Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2144c Report Date: 09-May-96:16:54 Version: ********** Check-in Date: ********** 1.Proposal Title: NEAR AND MID ANGLE SCATTERING MEASUREMENT TEST ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SV/OLT Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Christopher Burrows ST SCI USA (301) 338-4913 ------------------------------------------------------------------------------------ 7. Abstract Test Objective: Determine the effect of internal HST light scattering. Use spectroscopic measurements taken within a radius of approximately 25 arc seconds from a bright (V about 7) target star. The scattering may be due to dust particles or minute surface irregularities in the OTA mirror surfaces. Determine the spectral energy distribution by obtaining low resolution spectra over a wide range of wavelengths. Also determine the radial dependence of the scattered light measurements. Derive the possible impact on HST observations. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FOS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2144c PI: Christopher Burrows Proposal Title: NEAR AND MID ANGLE SCATTERING MEASUREMENT TEST ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi Christopher Burrows ST SCI USA X Peter Stockman ST SCI USA Olivia Lupie ST SCI USA Dan Schroeder BELOIT COLLEGE USA Bill Fastie JOHNS HOPKINS UNIVERSITY USA Ron Downes APPLIED RESEARCH CORPORATION USA Richard Griffiths ST SCI USA ------------------------------------------------------------------------------------ 2. Scientific Justification. Test Description: Determine the effect of internal HST light scattering. Use spectroscopic measurements taken within a radius of approximately 25 arc seconds from a bright (V about 7) target star. The scattering may be due to dust particles or minute surface irregularities in the OTA mirror surfaces. Determine the spectral energy distribution by obtaining low resolution spectra over a wide range of wavelengths. Also determine the radial dependence of the scattered light measurements. Derive the possible impact on HST observations. Page 3 ------------------------------------------------------------------------------------ 3. Description of proposed observations. The detectors of the FOS are used to sample the sky immediately surrounding a bright star. Scattering will be caused by dust particles within the OTA or microscopic irregularities of the OTA mirror surfaces. A series of HST attitudes will be chosen to point the FOS at selected offset positions from the star which lie along a line at 45 degrees to the spider diffraction peaks. Spectroscopic data is taken in both the red and blue FOS channels. The FOS spertures increase in size with distance from the star. Measurements with a new aperture will overlap a portion of those obtained from the previously used aperture to enable the diffraction at the aperture to be accounted for as a function of wavelength. The FOS will enable a precise determination of the spectral energy distribution of the scattered light and any radial dependence close to the target. FOS spectral intensity measurements will provide an estimate of the wavelength dependence of the scattered light and some indication of the type and size of the scattering source. The WFC photometric data will enable a determination of the radial dependence of the intensity of scattered light at the furthest positions measured from the target. Test Procedure: Three phase FOS/PEAK: FOS TA: (FOS/BL), ACQ/PEAK, 1.0-PAIR-A FOS TA: (FOS/BL), ACQ/PEAK, 0.25-PAIR-A FOS TA: (FOS/BL), ACQ/PEAK, 0.1-PAIR-A FOS/BL, ACCUM, Grating G160L, time 5S, S/N=30, 1.0 -PAIR-A and 0.1-PAIR-A Offset radius: 0.1 arcsec, 43S,S/N=10. Offset radius: 0.2 arcsec, 31S,S/N=3.0 Offset radius: 0.4 arcsec, 110S,S/N=2.0 Offset radius: 0.8 arcsec, 219S,S/N=1.0 Select 