! Proposal 6613, submission 3
! PI: Michael F. A'Hearn
! Received Tue Feb 27 08:06:32 EST 1996
! From: storrs@stsci.edu
Proposal_Information                           ! Section 4
              Title:  The Origin of C_2 in Comets
  Proposal_Category:  GO
Scientific_Category:  SOLAR SYSTEM
             Cycle:    6

Investigators
     PI_name:         Michael F. A'Hearn
     PI_Institution:  University of Maryland

          CoI_Name:   Claude Arpigny
   CoI_Institution:   Institut d'Astrophysique
           Contact:             ! Y or N (designate at most one contact)

          CoI_Name:   Paul D. Feldman
   CoI_Institution:   The Johns Hopkins University
           Contact:             ! Y or N (designate at most one contact)

          CoI_Name:   William M. Jackson
   CoI_Institution:   University of California - Davis
           Contact:             ! Y or N (designate at most one contact)

          CoI_Name:   Harold A. Weaver
   CoI_Institution:   Applied Research Corp.
           Contact:             ! Y or N (designate at most one contact)


Abstract:                                ! Free format text (please update)
    We propose to observe any comet satisfying the constraint Q(
    C_2) > 1.4 * 10^26 s^-1 at r_H = 1 AU to map the Mulliken and
    Swan bands of C_2.  The relative intensities of the singlets
    and triplets and the excitation temperatures will be mapped as
    a function of distance from the nucleus.  This will constrain
    the presently unknown formation mechanism for producing C_2
    and thus the identity of its parent.  It will also constrain
    the rate for intercombination (singlet-triplet) transitions
    and thus provide crucial information required for the detailed
    study of the resonance fluorescence of C_2.

Questions                       ! Free format text (please update)

     Observing_Description:
            We propose to use FOS with the G270H grating for the Mulliken
         bands and with the G570H grating for the Swan bands (only the
         Delta v = +2 sequence is not covered by this grating).  The
         aperture will be the 1.0 aperture (circular, diameter = 0.86 
	 arcsec) The offsets are nominally at  0, 400, 800, 1600, and 
	 3200 km sunward.  On April 2.0, the geocentric distance is
	 such that these offsets correspond to 0, 2, 4, 8, and 16 arcsec.
	 A 25% change in the offsets in km is acceptable as long as the
	 actual offsets are known.  In order to not be subject to large
         errors due to variability of the comet, the G270H and G570H
         observations will be interleaved in pairs at each offset, one
         orbit each for the first three positions and 2 orbits each
         for the last two positions (the two largest offsets).  The 
	 various spatial positions will all be observed in a single 
	 visit. Sufficient signal-to-noise ratio will be achieved with 
	 G570H in several seconds so we have adopted a nominal exposure 
	 time of 1 minute for all G570H exposures with all remaining 
	 time to be devoted to the G270H exposures.
	    The ephemeris of the comet is very uncertain at this time.
         Even at the time of observation the ephemeris of the comet will
	 not be sufficient for putting the comet in the aperture of FOS.
	 An image with WFPC and real-time analaysis with uplink of an
	 offset will almost certainly be needed to load an offset from
	 the ephemeris.  We assume that this program will be executed at
	 essentially the same time as the program of J. Brandt or that
	 of H. Weaver, both of whom wish to observe at nearly the same
	 time and both of whom have WFPC2 images as part of their programs.
	 Images from their programs can be used for the Real-Time Analysis, 
	 with only the need for an uplinked offset in our program.  In 
	 addition to the problem of updating the ephemeris, there is the 
	 problem of placing the target precisely in the 1.0 arcsec aperture 
	 of FOS.  With the spatial scale available for this comet, a guide 
	 star uncertainty of 0.8 arcsec is undesirable but tolerable, 
	 provided that we know precisely where the target is relative to 
	 the FOS aperture, at least for the positions on and nearest the 
	 nucleus (for the larger offsets, the 0.8 arcsec uncertainty is 
	 not important).  We have therefore also requested an FOS IMAGE
	 to map the aperture at the start of each of the first two orbits 
	 in order to determine the initial position accurately.  We would
	 prefer an ACQ image but there is some chance taht use of the mirror
	 instead of a grating would overload the sensor and trigger a
	 safing.

	 Each orbit in the sequence is treated as a separate visit in order
	 to allow us to use different ephemeris corrections for each orbit
	 and to force a guide star acquisition at the start of each orbit.
	 Nevertheless, we wish the entire sequence to be carried out in
	 successive orbits.

