30 January 1998

                        FOS CLOSEOUT FLUX CALIBRATION UPDATE

        The FOS Closeout Flux Calibration includes new deliveries of ALL 
post-COSTAR AIS reference files and three of the four supporting tables.  
A single pre-COSTAR reference table is updated.  
        Table 1 below lists post-COSTAR AIS reference files and 
tables and Table 2 lists pre-COSTAR AIS files and tables which are available
online at STScI via StarView or anonymous ftp from ftp.stsci.edu/cdbs/cdbs2/yref.   
        A detailed discussion of the advantages of re-calibration with the AIS 
method is provided in the third edition of the HST Data Handbook.  Simply 
put, all FOS observations benefit from this re-calibration.

  =============================================================

                     TABLE 1    

 Listing of "AISHFILE" required reference files for 

                   POST-Costar

        AIS Method FOS Flux Calibration

Detector   grating     header file      

FOS/BL   G130H (H13)  I1K1431SY.R8H     
FOS/BL   G190H (H19)  I1K1431TY.R8H   
FOS/BL   G270H (H27)  I1K14320Y.R8H
FOS/BL   G400H (H40)  I1K14321Y.R8H
FOS/BL   G570H (H57)  I1K14322Y.R8H
FOS/BL   G160L (L15)  I1K14323Y.R8H
FOS/BL   PRISM (PRI)  I1K14324Y.R8H

FOS/RD   G190H (H19)  I1K14325Y.R8H
FOS/RD   G270H (H27)  I1K14326Y.R8H             
FOS/RD   G400H (H40)  I1K14327Y.R8H             
FOS/RD   G570H (H57)  I1K14328Y.R8H             
FOS/RD   G780H (H78)  I1K14329Y.R8H             
FOS/RD   G160L (L15)  I1K1432AY.R8H             
FOS/RD   G650L (L65)  I1K1432BY.R8H             
FOS/RD   PRISM (PRI)  I1K1432CY.R8H

Also required FOR ALL DETECTORS AND GRATINGS are the 
following four tables (no other versions of the following 
tables are valid for POST-COSTAR analysis):

        FAD1554CY.CYA  

        I1N1816EY.CYB   

        I1N1816FY.CYC   

        I1N1816DY.CYD   

  =============================================================

                     TABLE 2    

 Listing of "AISHFILE" required reference files for 

                   PRE-Costar

        AIS Method FOS Flux Calibration

Detector   grating     header file      

FOS/BL   G130H (H13)  G2T1439KY.R8H   
FOS/BL   G190H (H19)  G2T1439LY.R8H   
FOS/BL   G270H (H27)  G2T1439NY.R8H   
FOS/BL   G400H (H40)  G2T1439OY.R8H   
FOS/BL   G160L (L15)  G2T1439PY.R8H   
FOS/BL   PRISM (PRI)  G2T1439QY.R8H   
FOS/BL   G570H (H57)  G2T1439RY.R8H   

FOS/RD   G190H (H19)  G2T14397Y.R8H   
FOS/RD   G270H (H27)  G2T14399Y.R8H   
FOS/RD   G400H (H40)  G2T1439BY.R8H   
FOS/RD   G570H (H57)  G2T1439CY.R8H   
FOS/RD   G780H (H78)  G2T1439EY.R8H   
FOS/RD   G160L (L15)  G2T1439GY.R8H   
FOS/RD   G650L (L65)  G2T1439HY.R8H   
FOS/RD   PRISM (PRI)  G2T1439JY.R8H   

Also REQUIRED FOR ALL DETECTORS AND GRATINGS are the 
following four tables (no other versions of the following 
tables are valid for PRE-COSTAR analysis):

         G310947PY.CYA   

         I1N1816GY.CYB   

         G3109483Y.CYC   

         G3109487Y.CYD   

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This is version 04 of this file listing and is current as of 30-JAN-1998.