0.25-PAIR-A, offset 0.4 arcsec,29S,S/N=3.0 Offset radius: 0.8 arcsec, 101S,S/N=2.0 Offset radius: 1.6 arcsec, 203S,S/N=1.0 Offset radius: 3.2 arcsec, 900S Select 1.0-PAIR-A, offset 3.2 arcsec,300S Offset radius: 6.4 arcsec,500S SKY: Offset radius: 60 arcsec, 500S (FOS/RD), ACQ/PEAK, 1.0- PAIR-A,G650L (3770-8900), ACQ/PEAK, 0.25-PAIR-A ACQ/PEAK, 0.1-PAIR-A FOS/RD, ACCUM, Grating G650L 60S, 1.0-PAIR-A and 0.1-PAIR-A apertures Offset radius: 0.1 arcsec, 156S,S/N=10. Offset radius: 0.2 arcsec, 112S,S/N=3.0 Offset radius: 0.4 arcsec, 399S,S/N=2.0 Select 0.25-PAIR-A, offset 0.4 arcsec,64S,S/N=3.0 Offset radius: 0.8 arcsec, 227S,S/N=2.0 Offset radius: 1.6 arcsec, 454S,S/N=1.0 Select 1.0-PAIR-A, offset 1.6 arcsec,255S,S/N=3.0 Offset radius: 3.2 arcsec,277S,S/N=1.0 Offset radius: 6.4 arcsec,300S Select 2.0-BAR, offset 6.4 arcsec, 300S Offset radius: 12.8 arcsec, 300s Offset radius: 25.6 arcsec, 1200s Offset radius: 180 arcsec, 600s ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Submitted as an Observatory Level Test ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. Test Requirements: - Exp lines which call for large offsets (27,29,31,66), use gyro track - Optical image quality should be near Level 1 (lambda / 8). - No observations made during SAA passage. - FGS/SI Phase III alignments are complete for the FOS. (1527) - Onboard (Mode II) FOS peak-up target acquisition is functional. (2195) - The POS TARG offsets were calculated using a position angle in the radial direction which approximately bissected the V2V3 axes. This direction is required to avoid the scattered light from the secondary spider. Test Repetition: - No repetitions of this OLT are scheduled during SV. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. Real Time Data Analysis Requirements: Not anticipated at this time. Off Line Data Analysis Requirements: FOS Observations: o Compare the spectrum taken with the FOS positioned at the sky background position to the spectra obtained at each of the offset positions for each detector and aperture combination. o Derive the following: o Intensity ratios at selected wavelengths. o Intensity ratios at various radial distances. o Estimate of wavelength dependence of intensity ratios. o Estimate of radial dependence of intensity ratios. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. Page 4 ------------------------------------------------------------------------------------ 9. Description of previous HST work. Results of this OLT will be documented in an ST ScI Technical Report with distribution to appropriate personnel. Portions of this test will be presented at the HST symposium following the SV mission phase. Test results may also be submitted for pub- lication in an appropriate technical journal. ------------------------------------------------------------------------------------ 11. Address Information Name: CHRIS Y BURROWS Category: Institution: STSCI Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: 301-338-4780 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2144c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD44927 BRIGHT A2V STAR RA=06H 25M 32.9S +/- 0.1S, 2000 1 V = 7.10 +/- 0.05, TYPE = A2V DEC=+23D 19' 37" +/- 1" 2 B = 7.07 +/- 0.05 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2144c [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD44927 FOS/BL ACQ/ 1.0- G160L SEARCH-SIZE=6 1 1S 30 1 1 ONBOARD ACQ FOR 2 PEAK PAIR-A SCAN-STEP=0.5 GROUP 1-15 WITHIN 48H CYCLE 0 / 1-54 ------------------------------------------------------------------------------------------------------------------------------------ 2 HD44927 ^ ACQ/ 0.25- ^ SEARCH-SIZE=5 1 1S 30 ^ ONBOARD ACQ FOR 3 PEAK PAIR-A SCAN-STEP=0.2 ------------------------------------------------------------------------------------------------------------------------------------ 3 HD44927 ^ ACQ/ 0.1- ^ SEARCH-SIZE=5 1 1S 30 ^ ONBOARD ACQ FOR 4- PEAK PAIR-A SCAN-STEP=0.04 15 ------------------------------------------------------------------------------------------------------------------------------------ 4 HD44927 ^ ACCUM 1.0- G160L STEP-TIME=0.125 1 5S 10 ^ SEQ 4-8 NO GAP PAIR-A ------------------------------------------------------------------------------------------------------------------------------------ 4.5 HD44927 ^ ^ 0.1- ^ STEP-TIME=0.125 1 5S 10 ^ PAIR-A ------------------------------------------------------------------------------------------------------------------------------------ 5 HD44927 ^ ^ ^ ^ 1 43S 10 ^ POS TARG 0.08,- 0.06 ------------------------------------------------------------------------------------------------------------------------------------ 6 HD44927 ^ ^ ^ ^ 1 31S 3 ^ POS TARG 0.16,- 0.12 ------------------------------------------------------------------------------------------------------------------------------------ 7 HD44927 ^ ^ ^ ^ 1 110S 2 ^ POS TARG 0.32,- 0.24 ------------------------------------------------------------------------------------------------------------------------------------ 8 HD44927 ^ ^ ^ ^ 1 219S 1 ^ POS TARG 0.64,- 0.48 ------------------------------------------------------------------------------------------------------------------------------------ 9 HD44927 FOS/BL ACCUM 0.25- G160L 1 29S 3 ^ SEQ 9-12 NO GAP PAIR-A POS TARG 0.32,- 0.24 ------------------------------------------------------------------------------------------------------------------------------------ 10 HD44927 FOS/BL ACCUM 0.25- G160L 1 101S 2 1 1 POS TARG 0.64,- PAIR-A 0.48 ------------------------------------------------------------------------------------------------------------------------------------ 11 HD44927 ^ ^ ^ ^ 1 203S 1 ^ POS TARG 1.28,- 0.96 ------------------------------------------------------------------------------------------------------------------------------------ 12 HD44927 ^ ^ ^ ^ 1 900S 1 ^ POS TARG 2.56,- 1.92 ------------------------------------------------------------------------------------------------------------------------------------ 13 HD44927 FOS/BL ACCUM 1.0- G160L 1 300S 3 ^ SEQ 13-15 NO GAP PAIR-A POS TARG 2.56,- 1.92 ------------------------------------------------------------------------------------------------------------------------------------ 14 HD44927 ^ ^ ^ ^ 1 500S 1 ^ POS TARG 5.12,- 3.83 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2144c [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 15 HD44927 ^ ^ ^ ^ 1 500S 3 ^ POS TARG 48.0,- 35.9 GUID TOL 0.01" Comments: SKY 60" FROM TARGET. ------------------------------------------------------------------------------------------------------------------------------------ 38 HD44927 FOS/RD ACQ/ 1.0- G650L SEARCH-SIZE=6 1 0.3S 30 1 1 ONBOARD ACQ FOR PEAK PAIR-A SCAN-STEP=0.5 39 GROUP 38-54 WITHIN 48H ------------------------------------------------------------------------------------------------------------------------------------ 39 ^ ^ ACQ/ 0.25- ^ SEARCH-SIZE=5 1 0.3S 30 ^ ONBOARD ACQ FOR 40 PEAK PAIR-A SCAN-STEP=0.2 ------------------------------------------------------------------------------------------------------------------------------------ 40 ^ ^ ACQ/ 0.1- ^ ^ SEARCH-SIZE=5 1 0.3S 30 ^ ONBOARD ACQ FOR PEAK PAIR-A SCAN-STEP=0.04 41-54 ------------------------------------------------------------------------------------------------------------------------------------ 41 HD44927 FOS/RD ACCUM 1.0- G650L 3770- 1 60S 30 1 1 SEQ 41-44 NO GAP PAIR-A 8900 ------------------------------------------------------------------------------------------------------------------------------------ 41.5 HD44927 ^ ^ 0.1- ^ ^ 1 60S 10 ^ PAIR-A ------------------------------------------------------------------------------------------------------------------------------------ 