   Real_Time_Justification:


Calibration_Justification:              ! Move appropriate text from Real_Time_Justification

      Additional_Comments:


!Fixed_Targets                           ! Section 5.1
!  Target_Number:
!    Target_Name:
!Alternate_Names:
!    Description:
!       Position:                        ! Most common specification format is
                                        ! RA=0H 0M 0.00S +/- 0S,
                                        ! DEC=0D 0' 0.0" +/- 0",
                                        ! PLATE-ID=0000
!        Equinox:
!        RV_or_Z:
!          RA_PM:                        ! Units are seconds of time per year
!         Dec_PM:                        ! Units are seconds of arc per year
!          Epoch:
!Annual_Parallax:
!           Flux:                        ! Include at least V and B-V
!       Comments:


Solar_System_Targets                    ! Section 5.2
  Target_Number:01
    Target_Name:C-Hyakutake-Off0
    Description:COMET Hyakutake
        Level_1:TYPE=COMET,              ! Satellite of Sun
		Q=0.23015585,
		E=0.99997350,
		I=124.886015,
		O=188.060838,
		W=130.184765,
		T=01-MAY-96:09:51:47,
		EPOCH=03-MAY-96,
		EQUINOX=J2000
        Level_2:                        ! Satellite of Level_1
        Level_3:                        ! Satellite of Level_2
   Ephem_Uncert: 600S                  ! Needed for REQ EPHEM CORR sp req
     Acq_Uncert: 20"                    ! Needed for SAVE and USE OFFSET sp reqs
         Window: RANGE EARTH C-Hyakutake-Off0 LT 0.3
           Flux: V=2, B-V=0.7                        ! Include at least V and B-V
       Comments:

  Target_Number:02
    Target_Name:C-Hyakutake-Off2
    Description: OFFSET COMET Hyakutake
        Level_1:TYPE=COMET,              ! Satellite of Sun
		Q=0.23015585,
		E=0.99997350,
		I=124.886015,
		O=188.060838,
		W=130.184765,
		T=01-MAY-96:09:51:47,
		EPOCH=03-MAY-96,
		EQUINOX=J2000

        Level_2:TYPE=POS_ANGLE,          ! Satellite of Level_1
		RAD=2.0,
		REF=SUN,
		ANG=0.0
        Level_3:                        ! Satellite of Level_2
   Ephem_Uncert: 600S                  ! Needed for REQ EPHEM CORR sp req
     Acq_Uncert: 20"                    ! Needed for SAVE and USE OFFSET sp reqs
         Window: RANGE EARTH C-Hyakutake-Off2 LT 0.3
           Flux:  V=2, B-V=0.7           ! Include at least V and B-V
       Comments:

  Target_Number:03
    Target_Name:C-Hyakutake-Off4
    Description:OFFSET COMET Hyakutake
        Level_1:TYPE=COMET,              ! Satellite of Sun
		Q=0.23015585,
		E=0.99997350,
		I=124.886015,
		O=188.060838,
		W=130.184765,
		T=01-MAY-96:09:51:47,
		EPOCH=03-MAY-96,
		EQUINOX=J2000

        Level_2:TYPE=POS_ANGLE,          ! Satellite of Level_1
		RAD=4.0,
		REF=SUN,
		ANG=0.0
        Level_3:                        ! Satellite of Level_2
   Ephem_Uncert: 600S                  ! Needed for REQ EPHEM CORR sp req
     Acq_Uncert: 20"                    ! Needed for SAVE and USE OFFSET sp reqs
         Window: RANGE EARTH C-Hyakutake-Off4 LT 0.3
           Flux: V=2, B-V=0.7           ! Include at least V and B-V
       Comments:

  Target_Number:04
    Target_Name:C-Hyakutake-Off8
    Description:OFFSET COMET Hyakutake
        Level_1:TYPE=COMET,              ! Satellite of Sun
		Q=0.23015585,
		E=0.99997350,
		I=124.886015,
		O=188.060838,
		W=130.184765,
		T=01-MAY-96:09:51:47,
		EPOCH=03-MAY-96,
		EQUINOX=J2000

