! Hubble Space Telescope Cycle 5 (1995) Phase II Proposal Template ! $Id: 6049,v 8.1 1996/11/18 18:41:22 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: Denise Taylor ! Phone: 410 338-4824 , E-mail: dctaylor@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Date generated: Sun Dec 18 11:38:35 EST 1994 ! Proposal_Information ! Section 4 Title: Monitoring the size and shape of Mira-- type stars throughout their pulsation cycles Proposal_Category: GO Scientific_Category: Cool Stars Cycle: 5 Investigators PI_name: Mario G. Lattanzi PI_Institution: Space Telescope Science Institite CoI_Name: M.W. Feast CoI_Institution: University of Cape Town Contact: ! Y or N (designate at most one contact) CoI_Name: U. Munari CoI_Institution: Osservatorio Astronomico di Padova Contact: ! Y or N (designate at most one contact) CoI_Name: P.A. Whitelock CoI_Institution: South African Astronomical Observatory Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) We propose to utilize the unmatched angular resolution in the visual of the astrometer FGS, in an attempt to measure SIZES and SHAPES of Miras variables and their variations with the pulsation phase. In particular, it would be possible, for the first time, to cover the full 4\div6 (average) magnitude range of a pulsation cycle with the same instrument and with a fairly high signal--to--noise throughout. The scientific return is potentially very rewarding. Mapping the variations of Mira diameters is of key importance for the detailed understanding of their pulsation mechanism, and ultimately, for the use of Miras as galactic and extragalactic distance indicators. Also, confirmation of elliptical projected disks would set constraints on the existence and relevance of non- radial pulsations. The programme is particularly suited for the FGS, the only orbiting interferometer. It requires, together, all of those outstanding characteristics, high angular resolution, large dynamical range, and faint (for an interferometer) magnitude limit, which make this wide--band visual interferometer unique compared to ground based facilities. Questions ! Free format text (please update) Observing_Description: To achieve the scientific goals set forth earlier, the science exposures proposed all use the TRANS mode of the astrometer FGS (FGS 3). As described in the FGS Instrument Handbook (Version 4.0), and in recently published papers (Bernacca, Lattanzi et al. 1993, Lattanzi et al. 1994) this mode samples the interference fringe produced by the Koester's prism interferometer, the "heart" of the Fine Guidance Sensor. There are two Koester's prism interferometers in each FGS. These are fed by a beam-- splitter to give sensitivity in two orthogonal directions, usually referred to as X and Y axes. When a TRANS mode observation is executed, the FGS istantaneous field-of-view scans across the target at a fixed 45^degrees angle to the X and Y axes. Therefore, each FGS3 TRANS scan produces two fringes which can then be independently analyzed for signatures other than those characteristic of the FGS3 standard single star UP69. Indeed, deviations from the single star fringes is what is used to measure projected angular diameters (Figs. 1 and 2). Possible asymmetry of the measured X and Y projected diameters are easily oriented on the sky utilizing HST attitude data and the measurements themselves. Although the circumstances for the detectability of any deviation from spherical symmetry are several, the chance is statistically reasonable. Assuming an axially symmetric shape (oblate spheroid), we stand fairly good chances to observe some ellipticity of such shape when projected on the sky (worst case being zero inclination of the axis of symmetry to the observer). The probability is further reduced by the necessity that the semi--major axis of the ellipse be aligned as closely as possible to the FGS axes for maximum effect on the projected fringes. Neverthless, visual interpolation among the simulated fringes in Figs. 1 and 2 shows that it should not be difficult to measure accurately differences of 20\ in the projected diameters as derived from the X-- and Y- - fringes. Figs. 1 and 2 show also that the FGS should be able to measure variations of 6\div10 mas in angular diameters larger than 20\div25 mas. To maximize the accuracy of these measurements, it is necessary to achieve maximum S/N and proper sampling of the interferometric fringe. We than propose to execute 30 TRANS scans per visit (per target). The required on--sky length/scan is 2."1 (1".5 per FGS axis). Each scan is sampled every 0".008, i.e., pixels of 0".006 per FGS axis. Following the Cycle 5 Phase I Proposal Instructions volume, each visit comprises a guide star acquisition (12 min), the set--up time (including the selected filter) for TRANS mode (3 min), then the science exposure. Given that each science exposure consists of 30 TRANS scans of the kind defined above, and that each sample along the scan takes a fixed 0.025 sec, the 30 scans take 31.3 min, for a total of 12+3+31.3 = 46.3 min per visit. This is less than the visibility period per orbit. Therefore, we request one orbit per visit per target. Recent observations (Lattanzi et al. 1994 and references therein) show that scans with the same pixel size and same filter element (PUPIL) give optimal resolution with minimum scan time. Multiple, consecutive scans are required for three reasons. First, spacecraft jitter can corrupt fringes. With multiple scans one can identify jitter--corrupted fringes and reject them. Second, multiple scans are the only reliable way to check on the repeatibility of a detection. Finally, multiple scans are co- -added to increase the signal--to--noise ratio (S/N). This is crucial for best resolution during the reductions and to allow for star variability (our targets have quite large magnitude variations). Successful exposures should yield co-- added fringes with typical S/N > 60. We request 7 visits per target. All of the visits on R Car and R Leo are in Cycle 5. Two visits of R Cas and one visit of R Hya are left for Cycle 6 in order to complete the coverage of their pulsation cycles. Seven visits per target allow to derive an angular diameter value at any time along the pulsation cycle with an error comparable to that of the measured values (~ sqrt3/7 mas for a perfect cosine model). This is assuming the diameter variations are modelled as a simple cosine function of time with three parameters and a 1--mas error for each of the seven measured diameters. All of our targets will be too bright during part of their pulsation cycles to be observed with the PUPIL element and the 5--mag neutral density filter will then be required. It is necessary to have F5ND fringes of the FGS single star standard UP69. Routine TRANS mode calibration observations on UP69 run by the STScI provide reference data for the PUPIL element but not for the F5ND filter. We have therefore added two F5ND calibration orbits on UP69 in Cycle 5 and we foresee 1 for Cycle 6. Length, pixel size, and number of scans in the calibration visits are the same as for the science observations. The two Cycle 5 calibrations visits will be placed as close in time as possible to the F5ND science observations. Should the STScI Cycle 5 calibration plan for TRANS mode include the F5ND filter , the calibrations orbits requested would not be necessary. Real_Time_Justification: None. We plan to perform coordinated ground-based observations of the proposed targets with the telescopes in Sutherland (RSA) and Asiago (Italy) to which we have regular access as resident astronomers: beginitemize em UBVRI and JHKL photometry to derive bolometric light curves and colours; em high resolution spectroscopy to map the motion of the star atmosphere during the pulsation cycle and to study the profile evolution of emission lines at the head of the Balmer series. enditemize As said earlier, the programme stars are in the HIPPARCOS programme and satisfactory trigonometric parallaxes will therefore become available the beginning of 1996. Angular diameters could then be easily transformed into linear dimensions and, when combined with the photometric and spectroscopic ground-based observations, improve current understanding of the pulsation mechanism in Miras stars. Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: HD84748 Alternate_Names: R-LEO Description: STAR, Pulsating Variable Position: RA = 09H 47M 33.465S +/- 0.01S, DEC = +11D 25' 43.44" +/- 0.1" ! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: -0.0006 ! Units are seconds of time per year Dec_PM: -0.047 ! Units are seconds of arc per year Epoch: 2000 Annual_Parallax: 0.012 Flux: V=8.6 +/- 0.5 ! Include at least V and B-V Comments: variable color, brightest magnitude V=5.5, faintest V=10.2, Sp=M6 III Target_Number: 2 Target_Name: HD120285 Alternate_Names: W-Hya Description: STAR, Pulsating Variable Position: RA = 13H 49M 02.09S +/- 0.023S , DEC = -28D 22' 03.2" +/- 0.3" ! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox: 2000 RV_or_Z: RA_PM: -0.0029 ! Units are seconds of time per year Dec_PM: -0.060 ! Units are seconds of arc per year Epoch: 2000 Annual_Parallax: Flux: V=8.8 +/- 0.5 ! Include at least V and B-V Comments: variable color, brightest magnitude V=5.8, faintest V=9.7, Sp=M7 Visits ! Section 6 Visit_Number: 1 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 05-NOV-95 AND 14-NOV-95 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD84748 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: PUPIL Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 2 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 29-DEC-95 AND 11-JAN-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD84748 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: F5ND Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 3 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 28-JAN-96 AND 10-FEB-96 On_Hold_Comments: Visit_Comments: Pulsating Variable at its MAX brightness Exposure_Number: 1 ! Section 6.5 Target_Name: HD84748 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: F5ND Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 4 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 26-FEB-96 AND 11-MAR-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD84748 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: F5ND Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 5 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 27-APR-96 AND 10-MAY-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD84748 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: PUPIL Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 6 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 01-JUN-96 AND 14-JUN-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD84748 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: PUPIL Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 7 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 20-JUN-96 AND 28-JUN-96 On_Hold_Comments: Visit_Comments: Pulsating Variable at its MIN brightness Exposure_Number: 1 ! Section 6.5 Target_Name: HD84748 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: PUPIL Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 8 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 7-OCT-96 AND 14-OCT-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD84748 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: PUPIL Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 9 Visit_Requirements: ! Section 7.1 PCS MODE F BEFORE 13-FEB-1997 Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD120285 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: PUPIL Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=15 Number_of_Iterations: 1 Time_Per_Exposure: 937.0S Special_Requirements: SEQ 1-2 NON-INT ! Section 7.2 Comments: Exposure_Number: 2 ! Section 6.5 Target_Name: HD120285 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: F5ND Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=15 Number_of_Iterations: 1 Time_Per_Exposure: 937.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 10 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 16-DEC-95 AND 25-DEC-95 On_Hold_Comments: Visit_Comments: Pulsating Variable at its MIN brightness Exposure_Number: 1 ! Section 6.5 Target_Name: HD120285 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: PUPIL Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 11 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 13-JAN-96 AND 26-JAN-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD120285 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: PUPIL Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 12 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 08-MAR-96 AND 21-MAR-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD120285 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: F5ND Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 13 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 02-MAY-96 AND 15-MAY-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD120285 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: F5ND Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 14 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 06-JUN-96 AND 19-JUN-96 On_Hold_Comments: Visit_Comments: Pulsating Variable is at its MAX brightness Exposure_Number: 1 ! Section 6.5 Target_Name: HD120285 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: F5ND Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 15 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 16-JUL-96 AND 29-JUL-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD120285 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: F5ND Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 16 Visit_Requirements: ! Section 7.1 PCS MODE F BETWEEN 09-SEP-96 AND 22-SEP-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD120285 Config: FGS Opmode: TRANS Aperture: 3 Sp_Element: F5ND Wavelength: Optional_Parameters: STEP-SIZE=0.6, SCANS=30 Number_of_Iterations: 1 Time_Per_Exposure: 1875.0S 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: ! ! 3700 San Martin Dr., ! Baltimore MD 21218 ! ! Ship_Via: UPS ! UPS (2-day) or OVERNIGHT ! Overnight shipping done at PI expense !Recipient_Email: ! Needed if Ship_To: is not PI_Address ! ! Let us know what you think of this template and software! ! Please send a list of your likes and dislikes to your Program Coordinator