42 HD44927 ^ ^ ^ ^ ^ 1 156S 10 ^ POS TARG 0.08,0.06 ------------------------------------------------------------------------------------------------------------------------------------ 43 HD44927 ^ ^ ^ ^ ^ 1 112S 3 ^ POS TARG 0.16,0.12 ------------------------------------------------------------------------------------------------------------------------------------ 44 HD44927 ^ ^ ^ ^ ^ 1 399S 2 ^ POS TARG 0.32,0.24 ------------------------------------------------------------------------------------------------------------------------------------ 45 HD44927 FOS/RD ACCUM 0.25- ^ ^ 1 64S 3 ^ SEQ 45-47 NO GAP PAIR-A POS TARG 0.32,0.24 ------------------------------------------------------------------------------------------------------------------------------------ 46 HD44927 ^ ^ ^ ^ ^ 1 227S 2 ^ POS TARG 0.64,0.48 ------------------------------------------------------------------------------------------------------------------------------------ 47 HD44927 ^ ^ ^ ^ ^ 1 454S 1 ^ POS TARG 1.28,0.96 ------------------------------------------------------------------------------------------------------------------------------------ 48 HD44927 FOS/RD ACCUM 1.0- ^ ^ 1 255S 3 ^ SEQ 48-51 NO GAP PAIR-A POS TARG 1.28,0.96 ------------------------------------------------------------------------------------------------------------------------------------ 49 HD44927 ^ ^ ^ ^ ^ 1 227S 1 ^ POS TARG 2.56,1.92 ------------------------------------------------------------------------------------------------------------------------------------ 50 HD44927 ^ ^ ^ ^ ^ 1 1817S 1 ^ POS TARG 5.12,3.83 ------------------------------------------------------------------------------------------------------------------------------------ 51 HD44927 FOS/RD ACCUM 2.0-BAR G650L 3770- 1 300S 1 1 1 POS TARG 5.12,3.83 8900 ------------------------------------------------------------------------------------------------------------------------------------ 52 HD44927 FOS/RD ACCUM 2.0-BAR G650L 3770- 1 300S 1 1 1 POS TARG 10.24, 8900 7.66 ------------------------------------------------------------------------------------------------------------------------------------ 53 HD44927 FOS/RD ACCUM 2.0-BAR G650L 3770- 1 1200S 1 1 1 POS TARG 20.48, 8900 15.36 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2144c [ 8] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 54 HD44927 FOS/RD ACCUM 2.0-BAR G650L 3770- 1 300S 1 1 1 POS TARG 144.0, 8900 107.7 Comments: OFFSET 180" FROM TARGET. USE GYRO TRACKING FOR LINE 54. ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2144c [ 9] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL ^ FOS/RD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK ACCUM ^ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SEARCH-SIZE=6 SCAN-STEP=0.5 SEARCH-SIZE=5 SCAN-STEP=0.2 SCAN-STEP=0.04 STEP-TIME=0.125 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for SV/OLT ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 2; GROUP 1-15 WITHIN 48H; CYCLE 0 / 1-54; ONBOARD ACQ FOR 3 ONBOARD ACQ FOR 4-15 SEQ 4-8 NO GAP POS TARG 0.08,-0.06 POS TARG 0.16,-0.12 POS TARG 0.32,-0.24 POS TARG 0.64,-0.48 SEQ 9-12 NO GAP; POS TARG 1.28,-0.96 POS TARG 2.56,-1.92 SEQ 13-15 NO GAP; POS TARG 5.12,-3.83 POS TARG 48.0,-35.9; GUID TOL 0.01"; ONBOARD ACQ FOR 39; GROUP 38-54 WITHIN 48H ONBOARD ACQ FOR 40 41-54; SEQ 41-44 NO GAP POS TARG 0.08,0.06 POS TARG 0.16,0.12 POS TARG 0.32,0.24 SEQ 45-47 NO GAP; POS TARG 0.64,0.48 POS TARG 1.28,0.96 SEQ 48-51 NO GAP; POS TARG 2.56,1.92 POS TARG 5.12,3.83 POS TARG 5.12,3.83; POS TARG 10.24,7.66; POS TARG 20.48,15.36; POS TARG 144.0,107.7; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G160L ^ G650L ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD44927 ------------------------------------------------------------------------------------------------------------------------------------