        Level_2:TYPE=POS_ANGLE,          ! Satellite of Level_1
		RAD=8.0,
		REF=SUN,
		ANG=0.0
        Level_3:                        ! Satellite of Level_2
   Ephem_Uncert: 600S                  ! Needed for REQ EPHEM CORR sp req
     Acq_Uncert: 20"                 ! Needed for SAVE and USE OFFSET sp reqs
         Window: RANGE EARTH C-Hyakutake-Off8 LT 0.3
           Flux: V=2, B-V=0.7          ! Include at least V and B-V
       Comments:

  Target_Number:05
    Target_Name:C-Hyakutake-Off16
    Description:OFFSET COMET Hyakutake
        Level_1:TYPE=COMET,              ! Satellite of Sun
		Q=0.23015585,
		E=0.99997350,
		I=124.886015,
		O=188.060838,
		W=130.184765,
		T=01-MAY-96:09:51:47,
		EPOCH=03-MAY-96,
		EQUINOX=J2000

        Level_2:TYPE=POS_ANGLE,          ! Satellite of Level_1
		RAD=16.0,
		REF=SUN,
		ANG=0.0
        Level_3:                        ! Satellite of Level_2
   Ephem_Uncert: 600S                  ! Needed for REQ EPHEM CORR sp req
     Acq_Uncert: 20"                    ! Needed for SAVE and USE OFFSET sp reqs
         Window: RANGE EARTH C-Hyakutake-Off16 LT 0.3
           Flux: V=2, B-V=0.7            ! Include at least V and B-V
       Comments:

!Generic_Targets                         ! Section 5.3
!  Target_Number:
!    Target_Name:
!    Description:
!       Criteria:
!           Flux:
!       Comments:


!Scan_Data                               ! Appendix B
!    Scan_Number:
!       FGS_Scan:
!  Cont_or_Dwell:
!   Dwell_Points:
!     Dwell_Secs:
!     Scan_Width:
!    Scan_Length:
!    Sides_Angle:
!   Number_Lines:
!      Scan_Rate:
!  First_Line_PA:
!     Scan_Frame:
!  Length_Offset:
!   Width_Offset:


! This is a template for a single visit containing a single exposure
! Repeat exposure and visit blocks as needed

Visits                                  ! Section 6
      Visit_Number:10
Visit_Requirements: SEQ 10-70 WITHIN 960M                     ! Section 7.1
		    BETWEEN 01-APR-96 AND 03-APR-96
          	    GUIDing TOLerance 2"
		    SCHED 100%

! Uncomment or copy visit level special requirements needed
! Most of these requirements (including ORIENT) will limit scheduling

  On_Hold_Comments:
    Visit_Comments:I assume that one of the other ToO programs will
    take an image shortly prior to the start of this program and that
    this image will be used to generate an ephemeris correction to
    be uplinked for this program.  Use of G570H followed by G270H is
    chosen for pointing reasons but if time to rotate grating wheel the
    long-way round is truly excessive, opposite order can be considered.
    This visit should be completed in one orbit.

     Exposure_Number: 10                  ! Section 6.5
         Target_Name: C-Hyakutake-Off0
              Config: FOS/RD
              Opmode: IMAGE
            Aperture: 4.3
          Sp_Element: G570H
 Optional_Parameters: Y-SIZE=5
		      Y-SPACE=128
		      COMB=YES
		      SUB-STEP=4
Number_of_Iterations: 1
   Time_Per_Exposure: 20S
Special_Requirements: REQ EPHEM CORR HYAKU1
		      SEQ 10-12 NON-INT
            Comments: Assumes V=10.3 for the comet in a 0.7" diameter FOV


     Exposure_Number:11                 ! Section 6.5
         Target_Name:C-Hyakutake-Off0
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G570H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:60S
Special_Requirements: REQuires EPHEMeris CORRection HYAKU1
                 ! Section 7.2

     Exposure_Number:12                 ! Section 6.5
         Target_Name:C-Hyakutake-Off0
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G270H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:20M
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  EXPAND
	  END ORBIT
	  MIN DUR 18M


      Visit_Number: 20
Visit_Requirements:                      ! Section 7.1
          GUIDing TOLerance 2"
	  SCHED 100%


     Exposure_Number: 20                  ! Section 6.5
         Target_Name: C-Hyakutake-Off2
              Config: FOS/RD
              Opmode: IMAGE
            Aperture: 4.3
          Sp_Element: G570H 
 Optional_Parameters: Y-SIZE=5
		      Y-SPACE=128
		      COMB=YES
		      SUB-STEP=4
Number_of_Iterations: 1
   Time_Per_Exposure: 20S
Special_Requirements: REQ EPHEM CORR HYAKU1
          SEQuence 20-22 NON-INTerruptible
            Comments: Assumes V=10.3 for the comet in a 0.7" diameter FOV

