8674( 3) - 02/08/01 12:06 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8674 Version: 3 Check-in Date: 08-Feb-2001 12:05:31 1.Proposal Title: STIS coronographic imaging of old PMS stars ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 9 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Anne-Marie Lagrange Groupe d'Astrophysique de Grenoble CoI: Dr David Mouillet Laboratoire d'Astrophysique de Grenoble Y CoI: Jean Charles Augereau Laboratoire d'Astrophysique de Grenoble N CoI: Dr Fran\c cois Menard Canada France Hawaii Telescope N ------------------------------------------------------------------------------------ 5. Abstract In the past decade, circumstellar (CS) disks of short-lived dust and gas have been evidenced around Main Sequence (MS) stars (e.g. beta Pictoris). The dust and gas are probably due to planetesimal collisions and/or comet evaporation. These so called ``second generation disks'' are then believed to trace the history of planetary systems formation, in a stage where planetesimals are numerous and planets may be already formed, i.e. an evolved stage compared to the disks around young stars such as Classical T Tauri stars, but yet prior to mostly dust-free planetary systems such as those revealed by radial velocity searches. We recently began to investigate the missing link between MS and young stars CS environments by searching for second generation disks of dust or gas around the few known old PMS stars and by modeling their CS environments. Our HST/NICMOS images revealed a disk around HD141569 (10 Myrs), and possibly also (but still to be confirmed) around HD100546 and HD135344. We propose here to use the unprecedent detection capabilities of STIS/CORON to get high signal-to-noise (SN) images of HD141569 and HD135344. This will allow to study in much more detail the HD141569 disk, to confirm or infirm the other disk, and to perform fine modeling of the CS dust. This is a key step in the study of the complete evolution of (proto)planetary systems, from the PMS to the MS stages. ------------------------------------------------------------------------------------ 8674( 3) - 02/08/01 12:06 - [ 2] Observations Description ------------------------ We will use the coronographic capability (1'' wedge) in order to avoid the saturation on the bright point sources (V = 7 -- 9), and to take advantage of the Lyot stop rejection. Thanks to this wedge, the flux on the brightest pixel is reduced by a factor > 10^4. Our NICMOS data indicate disk magnitudes ranging between 17 and 19 arcsec^-2 between 4 and 6''. According to the ETC, 10 minutes observations will then provide a 150 -- 60 SNR respectively: in the read-out noise limitted regime, these STIS observations allow a much deeper investigation. The result will in addition be degraded by photon noise due to the occulted star PSF wings, and also, closer to the star, by PSF variation effects. These limits induce the following calibrations. For each object, the subtraction of residual PSF wings is necessary and requires specific exposures on comparison stars. These stars should be observed close in time (during the next orbit) to the science targets observations because of the slight possible variation of the PSF with time. This subtraction is the limitting factor for high contrast imaging in the vicinity of the star. These PSF calibrator are chosen with the same spectral type because of the combination of the very broad spectral band used in teh cornographic observations and some internal image chromaticity.- for HD135344: the target will be observed at 2 wedge positions (1" and 0.85" wide). And the field of view orientation is chosen so as to avoid the northward companion (21" away) to be within the detector an saturate. The PSF calibrator is observe at the same wedge positions.- for HD141569: 2 companions (10 times fainter) are located at ~ 7-8 arcsec from HD141569 A. In order to make long exposures (and not saturate the detector or induce a huge number of short exposures), we will select the orientation so that both HD141569 and the companions are occulted by the wedge (which requires an accuracy of < +/- 5 degres). HD141569 will be observed at 2 wedge positions (1.8" and 1" wide). The comparison star will be observed, at the positions of HD141569 A and at the positions of the companions, for the respective PSF wings subtraction. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8674( 3) - 02/08/01 12:06 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 10 HD135344 STAR RA=15H 15M 48.37S +/- 0.03S, J2000 V = 8.68+/-0.10 DEC=-37D 9' 17.1" +/- 0.4" Coordinate Source: HIPPARCOS_INPUT_CATALOGUE Comments: F4V 11 HD134970- STAR RA=15H 13M 50.33S +/- 0.04S, J2000 V = 8.56+/-0.20 CALIB DEC=-33D 31' 4.2" +/- 0.6" Coordinate Source: HIPPARCOS_INPUT_CATALOGUE Comments: F5V 20 HD141569 STAR RA=15H 49M 57.75S +/- 0.014S, J2000 V = 7.0+/-0.10 DEC=-03D 55' 16.5" +/- 0.2" Coordinate Source: HIPPARCOS_INPUT_CATALOGUE Comments: B9.5V 21 HD129433- STAR RA=14H 43M 13.57S +/- 0.007S, J2000 V = 5.73+/-0.1 CALIB DEC=-24D 59' 51.9" +/- 0.1" Coordinate Source: HIPPARCOS_INPUT_CATALOGUE Comments: B9.5V 8674( 3) - 02/08/01 12:06 - [ 4] Visit: 10 Visit Priority: Visit Requirements: GROUP 10-20 WITHIN 2 Orbits ORIENT 305D TO 360D On Hold Comments: Additional Comments: ORIENT such as the companion at 21" northward is not in the field Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 HD135344 STIS/C ACQ F28X50O MIRROR ACQTYPE=POINT 1 1.0 S CD II ------------------------------------------------------------------------------------------------------------------------------------ 12 HD135344 STIS/C ACCUM WEDGEA1 MIRROR CR-SPLIT=6,GAIN=4 1 1200.0 CD .0 Comments: = 6 exposures of 200 s ------------------------------------------------------------------------------------------------------------------------------------ 13 HD135344 STIS/C ACCUM WEDGEA1 MIRROR CR-SPLIT=7,GAIN=4 1 700.0 S POS TARG 0.0,-3.0 CD .0 Comments: = 7 exposures of 100 s, target under a 0.85" wedge ------------------------------------------------------------------------------------------------------------------------------------ 8674( 3) - 02/08/01 12:06 - [ 5] Visit: 20 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: PSF calibrator for visit 10. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 21 HD134970-CA STIS/C ACQ F28X50O MIRROR ACQTYPE=POINT 1 1.0 S LIB CD II ------------------------------------------------------------------------------------------------------------------------------------ 22 HD134970-CA STIS/C ACCUM WEDGEA1 MIRROR CR-SPLIT=7,GAIN=4 1 1260.0 LIB CD .0 Comments: = 7 exposures of 180 s (=200/1.12) ------------------------------------------------------------------------------------------------------------------------------------ 23 HD134970-CA STIS/C ACCUM WEDGEA1 MIRROR CR-SPLIT=7,GAIN=4 1 630.0 S POS TARG 0.0,-3.0 LIB CD .0 Comments: = 7 exposures of 90 s ------------------------------------------------------------------------------------------------------------------------------------ 8674( 3) - 02/08/01 12:06 - [ 6] Visit: 30 Visit Priority: Visit Requirements: ORIENT 80D TO 90D GROUP 30-40 WITHIN 2 Orbits On Hold Comments: Additional Comments: orientation so as to place the companions also under the wedge B Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 31 HD141569 STIS/C ACQ F28X50O MIRROR ACQTYPE=POINT 1 0.5 S CD II ------------------------------------------------------------------------------------------------------------------------------------ 32 HD141569 STIS/C ACCUM WEDGEB1 MIRROR CR-SPLIT=5,GAIN=4 1 1500.0 CD .8 Comments: = 5 exposures of 300s ------------------------------------------------------------------------------------------------------------------------------------ 33 HD141569 STIS/C ACCUM WEDGEB1 MIRROR CR-SPLIT=8,GAIN=4 1 400.0 S CD .0 Comments: = 8 exposures of 50s ------------------------------------------------------------------------------------------------------------------------------------ 8674( 3) - 02/08/01 12:06 - [ 7] Visit: 40 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: PSF calibrator for 30. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 41 HD129433-CA STIS/C ACQ F28X50O MIRROR ACQTYPE=POINT 1 0.2 S LIB CD II ------------------------------------------------------------------------------------------------------------------------------------ 42 HD129433-CA STIS/C ACCUM WEDGEB1 MIRROR CR-SPLIT=8,GAIN=4 1 744.0 S LIB CD .8 Comments: = 8 exposures of 93s (=300s / 3.22) ------------------------------------------------------------------------------------------------------------------------------------ 43 HD129433-CA STIS/C ACCUM WEDGEB1 MIRROR CR-SPLIT=3,GAIN=4 1 279.0 S POS TARG 8.0, 0.0 LIB CD .8 Comments: = 3 exposures of 93s, at the position of the companions ------------------------------------------------------------------------------------------------------------------------------------ 44 HD129433-CA STIS/C ACCUM WEDGEB1 MIRROR CR-SPLIT=8,GAIN=4 1 124.0 S LIB CD .0 Comments: = 8 exposures of 15.5s (=50s / 3.22) ------------------------------------------------------------------------------------------------------------------------------------ 45 HD129433-CA STIS/C ACCUM WEDGEB1 MIRROR CR-SPLIT=3,GAIN=4 1 46.5 S POS TARG 8.0, 0.0 LIB CD .0 Comments: = 3 exposures of 15.5s, at the position of the companions ------------------------------------------------------------------------------------------------------------------------------------ 8674( 3) - 02/08/01 12:06 - [ 8] Summary Form for Proposal 8674 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50OII WEDGEA1.0 WEDGEB1.8 WEDGEB1.0 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT GAIN=4 CR-SPLIT=7 CR-SPLIT=5 CR-SPLIT=8 CR-SPLIT=3 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GROUP 10-20 WITHIN 2 Orbits ORIENT 305D TO 360D POS TARG 0.0,-3.0 ORIENT 80D TO 90D GROUP 30-40 WITHIN 2 Orbits POS TARG 8.0, 0.0 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD135344 HD134970-CALIB HD141569 HD129433-CALIB ------------------------------------------------------------------------------------------------------------------------------------