! Proposal 5825, submission 1 ! PI: Dr. Amanda S. Bosh ! Received Wed Mar 1 17:01:04 EST 1995 ! From: amanda@lowell.edu ! file: %M% ! SCCSid: %Z%%M% %I% %G% ! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal Template ! $Id: 5825,v 13.1 1995/07/24 21:32:49 pepsa Exp $ ! ! Refer to the HST Phase II Proposal Instructions to fill this out ! ! Anything after a "!" is ignored, and may be deleted ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: Andy Lubenow ! Phone: 410 338-4928 , E-mail: lubenow@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: bosh-715.prop ! Date generated: Fri Dec 16 14:31:13 EST 1994 ! Proposal_Information ! Section 4 Title: The Structure of Triton's Lower Atmosphere Proposal_Category: GO Scientific_Category: Solar System Cycle: 5 Investigators PI_name: Dr. Amanda S. Bosh PI_Institution: Lowell Observatory CoI_Name: Prof. James L. Elliot CoI_Institution: Massachusetts Institute of Technology Contact: N ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) With the occultation of Tr148 (McDonald and Elliot, submitted) in August 1995, we have the opportunity to distinguish between two competing models for Triton's lower atmosphere (Tyler et al. 1989; Strobel and Summers 1994). Additionally, we will be acquiring data on an atmosphere that has been predicted to be changing quite rapidly (Hansen and Paige 1992; Spencer and Moore 1992). High quality occultation data sets are crucial for testing these theories and establishing the changing state of Triton's atmosphere. Questions ! Free format text (please update) Observing_Description: (1) Within 48 hours before or after the occultation observation, obtain spectrum of star with G650L/RD and PRISM (to be used during the occultation observation). This determines the spectrum of the star for later use in data analysis. (2) At least one orbit before the start of the occultation observations, acquire an ``offset- acquisition" star: one that is within 1.5 arcmin of the star to be occulted but further from Triton and Neptune than the target star. This offset acquisition technique has been successfully implemented before (GTO/HSP1081) to avoid problems with target acquisition in the bright scattered light background near Triton and Neptune. A suitable offset acquisition candidate will be chosen after ground-based astrometric frames are obtained and analyzed. (3) Blind offset to Tr148. Prior astrometry will have determined the relative positions of these two stars to better than 0.1 arcsec, assuring accurate placement of the target star in the science aperture. Obtain confirmatory ACQ exposure to verify placement of Tr148 in science aperture. (4) Track on Tr148 while Triton's atmosphere passes in front of it (1 orbit). The one atmosphere observation will last about 15 minutes. We will be using only 374 diodes in the PRISM to increase our temporal resolution. (5) Within 48 hours before or after the occultation observation, obtain spectra of Triton. This observation establishes the spectra of Triton separately, without any stellar component. This will be used in later analyses. Cycle 5: Primary Orbits: 4 Exposures: 13 Real_Time_Justification: Time-critical: stellar occultations by solar system bodies are inherently time-critical observations. They occur at a particular time, determined by the planetary ephemeris and star position; therefore, no other dates/times are acceptable. We will provide ground-based astrometry prior to the event. With this astrometry we will locate an offset acquisition target and determine its position relative to Tr148 with an accuracy of better than 0.1 arcsec. We will also use this astrometry to refine the predicted impact time. If astrometry indicates that the HST will not be in the occultation shadow, we will not observe this event, but will choose another event instead. We also plan to apply for observing time at ground-based stations to acquire the necessary multiple chords across Triton. The S/N and resolution from such a site will be inferior to that from HST, but will be sufficient to constrain the impact parameter. Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: TR148 Alternate_Names: Description: STAR Position: RA=19H 41M 00.376S +/- 0.01S, DEC=-20D 51' 41.20" +/- 0.1", ! PLATE-ID=0000 Equinox: J2000 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: V=12.9 +/- 0.1, ! Include at least V and B-V B-V=0.7 +/- 0.1, V-R=0.4 +/- 0.1, V-I=0.8 +/- 0.1 Comments: Star position will be updated >=2 months before observation is performed. If occultation shadow zone will not be in HST observability, we will not observe this target. Contact: Amanda S. Bosh, Lowell Observatory. Solar_System_Targets ! Section 5.2 Target_Number: 3 Target_Name: TRITON Description: SATELLITE TRITON Level_1: STD = NEPTUNE ! Satellite of Sun Level_2: STD = TRITON ! Satellite of Level_1 Level_3: ! Satellite of Level_2 Window: Flux: V = 13.52 +/- 0.05, ! Include at least V and B-V B-V=0.72 +/- 0.05 Comments: Triton along the apparent path of the occulted star. Scan starting position parameters will be updated after final astrometry and revised occultation prediction. Generic_Targets ! Section 5.3 Scan_Data ! Appendix B Scan_Number: 1 FGS_Scan: Cont_or_Dwell: C Dwell_Points: Dwell_Secs: Scan_Width: 0.0 Scan_Length: 5.0 Sides_Angle: 90.0 Number_Lines: 1 Scan_Rate: 0.075 First_Line_PA: 79.4 Scan_Frame: CEL Length_Offset: 2.5 Width_Offset: 0.0 Visits ! Section 6 Visit_Number: 1 Visit_Requirements: PCS MODE Fine GROUP 1-4 WITHIN 48H BETWEEN 14-AUG-95:04:00 AND 14-AUG-95:05:40 On_Hold_Comments: Visit_Comments: OCC-ACQ. Fine lock if possible; if not, coarse track is acceptable. The BETWEEN time is computed to be the beginning of the target acq sequence. The actual event is observed in exp 40, and occurs at 7:48+/-2m, and is of aprox 200 sec durration. The data-taking exposure time should cover the time between 7:40 and 7:55. Exposure_Number: 10 ! Section 6.5 Target_Name: TR148 Config: FOS/RD Opmode: ACQ/BINARY Aperture: 4.3 Sp_Element: MIRROR Wavelength: Optional_Parameters: bright=168000 faint=420 Number_of_Iterations: 1 Time_Per_Exposure: 1.0S Special_Requirements: ONBOARD ACQ FOR 20 ! Section 7.2 Comments: Time_per_exposure will change after offset acquisition star is chosen. Exposure_Number: 20 ! Section 6.5 Target_Name: TR148 Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.3 Sp_Element: PRISM Wavelength: Optional_Parameters: SCAN-STEP-X = 0.11, SCAN-STEP-Y = 0.11, SEARCH-SIZE-X = 5, SEARCH-SIZE-Y = 5 Number_of_Iterations: 1 Time_Per_Exposure: 1.0S Special_Requirements: ONBOARD ACQ FOR 30-40 ! Section 7.2 Comments: Time_per_exposure will change after offset acquisition star is chosen. Using Binary & Peak acquisitions to achieve 0.08" pointing accuracy (sequence Z+D2 from CAL/FOS-132). Exposure_Number: 30 ! Section 6.5 Target_Name: TR148 Config: FOS/RD Opmode: ACQ Aperture: 4.3 Sp_Element: MIRROR Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 4S Special_Requirements: end orbit ! Section 7.2 Comments: FOS ACQIMAGE OF FIELD OF VIEW Exposure_Number: 40 ! Section 6.5 Target_Name: TR148 Config: FOS/RD Opmode: RAPID Aperture: 1.0 Sp_Element: PRISM Wavelength: Optional_Parameters: READ-TIME = 0.231, SUB-STEP = 1, COMB = NO, STEP-TIME = 0.2 ! = LT, no DT or ROT. This is for ! 1 step pos. in the patter, bec. ! SUB-STEP = 1 and COMB = NO. This ! applies to all occultation exposures. Number_of_Iterations: 1 Time_Per_Exposure: 15m Special_Requirements: EXPAND ! Section 7.2 MIN DUR MAX DUR END ORBIT Comments: IGNORE SAA. Can split exposure across SAA. Event occurs at 14-AUG-95:07:48 +/- 2M and has duration aprox 200 seconds. USE DIODES 139-512 ONLY I.S. (Dahlem) recomends: USE DIODES 124-497 (partial scattered light correction). Visit_Number: 3 Visit_Requirements: PCS MODE Fine On_Hold_Comments: Visit_Comments: STAR-SPECTRA. Fine lock if possible; if not, coarse track is acceptable. Exposure_Number: 50 ! Section 6.5 Target_Name: