7423( 6) - 03/10/98 09:58 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7423 Version: 6 Check-in Date: 10-Mar-1998 09:56:33 1.Proposal Title: CRL2688: The Rosetta Stone for the Evolution of AGB Red Giants into Bipolar Planetary Nebulae ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: RAGHVENDRA SAHAI Jet Propulsion Laboratory CoI: John Trauger Jet Propulsion Lab/ Caltech N CoI: Joel Kastner Massachusetts Institute of Technology N CoI: David Weintraub Vanderbilt University N ------------------------------------------------------------------------------------ 5. Abstract A 260 sec wide-band (606 nm) WFPC2 image of the bipolar protoplanetary nebula CRL2688 has led to our discovery of a large number of bright arcs around, and a pair of radial "searchlight- beams" emerging from, within the vicinity of the obscured central star. The arcs are the first direct evidence for irregular variations in the mass-loss rate throughout the 10^4 yr history of mass-ejection from the progenitor AGB star. The razor-sharp edges of the searchlight beams have overturned a long-held paradigm for the density structure of CRL2688. CRL2688 has thus become the Rosetta Stone for the evolution of AGB red giants to bipolar planetary nebulae, We therefore propose to use WFPC2 and NICMOS to conduct a optical and infrared imaging study of CRL2688. Deep imaging at 450, 606 & 814 nm, and polarimetric imaging at 1 and 2micron (together with our previous 606 nm polarimetric imaging) will allow us to probe the mass-ejection process at look-back times >~ 10^4 yr, accurately characterise the structure of the arcs, the mass of the nebula and progenitor star, and tightly constrain the properties of the dust grains, as well as the precise location of the central star. Imaging of the 2.1micron H_2 line emission will probe the interaction of the high-velocity outflow and the dense AGB wind, which is believed to mediate the red giant-to-planetary nebula transformation. Our detailed study promises to lead to major breakthroughs in our understanding of late stellar evolution. ------------------------------------------------------------------------------------ 7423( 6) - 03/10/98 09:58 - [ 2] Observations Description ------------------------ A) The NICMOS exposures will produce (1) deep imaging of a 38"x38" area centred on CRL2688 in the F160W filter (2) deep F212N & F215N exposures, together with sky background measurements, to image the S(1) molecular H2 emission, in a 19"x19" FOV centred on CRL2688 (3) 2 micron Polarimetric measurements of a 19"x19" region centred on CRL2688 using POL0L, POL120L, POL240L, and sky background measurements B) The WFPC exposures will produce deep images in the F606W and F380W filters. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- We would like to modify, perhaps extensively, our NICMOS exposures based on the NICMOS/ERO results on CRL2688 (proposal 7115). ------------------------------------------------------------------------------------ Data Distribution Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7423( 6) - 03/10/98 09:58 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CRL2688 STAR, POST-AGB STAR, RA= 21H 02M 18.7S +/- 0.01S, J2000 B = 15.5 EJECTA, ISM, PLANETARY DEC=36D 41' 38.0" +/- 0.1" V = 14.0 NEBULA, REFLECTION U = 8.9 NEBULA K = 8.2 7423( 6) - 03/10/98 09:58 - [ 4] Visit: 01 Visit Priority: Visit Requirements: SCHED 100% ORIENT 283D TO 295D On Hold Comments: Additional Comments: ORIENT is chosen so as to let the long axis of CRL2688, at PA=19 lie along the diagonal of NIC2. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 30 CRL2688 NIC2 MULTIAC NIC2-FI F212N PATTERN=SPIRAL-DITH,NUM-POS=3, 1 DEF POS TARG 0.5000, -0.6917 CUM X DITH-SIZE=1.558,SAMP-SEQ=STEP16, PAR 31-32 WITH 30 NSAMP=24 ------------------------------------------------------------------------------------------------------------------------------------ 31 ANY NIC1 ACCUM NIC1 F166N 1 288 S ------------------------------------------------------------------------------------------------------------------------------------ 32 ANY NIC3 ACCUM NIC3 F212N 1 288 S ------------------------------------------------------------------------------------------------------------------------------------ 40 CRL2688 NIC2 MULTIAC NIC2-FI F215N PATTERN=SPIRAL-DITH,NUM-POS=3, 1 DEF POS TARG 0.5000, -0.6917 CUM X DITH-SIZE=1.558,SAMP-SEQ=STEP16, PAR 41-42 WITH 40 NSAMP=24 ------------------------------------------------------------------------------------------------------------------------------------ 41 ANY NIC1 ACCUM NIC1 F166N 1 288 S ------------------------------------------------------------------------------------------------------------------------------------ 42 ANY NIC3 ACCUM NIC3 F212N 1 288 S ------------------------------------------------------------------------------------------------------------------------------------ 