! 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 <free-text>
! 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
! <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