9369( 3) - 10/01/02 16:23 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9369 Version: 3 Check-in Date: 01-Oct-2002 16:22:47 1.Proposal Title: A Direct Test for Dust-driven Wind Physics ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Alex Lobel Smithsonian Institution Astrophysical Observatory CoI: Dr. Andrea Dupree Smithsonian Astrophysical Observatory N CoI: Dr. Robert Kurucz Smithsonian Astrophysical Observatory N CoI: Dr. Robert Stefanik Oak Ridge Observatory N ------------------------------------------------------------------------------------ 5. Abstract We propose to perform with STIS a critical test of the physical mechanism of wind acceleration by dust drag in cool stars. Spatially resolved spectra of the circumstellar environment of Alpha Ori (M2 Iab) will directly test if radiation pressure onto dust grains provides the momentum that causes the high mass-loss rates (up to 10^-6 M_odot yr^-1) observed in asymptotic giant branch and red supergiant stars. Terminal gas outflow velocities of 13-14 km, s^-1 are observed in Betelgeuse's circumstellar dust shell. However, the smaller chromospheric outflow velocities (below 6 km, s^- 1), point to an extended region in the circumstellar environment where the wind accelerates. Stellar wind theory suggests radiation pressure onto dust grains as the driving mechanism that drags the gas outflow to these high terminal velocities. Dynamic radiative transport calculations that fit the star's 9.7 Mum silicate dust emission indicate that this wind accelerating region is located between 0.78" and ~3". We propose to use STIS to obtain a high- resolution spatial and spectral raster scan across this region. These data can only be obtained for this unique nearby supergiant with the exceptional capabilities of the STIS. An increase of the observed asymmetry of the self-absorbed Mg ii h line (which forms in an expanding gas shell) with distance from the star, will directly confirm (or reject) the theory of dust-driven wind acceleration in cool stars. ------------------------------------------------------------------------------------ 9369( 3) - 10/01/02 16:23 - [ 2] Observations Description ------------------------ Obtain echelle spectra of Betelgeuse with the medium resolution (E230M) grating in the wavelength range of 2275 Angstrom to 3120 Angstrom. The spectra require guide star acquisition, target acquisition with a low resolution photometric observation with first order grating G230LB (wavelength range 1685 to 3065 Angstrom, resolution ~700; estimated exposure time 10 s for S/N~100), and a peak up in a small slit. Visit 01: Orbit 1: Perform a raster scan in off-sets of +200 mas with the 0.2*0.06 slit over 5 subsequent orbits. For the centered POS TARG 0.0, 0.0 exposure use the 0.1*0.03 slit during 250 S. During same orbit 1, use the 0.2*0.06 slit for the POS TARG 0.2, 0.0 exposure of 500 S. Orbit 2: obtain exposures at POS TARG 0.4, 0.0 during 1000 S., and at POS TARG 0.6, 0.0 during 2000 S. For an expected flux in the Mg ii h-line of 5 10^-15 cgs, off-limb at 780 mas-1", use the large slit (6*0.2, E230M) to obtain S/N~10 during an exposure time of ~10, 000 s, which can be integrated over three subsequent orbits. Orbit 3, 4, 5: obtain with the 0.2*0.06 slit three subsequent exposures of 3000 S at POS TARG 1.0, 0.0. Repeat for the two outer off-limb scan positions at POS TARG 2.0, 0.0 and 3.0, 0.0 during visits 02 and 03. In order to detect faint optical material in the circumstellar dust shell surrounding this bright source, perform two short imaging visits with the STIS coronographic imaging facility, preceding the POS TARG 2.0, 0.0 and 3.0, 0.0 exposures. The 50CORON mask aperture (50*50) provides a bandpass of ~2000-10300 Angstrom, suitable to detect faint brightness patterns at the predicted inner dust condensation radius of 780 mas-1". Visit 02: Orbit 1: After CCD target acquisition with F25ND5 filter, obtain coronographic image with the BAR 10" wedge for an exposure time of 1 S (no CR-SPLIT). Use WEDGEA1.0 for three subsequent images; expose during 0.1 S, 1 S, and 10 S, respectively. Apply CR- SPLIT=NO for 0.1 S exposure only. In the same orbit obtain low resolution photometric observation with first order grating G230LB. Switch to STIS/NUV- MAMA, and obtain echelle spectrum with 0.1*0.03 during 250 S at POS TARG 0.0, 0.0. Orbit 2, 3, 4: obtain with the 0.2*0.06 slit three subsequent exposures of 3000 S at POS TARG 2.0, 0.0. Visit 03: Change the roll orientation to +15 degrees from the nominal of visit 02. Repeat visit 02 for images, and spectroscopy at POS TARG 3.0, 0.0. Cycle 11: STIS: visit 01: Spectroscopic raster scan in off-sets of +200 mas during 5 orbits visit 02: Coronographic imaging, and spectra at TP 2.0, 0.0 visit 03: Imaging with Orient 15 D from 02; spectra at TP 3.0, 0.0 Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9369( 3) - 10/01/02 16:23 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD39801 STAR, M III-I RA=05H 55M 10.29S +/- 0.02", 2000 V = +19 V = 0.8+/-0.5 DEC=07D 24' 25.3" +/- 0.02" TYPE=M2IAB B-V = 1.86+/-0.04 U-B = 2.06+/-0.05 E(B-V) = 0.21 Coordinate Source: HIPPARCOS/TYCHO_CATALOGUE Comments: Proper motion from GSC Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 0.001667 0.0090 0.0076 9369( 3) - 10/01/02 16:23 - [ 4] Visit: 01 Visit Priority: Visit Requirements: BETWEEN 01-Sep-2002 AND 01-Dec-2002 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 HD39801 STIS/C ACQ F25ND5 MIRROR 1 0.1 S CD Comments: Source centered after AQC ------------------------------------------------------------------------------------------------------------------------------------ 20 HD39801 STIS/C ACCUM 52X0.5 G230LB 2375 1 20 S CD Comments: Expect S/N 110 in 40s. Brightest pixel at 4180 e-. ------------------------------------------------------------------------------------------------------------------------------------ 30 HD39801 STIS/C ACQ/PEA 0.2X0.2 G230LB 2375 1 1 S CD K Comments: Expect about 450, 000 cts over spectrum per s. ------------------------------------------------------------------------------------------------------------------------------------ 35 HD39801 STIS/C ACQ/PEA 0.1X0.0 G230LB 2375 1 1 S CD K 3 ------------------------------------------------------------------------------------------------------------------------------------ 40 HD39801 STIS/N ACCUM 0.1X0.0 E230M 2707 1 250 S POS TARG 0.000, 0.000 UV-MAM 3 A Comments: Peak rate 3/s, global 153, 000 /s in em. max Mg II at 10^-11 cgs ------------------------------------------------------------------------------------------------------------------------------------ 50 HD39801 STIS/N ACCUM 0.2X0.0 E230M 2707 1 500 S POS TARG 0.200, 0.000 UV-MAM 6 A Comments: Peak rate 0.47/s, global 26, 000 /s in continuum at 10^-12 cgs ------------------------------------------------------------------------------------------------------------------------------------ 60 HD39801 STIS/N ACCUM 0.2X0.0 E230M 2707 1 1000 S POS TARG 0.400, 0.000 UV-MAM 6 A Comments: Peak rate 0.24/s, global 13, 600 /s in continuum at 5 10^-13 cgs ------------------------------------------------------------------------------------------------------------------------------------ 70 HD39801 STIS/N ACCUM 0.2X0.0 E230M 2707 1 2000 S POS TARG 0.600, 0.000 UV-MAM 6 A Comments: Peak rate 0.12/s, global 7, 500 /s in continuum at 2.5 10^-13 cgs ------------------------------------------------------------------------------------------------------------------------------------ 80 HD39801 STIS/C ACQ F25ND5 MIRROR 1 0.1 S CD Comments: Source centered after AQC ------------------------------------------------------------------------------------------------------------------------------------ 9369( 3) - 10/01/02 16:23 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 90 HD39801 STIS/C ACQ/PEA 0.2X0.2 G230LB 2375 1 1 S CD K ------------------------------------------------------------------------------------------------------------------------------------ 95 HD39801 STIS/C ACQ/PEA 0.2X0.0 G230LB 2375 1 1 S CD K 6 Comments: ONBOARD re-acquisition for 100-110 ------------------------------------------------------------------------------------------------------------------------------------ 100 HD39801 STIS/N ACCUM 0.2X0.0 E230M 2707 1 1400 S POS TARG 1.000, 0.000 UV-MAM 6 A Comments: Peak rate 0.005/s, global 1, 590/s in Mg II at 5 10^-15 cgs ------------------------------------------------------------------------------------------------------------------------------------ 110 HD39801 STIS/N ACCUM 0.2X0.0 E230M 2707 2 3000 S POS TARG 1.000, 0.000 UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 9369( 3) - 10/01/02 16:23 - [ 6] Visit: 02 Visit Priority: Visit Requirements: BETWEEN 01-Feb-2003 AND 01-May-2003 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 HD39801 STIS/C ACQ F25ND5 MIRROR 1 0.1 S CD Comments: Source centered after AQC ------------------------------------------------------------------------------------------------------------------------------------ 20 HD39801 STIS/C ACQ/PEA 0.3X0.0 MIRROR 1 1.0 S CD K 5ND Comments: ONBOARD ACQ for 30-70 ------------------------------------------------------------------------------------------------------------------------------------ 30 HD39801 STIS/C ACCUM BAR10 MIRROR GAIN=4 1 1 S CD Comments: Picture of 1 s with BAR 10 ------------------------------------------------------------------------------------------------------------------------------------ 40 HD39801 STIS/C ACCUM BAR10 MIRROR GAIN=4 1 10 S CD Comments: Picture of 10 s with BAR 10 ------------------------------------------------------------------------------------------------------------------------------------ 