     Exposure_Number:21                 ! Section 6.5
         Target_Name:C-Hyakutake-Off2
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G570H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:60S
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1

     Exposure_Number:22                 ! Section 6.5
         Target_Name:C-Hyakutake-Off2
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G270H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:20M
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  EXPAND
	  END ORBIT
	  MIN DUR 18M

      Visit_Number: 30
Visit_Requirements:                      ! Section 7.1
          GUIDing TOLerance 2"
	  SCHED 100%

     Exposure_Number:31                 ! Section 6.5
         Target_Name:C-Hyakutake-Off4
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G570H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:60S
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  SEQ 31-32 NON-INT

     Exposure_Number:32                 ! Section 6.5
         Target_Name:C-Hyakutake-Off4
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G270H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:24M
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  EXPAND
	  END ORBIT
	  MIN DUR 20M

      Visit_Number: 40
Visit_Requirements:                      ! Section 7.1
          GUIDing TOLerance 2"
	  SCHED 100%

     Exposure_Number:41                 ! Section 6.5
         Target_Name:C-Hyakutake-Off8
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G570H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:60S
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  SEQ 41-42 NON-INT

     Exposure_Number:42                 ! Section 6.5
         Target_Name:C-Hyakutake-Off8
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G270H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:24M
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  END ORBIT
	  MIN DUR 20M

      Visit_Number: 50
Visit_Requirements:                      ! Section 7.1
          GUIDing TOLerance 2"
	  SCHED 100%

     Exposure_Number:51                 ! Section 6.5
         Target_Name:C-Hyakutake-Off8
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G570H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:60S
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  SEQ 51-52 NON-INT

     Exposure_Number:52                 ! Section 6.5
         Target_Name:C-Hyakutake-Off8
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G270H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:24M
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  EXPAND
	  END ORBIT
	  MIN DUR 20M

      Visit_Number: 60
Visit_Requirements:                     ! Section 7.1
          GUIDing TOLerance 2"
	  SCHED 100%

     Exposure_Number:61                 ! Section 6.5
         Target_Name:C-Hyakutake-Off16
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G570H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:60S
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  SEQ 61-62 NON-INT

     Exposure_Number:62                 ! Section 6.5
         Target_Name:C-Hyakutake-Off16
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G270H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:24M
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  EXPAND
	  END ORBIT
	  MIN DUR 20M

      Visit_Number: 70
Visit_Requirements:                      ! Section 7.1
          GUIDing TOLerance 2"
	  SCHED 100%

     Exposure_Number:71                 ! Section 6.5
         Target_Name:C-Hyakutake-Off16
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G570H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:60S
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  SEQ 71-72 NON-INT

     Exposure_Number:72                 ! Section 6.5
         Target_Name:C-Hyakutake-Off16
              Config:FOS/RD
              Opmode:ACCUM
            Aperture:1.0
          Sp_Element:G270H
          Wavelength:
 Optional_Parameters:
Number_of_Iterations: 1
   Time_Per_Exposure:24M
Special_Requirements:                   ! Section 7.2
          REQuires EPHEMeris CORRection HYAKU1
	  EXPAND
	  END ORBIT
	  MIN DUR 20M
            Comments:


Data_Distribution                       ! Defaults indicated; change if desired

         Medium:        8MM             ! 8MM or 6250BPI or 1600BPI
Blocking_Factor:        10              ! 10 or 1
                                        ! Only astronomers with very old 9-
                                        ! track tape drives should consider
                                        ! a blocking factor of 1

        Ship_To:        PI_Address      ! STSCI or PI_Address or <free-text>
                                        ! PI Address from Phase I is:
                                        !
                                                 !  Department of Astronomy
                                                 !  College Park
                                                 !  20742-2421
                                        !
                                        !
       Ship_Via:        UPS             ! UPS (2-day) or OVERNIGHT
                                        ! Overnight shipping done at PI expense

Recipient_Email:                        ! Needed if Ship_To: is not PI_Address
                                        ! <free-text>

! Let us know what you think of this template and software!
! Please send a list of your likes and dislikes to your Program Coordinator