TR148 Config: FOS/RD Opmode: ACQ/BINARY Aperture: 4.3 Sp_Element: MIRROR Wavelength: Optional_Parameters:bright=168000 faint=420 Number_of_Iterations: 1 Time_Per_Exposure: 1.0S Special_Requirements: ONBOARD ACQ FOR 60 ! Section 7.2 Comments: Time_per_exposure may change after photometry of star is obtained. Do not execute within +/- 72M of Visit 2. Exposure_Number: 60 ! Section 6.5 Target_Name: TR148 Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.3 Sp_Element: PRISM Wavelength: Optional_Parameters: SCAN-STEP-X = 0.17, SCAN-STEP-Y = 0.17, SEARCH-SIZE-X = 4, SEARCH-SIZE-Y = 4 Number_of_Iterations: 1 Time_Per_Exposure: 1.0S Special_Requirements: ONBOARD ACQ FOR 70-90 ! Section 7.2 Comments: Time_per_exposure may change after photometry of star is obtained. Using Binary & Peak acquisitions to achieve 0.12" pointing accuracy (sequence Z+E1 from CAL/FOS-132). Exposure_Number: 70 ! Section 6.5 Target_Name: TR148 Config: FOS/RD Opmode: RAPID Aperture: 1.0 Sp_Element: PRISM Wavelength: Optional_Parameters: READ-TIME = 0.231, SUB-STEP = 1, COMB = NO, STEP-TIME = 0.2 Number_of_Iterations: 1 Time_Per_Exposure: 23.1S Special_Requirements: ! Section 7.2 Comments: USE DIODES 139-512 ONLY I.S. (Dahlem) recomends: USE DIODES 124-497 (partial scattered light correction). Get spectrum of occulted star when it is away from Triton/Neptune. Same parameters as occultation. Exposure_Number: 80 ! Section 6.5 Target_Name: TR148 Config: FOS/RD Opmode: ACCUM Aperture: 1.0 Sp_Element: PRISM Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 60S Special_Requirements: ! Section 7.2 Comments: Get spectrum of occulted star when it is away from Triton/Neptune. Parameters set to optimize signal, calibration ability. Exposure_Number: 90 ! Section 6.5 Target_Name: TR148 Config: FOS/RD Opmode: ACCUM Aperture: 1.0 Sp_Element: G650L Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 60S Special_Requirements: ! Section 7.2 Comments: Get spectrum of occulted star when it is away from Triton/Neptune. Parameters set to optimize signal, calibration ability. Visit_Number: 4 Visit_Requirements: PCS MODE Fine On_Hold_Comments: Visit_Comments: BACK-SCANS. Fine lock if possible; if not, coarse track is acceptable. Exposure_Number: 100 ! Section 6.5 Target_Name: TRITON Config: FOS/RD Opmode: ACQ/BINARY Aperture: 4.3 Sp_Element: MIRROR Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 0.93S Special_Requirements: ONBOARD ACQ FOR 110 ! Section 7.2 Comments: Do not execute within +/- 72M of Visit 2. Exposure_Number: 110 ! Section 6.5 Target_Name: TRITON Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.3 Sp_Element: PRISM Wavelength: Optional_Parameters: SCAN-STEP-X = 0.17, SCAN-STEP-Y = 0.17, SEARCH-SIZE-X = 4, SEARCH-SIZE-Y = 4 Number_of_Iterations: 1 Time_Per_Exposure: 0.94S Special_Requirements: ONBOARD ACQ FOR 120-130 ! Section 7.2 Comments: Using Binary & Peak acquisitions to achieve 0.12" pointing accuracy (sequence Z+E1 from CAL/FOS-132). Exposure_Number: 120 ! Section 6.5 Target_Name: TRITON Config: FOS/RD Opmode: RAPID Aperture: 1.0 Sp_Element: PRISM Wavelength: Optional_Parameters: READ-TIME = 0.231, SUB-STEP = 1, COMB = NO, STEP-TIME = 0.2 Number_of_Iterations: 1 Time_Per_Exposure: 66.99S Special_Requirements: SPATIAL SCAN 1 SINGLE-EXP ! Section 7.2 Comments: USE DIOES 139-512 ONLY I.S. (Dahlem) recomends: USE DIODES 124-497 (partial scattered light correction). Scan parameters and Time_Per_Exposure will change with final geometric track prediction. Exposure_Number: 130 ! Section 6.5 Target_Name: TRITON Config: FOS/RD Opmode: ACCUM Aperture: 1.0 Sp_Element: PRISM Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 60S Special_Requirements: ! Section 7.2 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 ! PI Address from Phase I is: ! ! 1400 W. Mars Hill Road, ! Flagstaff, AZ 86001 ! ! Ship_Via: UPS ! UPS (2-day) or OVERNIGHT ! Overnight shipping done at PI expense Recipient_Email: ! Needed if Ship_To: is not PI_Address !