! $Id: 6322,v 7.1 1995/08/04 00:38:14 pepsa Exp $
Proposal_Information                    ! Section 4
              Title: Weak interstellar lines in the spectrum of Xi Persei 
  Proposal_Category: GTO/HRS
Scientific_Category: Interstellar Medium
              Cycle: 5

Investigators
            PI_Name:     Dennis Ebbets
     PI_Institution:     Ball Aerospace and Communications Group        

           CoI_Name:     Jason Cardelli
    CoI_Institution:     Villanova University 
            Contact:     N          ! Y or N (designate at most one contact)


                                                
Abstract:                               ! Free format text (clear and concise)

This proposal defines observations of two wavelengths in the interstellar
spectrum of Xi Persei. Both are made with Echelle B, and will achieve
signal to noise ratios near 500 per data point. The spectral regions include
weak interstellar absorption lines of C II and Si II that have not been 
detected in GHRS data with lower resolution and signal to noise.

Questions                               ! Free format text (clear and concise)


    Observing_Description:     Lines 10 - 20 define a standard GHRS onboard
    target acquisition, with an RTB search and double locate in the Large 
    Science Aperture. With an integration period (step time) of 0.2 sec, 
    the counter will not saturate even with a bright star and mirror A2. The
    spectra will be taken with the star in the 2.0 LSA.
    
    Lines 100 - 110 and 200 - 210 accumulate the spectra
    of the two wavelength regions. Each region is observed at two independent
    central wavelengths, with a standard four step FP-SPLIT sequence at each.
    The eight subexposures will each accumulate enough counts for a S/N = 180,
    and will reach approximately 500 when fully merged. We expect to detect
    lines as weak as 0.1 milli-Angstrom equivalent width.

     
Real_Time_Justification:  No real-time resources are requested.

Calibration_Justification:  No special calibrations are requested.

Additional_Comments: 

Fixed_Targets                           ! Section 5.1
  Target_Number: 1
    Target_Name: HD24912
Alternate_Names: XI-PER
    Description: ISM, Absorption Line System          
       Position:  RA=3H 58M 57.8S +/- 0.5S,
                  DEC=35D 47' 28.0" +/- 0.5",
        Equinox:  2000            
           Flux:  V=4.04, F-CONT(2330)=3.3E-10  
       Comments:          




Visits                                  ! Section 6
      Visit_Number:  1
Visit_Requirements:                     ! Section 7.1
  On_Hold_Comments:
    Visit_Comments:

     Exposure_Number: 10                  ! Section 6.5
         Target_Name: HD24912
              Config: HRS       
              Opmode: ACQ           
            Aperture: 2.0            
          Sp_Element: MIRROR-A2          
          Wavelength:           
 Optional_Parameters: SEARCH-SIZE=5, BRIGHT=RETURN
Number_of_Iterations: 1
   Time_Per_Exposure: 5S          
Special_Requirements: ONBOARD ACQ FOR 20     
            Comments: STEP-TIME=0.2S                      
                      
!  
     Exposure_Number: 20                  ! Section 6.5
         Target_Name: HD24912
              Config: HRS              
              Opmode: ACQ/PEAKUP              
            Aperture: 2.0            
          Sp_Element: MIRROR-A2         
          Wavelength:           
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure: 20.4S           
Special_Requirements: ONBOARD ACQ FOR 100-210   
            Comments: STEP-TIME=0.2S                      

!
     Exposure_Number: 100                  ! Section 6.5
         Target_Name: HD24912
              Config: HRS             
              Opmode: ACCUM              
            Aperture: 2.0            
          Sp_Element: ECH-B24          
          Wavelength: 2325.0           !C II
 Optional_Parameters: STEP-PATT=6,
                      FP-SPLIT=STD,
Number_of_Iterations: 1
   Time_Per_Exposure: 1209.6S 
Special_Requirements:                   ! Section 7.2
            Comments: STEP-TIME=0.2S                      


!
     Exposure_Number: 110                  ! Section 6.5
         Target_Name: HD24912
              Config: HRS             
              Opmode: ACCUM              
            Aperture: 2.0            
          Sp_Element: ECH-B24          
          Wavelength: 2325.8           !C II
 Optional_Parameters: STEP-PATT=6,
                      FP-SPLIT=STD,
Number_of_Iterations: 1
   Time_Per_Exposure: 1209.6S               
Special_Requirements:                   ! Section 7.2
            Comments: STEP-TIME=0.2S                      


!
     Exposure_Number: 200                  ! Section 6.5
         Target_Name: HD24912
              Config: HRS             
              Opmode: ACCUM              
            Aperture: 2.0            
          Sp_Element: ECH-B24          
          Wavelength: 2335.0           !Si II
 Optional_Parameters: STEP-PATT=6,
                      FP-SPLIT=STD,
Number_of_Iterations: 1
   Time_Per_Exposure: 1209.6S    
Special_Requirements:                   ! Section 7.2
            Comments: STEP-TIME=0.2S                      

!
     Exposure_Number: 210                  ! Section 6.5
         Target_Name: HD24912
              Config: HRS             
              Opmode: ACCUM              
            Aperture: 2.0            
          Sp_Element: ECH-B24          
          Wavelength: 2335.8           !Si II
 Optional_Parameters: STEP-PATT=6,
                      FP-SPLIT=STD,
Number_of_Iterations: 1
   Time_Per_Exposure: 1209.6S      
Special_Requirements:                   ! Section 7.2
            Comments: STEP-TIME=0.2S                      


Data_Distribution 

         Medium:        8MM  
Blocking_Factor:        10                               
        Ship_To:        GHRS IDT at Goddard Space Flight Center
       Ship_Via:        GHRS team will pick up data at STScI
Recipient_Email:        hrsake@hrs.gsfc.nasa.gov