the first row. If brighter stars are present, the GO will be asked to change targets, or select another filter, or provide UV flux information for the offending stars. If these remedies are not available, ST may provide color measurements of the offending stars. GOs are encouraged to read carefully the above mentioned ISR and Cycle 10/11 Call for Proposal instructions. The Exposure Time Calculators will issue a warning when global and local limits are reached by an exposure. * What information do I need to supply to my CS to allow him/her to verify that my target is safe? A GO will be asked to provide magnitude and color information for imaging observations and flux information for spectroscopic observations. Additional information (e.g. UV flux) may be requested, should bright object limits issues exist.