50 HD39801 STIS/C ACCUM WEDGEA1 MIRROR GAIN=4,CR-SPLIT=NO 1 0.1 S CD .0 Comments: Picture of 0.1 s with WEDGEA 1.0 ------------------------------------------------------------------------------------------------------------------------------------ 60 HD39801 STIS/C ACCUM WEDGEA1 MIRROR GAIN=4 1 1 S CD .0 Comments: Picture of 1 s with WEDGEA 1.0 ------------------------------------------------------------------------------------------------------------------------------------ 70 HD39801 STIS/C ACCUM WEDGEA1 MIRROR GAIN=4 1 10 S CD .0 Comments: Picture of 10 s with WEDGEA 1.0 ------------------------------------------------------------------------------------------------------------------------------------ 80 HD39801 STIS/C ACQ/PEA 0.1X0.0 G230LB 2375 1 1 S CD K 3 Comments: ONBOARD re-acquisition for 90-100 ------------------------------------------------------------------------------------------------------------------------------------ 90 HD39801 STIS/N ACCUM 0.1X0.0 E230M 2707 1 250 S POS TARG 0.000, 0.000 UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 100 HD39801 STIS/N ACCUM 0.2X0.0 E230M 2707 3 3000 S POS TARG 2.000, 0.000 UV-MAM 6 A Comments: Peak rate 0.005/s, global 1, 590/s in Mg II at 5 10^-15 cgs ------------------------------------------------------------------------------------------------------------------------------------ 9369( 3) - 10/01/02 16:23 - [ 7] Visit: 03 Visit Priority: Visit Requirements: ORIENT 15D TO 15D FROM 02 BETWEEN 01-Feb-2003 AND 01-May-2003 AFTER 02 BY 45 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 HD39801 STIS/C ACQ F25ND5 MIRROR 1 0.1 S CD Comments: Source centered after AQC ------------------------------------------------------------------------------------------------------------------------------------ 20 HD39801 STIS/C ACQ/PEA 0.3X0.0 MIRROR 1 1.0 S CD K 5ND Comments: ONBOARD ACQ for 30-70 ------------------------------------------------------------------------------------------------------------------------------------ 30 HD39801 STIS/C ACCUM BAR10 MIRROR GAIN=4 1 1 S CD Comments: Picture of 1 s with BAR 10 ------------------------------------------------------------------------------------------------------------------------------------ 40 HD39801 STIS/C ACCUM BAR10 MIRROR GAIN=4 1 10 S CD Comments: Picture of 10 s with BAR 10 ------------------------------------------------------------------------------------------------------------------------------------ 50 HD39801 STIS/C ACCUM WEDGEA1 MIRROR GAIN=4,CR-SPLIT=NO 1 0.1 S CD .0 Comments: Picture of 0.1 s with WEDGEA 1.0 ------------------------------------------------------------------------------------------------------------------------------------ 60 HD39801 STIS/C ACCUM WEDGEA1 MIRROR GAIN=4 1 1 S CD .0 Comments: Picture of 1 s with WEDGEA 1.0 ------------------------------------------------------------------------------------------------------------------------------------ 70 HD39801 STIS/C ACCUM WEDGEA1 MIRROR GAIN=4 1 10 S CD .0 Comments: Picture of 10 s with WEDGEA 1.0 ------------------------------------------------------------------------------------------------------------------------------------ 80 HD39801 STIS/C ACQ/PEA 0.1X0.0 G230LB 2375 1 1 S CD K 3 Comments: ONBOARD re-acquisition for 90-100 ------------------------------------------------------------------------------------------------------------------------------------ 90 HD39801 STIS/N ACCUM 0.1X0.0 E230M 2707 1 250 S POS TARG 0.000, 0.000 UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 100 HD39801 STIS/N ACCUM 0.2X0.0 E230M 2707 3 3000 S POS TARG 3.000, 0.000 UV-MAM 6 A Comments: Peak rate 0.005/s, global 1, 590/s in Mg II at 5 10^-15 cgs ------------------------------------------------------------------------------------------------------------------------------------ 9369( 3) - 10/01/02 16:23 - [ 8] Summary Form for Proposal 9369 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F25ND5 52X0.5 0.2X0.2 0.1X0.03 0.2X0.06 0.3X0.05ND BAR10 WEDGEA1.0 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM ACQ/PEAK ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters GAIN=4 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 01-Sep-2002 AND 01-Dec-2002 POS TARG 0.000, 0.000 POS TARG 0.200, 0.000 POS TARG 0.400, 0.000 POS TARG 0.600, 0.000 POS TARG 1.000, 0.000 BETWEEN 01-Feb-2003 AND 01-May-2003 POS TARG 2.000, 0.000 ORIENT 15D TO 15D FROM 02 BETWEEN 01-Feb-2003 AND 01-May-2003 AFTER 02 BY 45 D POS TARG 3.000, 0.000 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G230LB E230M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD39801 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 2375 2707 ------------------------------------------------------------------------------------------------------------------------------------