Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2830c Report Date: 09-May-96:17:25 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 CAL/OTA Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Hashima Hasan ST SCI USA (301) 338-4519 ------------------------------------------------------------------------------------ 7. Abstract Test Objectives - THIS IS A CONTINGENCY PROPOSAL. It will be used to determine the effect of internal HST light scattering if unsatisfactory results are obtained from SV. Use spectroscopic measurements taken within a radius of approximately 40 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: 2 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FOS WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2830c PI: Hashima Hasan Proposal Title: NEAR AND MID ANGLE SCATTERING MEASUREMENT TEST ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 2. Scientific Justification. Test Description - THIS IS A CONTINGENCY TEST. Determine the effect of internal HST light scattering. Use spectroscopic measurements taken within a radius of approximately 40 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. ------------------------------------------------------------------------------------ 3. Description of proposed observations. The scattering measurement test is made up of two overlapping parts. First 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. When the star is a safe distance from the apertures and the signal to noise ratio of the stray light component is appreciably attenuated, a second much brighter star is used as the source of stray light. Measurements are overlapped to give a spectro-photometric calibration of the new and brighter star. The WF/PC in its WFC mode is used to obtain exposures at the largest distances from the aperture. In these cases, the WFC is used as a wide field photometer. 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: Spectra are taken for different offsets and apertures using FOS BLUE with G160L grating and FOS RED with G650L grating. Depending on the offset position two different target stars of varying brightness are used for each FOS mode. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Submitted as an Observatory Level Test Page 3 ------------------------------------------------------------------------------------ 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. - Relative positions of bright star (?) and guide stars known to 0.3 arcsec (1 sigma) accuracy. - 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. -NOTE: There will be an extremely bright target (V = 0.6) present in the focal plane during a portion of this OLT. It will be offset from 6 arsec to a degree from the FOS 2.0 arc second aperture ------------------------------------------------------------------------------------ 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. WFC Observations: o Choose suitably spaced bins in radius across the FOV. For each bin, find the histogram and remove the tail caused by sources. Extract the background and radial dependence. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. ------------------------------------------------------------------------------------ 9. Description of previous HST work. Results of this OLT will be documented in an ST ScI Technical Report with distribution to appropriate personnel. Test results may also be submitted for publication in an appropriate technical journal. ------------------------------------------------------------------------------------ 11. Address Information Name: HASHIMA HASAN Category: PI Institution: ST SCI Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ Name: HASAN N HASHIMA Category: Institution: STSCI Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: 301-338-4519 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 2830c [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 2 HD122451 VERY BRIGHT B1III STAR RA=14H 03M 49.4S +/- 0.1S, 2000 1 V = 0.61 +/- 0.01, TYPE = B1 BETA CEN DEC=-60D 22' 22" +/- 1" 2 B = 0.38 +/- 0.01 ------------------------------------------------------------------------------------------------------------------------------------ 3 TBD-STAR- OFFSET STAR NEAR RA = 14H 03M 00.00S +/- 2000 1 V=14 OFFSET HD122451 1.0S, DEC = -60D 22' 00" +/- 1" Comments: THIS IS A STAR NEAR BETA CEN TO ACQUIRE FIRST TO MAKE SURE BETA CEN IS KEPT WELL AWAY FROM APERTURE. BRIAN MCCLEAN WILL SUPPLY STAR AROUND JUNE 1. (BCW) ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2830c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 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 1-31 WITHIN 48H ------------------------------------------------------------------------------------------------------------------------------------ 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 0.1- G160L 1 5S 30 ^ SEQ 4-8 NO GAP 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 1623S 1 ^ POS TARG 2.56,- 1.92 ------------------------------------------------------------------------------------------------------------------------------------ 13 HD44927 FOS/BL ACCUM 1.0- G160L 1 913S 3 ^ SEQ 13-15 NO GAP PAIR-A POS TARG 2.56,- 1.92 ------------------------------------------------------------------------------------------------------------------------------------ 14 HD44927 ^ ^ ^ ^ 1 311S 1 ^ POS TARG 5.12,- 3.83 ------------------------------------------------------------------------------------------------------------------------------------ 14.5 HD44927 ^ ^ ^ ^ 1 800S 1 ^ POS TARG 10.24,- 7.66 ------------------------------------------------------------------------------------------------------------------------------------ 15 HD44927 ^ ^ ^ ^ 1 913S 3 ^ POS TARG 48.0,- 35.9 GUID TOL 0.01" Comments: SKY 60" FROM TARGET. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2830c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 21.5 TBD-STAR- FOS/BL ACQ/ 4.3 MIRROR BRIGHT=66000 1 0.5S 1 1 ONBOARD ACQ FOR 22 OFFSET BINARY -27 Comments: BLIND OFFSET. ACQUIRE THIS STAR TO CHECK LOCATION (I.E. NOT NEAR BETA CEN), THEN BLIND OFFSET TO 22. ------------------------------------------------------------------------------------------------------------------------------------ 22 HD122451 ^ ^ ^ ^ 1 16S 10 ^ POS TARG 10.25,- 6.52 Comments: SCHEDULERS - MAKE SURE POS TARG IS WORKING FOR ALL OBSERVATIONS SINCE THE STAR IS 0TH MAGNITUDE AND WOULD DAMAGE THE INSTRUMENT. ------------------------------------------------------------------------------------------------------------------------------------ 23 HD122451 ^ ^ ^ ^ 1 62S 10 ^ POS TARG 20.5,- 14.19 ------------------------------------------------------------------------------------------------------------------------------------ 24 HD122451 FOS/BL ACQ/ 4.3 MIRROR 1 250S 10 1 1 POS TARG 40.99,- BINARY 29.53 ------------------------------------------------------------------------------------------------------------------------------------ 25 HD122451 ^ ^ ^ ^ 1 90S 3 ^ POS TARG 81.98,- 60.2 ------------------------------------------------------------------------------------------------------------------------------------ 26 HD122451 ^ ^ ^ ^ 1 40S 1 ^ POS TARG 164.0,- 121.6 ------------------------------------------------------------------------------------------------------------------------------------ 27 HD122451 ^ ^ ^ ^ 1 160S 1 ^ POS TARG 327.9,- 244.3 GUID TOL 0.01" Comments: GYRO TRACKING ACCEPTABLE ------------------------------------------------------------------------------------------------------------------------------------ 29 HD122451 FOS/BL ACCUM 2.0-BAR G160L 1 639S 1 ^ POS TARG 655.9,- 489.7 GUID TOL 0.01" Comments: GYRO TRACKING ACCEPTABLE ------------------------------------------------------------------------------------------------------------------------------------ 31 HD122451 FOS/BL ACCUM 2.0-BAR G160L 1 639S 1 ^ POS TARG 2882,- 2156 GUID TOL 0.01" Comments: GYRO TRACKING ACCEPTABLE; SKY: 60' FROM TARGET ------------------------------------------------------------------------------------------------------------------------------------ 32 HD122451 WFC IMAGE ALL F336W SUM=2X2 1 600S 1 ^ POS TARG 84.85, 84.85 ------------------------------------------------------------------------------------------------------------------------------------ 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 38-51 WITHIN 48H ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2830c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 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 41-51 ------------------------------------------------------------------------------------------------------------------------------------ 41 HD44927 FOS/RD ACCUM 0.1- G650L 1 86S 30 1 1 SEQ 41-44 NO GAP 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 1.0- G650L 1 1817S 1 1 1 POS TARG 48.0,35.9 PAIR-A Comments: SKY: 60" FROM TARGET ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2830c [ 8] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL ^ WFC FOS/RD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK ACCUM ^ ACQ/BINARY IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SEARCH-SIZE=6 SCAN-STEP=0.5 SEARCH-SIZE=5 SCAN-STEP=0.2 SCAN-STEP=0.04 BRIGHT=66000 SUM=2X2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for CAL/OTA ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 2; GROUP 1-31 WITHIN 48H; 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 10.24,-7.66 POS TARG 48.0,-35.9; GUID TOL 0.01"; ONBOARD ACQ FOR 22-27; POS TARG 10.25,-6.52 POS TARG 20.5,-14.19 POS TARG 40.99,-29.53 POS TARG 81.98,-60.2 POS TARG 164.0,-121.6 POS TARG 327.9,-244.3; GUID TOL 0.01" POS TARG 655.9,-489.7; POS TARG 2882,-2156; POS TARG 84.85, 84.85 ONBOARD ACQ FOR 39; GROUP 38-51 WITHIN 48H ONBOARD ACQ FOR 40 41-51; 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 48.0,35.9 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G160L ^ MIRROR F336W G650L ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD44927 HD122451 BETA CEN TBD-STAR-OFFSET ------------------------------------------------------------------------------------------------------------------------------------