50 CRL2688 NIC2 MULTIAC NIC2-FI F212N PATTERN=SPIRAL-DITH,NUM-POS=3, 1 DEF POS TARG 0.5000, -0.6917 CUM X DITH-SIZE=1.558,SAMP-SEQ=STEP16, PAR 51-52 WITH 50 NSAMP=22 ------------------------------------------------------------------------------------------------------------------------------------ 51 ANY NIC1 ACCUM NIC1 F166N 1 256 S ------------------------------------------------------------------------------------------------------------------------------------ 52 ANY NIC3 ACCUM NIC3 F212N 1 256 S ------------------------------------------------------------------------------------------------------------------------------------ 60 CRL2688 NIC2 MULTIAC NIC2-FI F215N PATTERN=SPIRAL-DITH,NUM-POS=3, 1 DEF POS TARG 0.5000, -0.6917 CUM X DITH-SIZE=1.558,SAMP-SEQ=STEP16, PAR 61-62 WITH 60 NSAMP=22 ------------------------------------------------------------------------------------------------------------------------------------ 61 ANY NIC1 ACCUM NIC1 F160W 1 256 S ------------------------------------------------------------------------------------------------------------------------------------ 62 ANY NIC3 ACCUM NIC3 F212N 1 256 S ------------------------------------------------------------------------------------------------------------------------------------ 70 CRL2688 NIC2 MULTIAC NIC2-FI F215N PATTERN=SPIRAL-DITH,NUM-POS=3, 1 DEF POS TARG 0.5000, -0.6917 CUM X DITH-SIZE=1.558,SAMP-SEQ=STEP16, PAR 71-72 WITH 70 NSAMP=22 ------------------------------------------------------------------------------------------------------------------------------------ 71 ANY NIC1 ACCUM NIC1 F160W 1 256 S ------------------------------------------------------------------------------------------------------------------------------------ 72 ANY NIC3 ACCUM NIC3 F212N 1 256 S ------------------------------------------------------------------------------------------------------------------------------------ 340 CRL2688 NIC1 MULTIAC NIC1-FI POL0S PATTERN=SPIRAL-DITH,NUM-POS=4, 1 DEF POS TARG 0.5000, -0.6917 CUM X DITH-SIZE=1.3185,SAMP-SEQ=STEP16, NSAMP=19 ------------------------------------------------------------------------------------------------------------------------------------ 7423( 6) - 03/10/98 09:58 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 344 CRL2688 NIC1 MULTIAC NIC1-FI POL120S PATTERN=SPIRAL-DITH,NUM-POS=4, 1 DEF POS TARG 0.5000, -0.6917 CUM X DITH-SIZE=1.3185,SAMP-SEQ=STEP16, NSAMP=19 ------------------------------------------------------------------------------------------------------------------------------------ 347 CRL2688 NIC1 MULTIAC NIC1-FI POL240S PATTERN=SPIRAL-DITH,NUM-POS=4, 1 DEF POS TARG 0.5000, -0.6917 CUM X DITH-SIZE=1.3185,SAMP-SEQ=STEP16, NSAMP=19 ------------------------------------------------------------------------------------------------------------------------------------ 350 CRL2688 WFPC2 IMAGE WF3-FIX F606W CLOCKS=YES,CR-TOLERANCE=0.0, 1 60 S CR-SPLIT=NO,ATD-GAIN=7 ------------------------------------------------------------------------------------------------------------------------------------ 355 CRL2688 WFPC2 IMAGE WF3-FIX F606W CLOCKS=YES,CR-TOLERANCE=0.0, 4 200 S CR-SPLIT=NO,ATD-GAIN=7 ------------------------------------------------------------------------------------------------------------------------------------ 360 CRL2688 WFPC2 IMAGE WF3-FIX F380W CLOCKS=YES,CR-TOLERANCE=0.0, 1 200 S CR-SPLIT=NO,ATD-GAIN=7 ------------------------------------------------------------------------------------------------------------------------------------ 365 CRL2688 WFPC2 IMAGE WF3-FIX F380W CLOCKS=YES,CR-TOLERANCE=0.0, 2 300 S CR-SPLIT=NO,ATD-GAIN=7 ------------------------------------------------------------------------------------------------------------------------------------ 7423( 6) - 03/10/98 09:58 - [ 6] Summary Form for Proposal 7423 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations NIC2 NIC1 NIC3 WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters PATTERN=SPIRAL-DITH NUM-POS=3 DITH-SIZE=1.558 SAMP-SEQ=STEP16 NSAMP=24 NSAMP=22 NSAMP=19 DITH-SIZE=1.3185 NUM-POS=4 ATD-GAIN=7 CR-SPLIT=NO CR-TOLERANCE=0.0 CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SCHED 100% ORIENT 283D TO 295D POS TARG 0.5000, -0.6917 PAR 31-32 WITH 30 POS TARG 0.5000, -0.6917 PAR 41-42 WITH 40 POS TARG 0.5000, -0.6917 PAR 51-52 WITH 50 POS TARG 0.5000, -0.6917 PAR 61-62 WITH 60 POS TARG 0.5000, -0.6917 PAR 71-72 WITH 70 POS TARG 0.5000, -0.6917 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F212N F166N F215N F160W POL0S POL120S POL240S F606W F380W ------------------------------------------------------------------------------------------------------------------------------------ Target Names CRL2688 ANY ------------------------------------------------------------------------------------------------------------------------------------