6787( 4) - 05/02/96 09:58 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6787 Version: 4 Check-in Date: 02-May-1996 09:17:02 1.Proposal Title: Fine Structure in Ejection Nebulae Around Population I and II Wolf-Rayet Stars ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle HOT STARS GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Anthony Moffat Universite de Montreal CoI: Yves Grosdidier Universite de Montreal N CoI: Agnes Acker Observatoire de Strasbourg N CoI: Gilles Joncas Universite Laval N ------------------------------------------------------------------------------------ 6. Abstract We propose to use the unique high spatial resolution and wide field of WFPC2 to test quantitatively for the presence of supersonic, compressible turbulence in nebulae ejected by hot stars. Following the TAC's recommendation, this run is considered exploratory. We therefore limit it to imaging of a nebula around a high-mass Wolf- Rayet star: the youngest such nebula known, M1-67 = PK 050+03D1, around the WN8 star 209BAC = WR124. The wavelet technique will be used on a deep, net H--Alpha image, to derive spatial scaling laws [line-flux (which can be converted to mass) versus size; mass spectrum]. If supersonic, compressible turbulence prevails, as observed in other gaseous regions (e.g. molecular clouds or population I WR winds), we can expect to see specific power-laws, with rapidly increasing numbers of smaller features. Detection of strong turbulence will have an important impact on mass-loss estimates and stellar evolution. ------------------------------------------------------------------------------------ 6787( 4) - 05/02/96 09:58 - [ 2] Observations Description ------------------------ Based on our previous ground-based experience with M1-67, combined with the existing WFPC2 observations of the nebula around the recurrent nova T Pyx, we estimate that some 3 hours of accumulated narrowband H--Alpha imagery will be necessary to provide sufficient S/N to be able to trace clumps down to 0.1''. A more precise estimate of the exposure time is impossible before actually getting the data. Three hours correspond to some 6 orbits, including time to obtain reference continuum images in V and R, test images for scattered light, and a few short images in each filter that avoid saturation in the bright central star. By interpolation and appropriate scaling, the V and R images will be combined to a single image at the same wavelength as H--Alpha. This image will then, after further appropriate scaling, be subtracted from the mean of several deep individual H--Alpha images (to reduce the effects of saturation of the central star), to produce a final net image in H--Alpha of the nebula. In order to avoid problems with potential variable stars in the subtraction of starlight from the original H--Alpha images, it is preferable to obtain all the images of a given object within as contiguous a span of time as possible. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6787( 4) - 05/02/96 09:58 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 PK050+03D1 STAR,Wind,Wolf Rayet RA=19H 11M 30.90S +/- 0.02S, J2000 V=+195 SURF(R) = 21+/-0.5 (WN), ISM,Ring DEC=+16D 51' 38.4" +/- 0.3", SURF(B) = 24+/-0.5 Nebula,Emission Line PLATE-ID=02UP E(B-V) = 1.3+/-0.1 Nebula,Ejecta SURF-LINE(6562)=3+/-2e-15 SIZE=80+/-5 Comments: The position refers to that of the central star (WN8,V=11.1, B-V=1.1, E(B-V)=1.3). The surrounding nebula is nearly circular, with optical radius 40". 2 GSC01599- STAR,CALIBRATION, RA=19H 12M 18.07S +/- 0.02S, J2000 V = 10.9 00138 SCATTERED LIGHT TEST DEC=+16D 50' 55.50" +/- 0.3", B-V = 0.9 PLATE-ID=02UP Comments: This is a star well outside the nebula with nearly the same brightness as WR124 (GSC01599-00138 is 11' east of WR124). 3 HD179588 STAR,CALIBRATION, RA=19H 12M 34.40S +/- 0.02S, J2000 V = 6.73 SCATTERED LIGHT TEST DEC=+16D 50' 47.20" +/- 0.3" B-V = -0.01 Comments: This a very bright star 15' east of WR124, which will serve to calibrate the scattered light in H-Alpha in a reasonable time. 6787( 4) - 05/02/96 09:58 - [ 4] Visit: 01 Visit Requirements: PCS MODE F 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 PK050+03D1 WFPC2 IMAGE WFALL-F F555W ATD-GAIN=15 1 0.23S IX ------------------------------------------------------------------------------------------------------------------------------------ 2 PK050+03D1 WFPC2 IMAGE WFALL-F F675W ATD-GAIN=15 1 0.23S IX ------------------------------------------------------------------------------------------------------------------------------------ 3 PK050+03D1 WFPC2 IMAGE WFALL-F F656N ATD-GAIN=15 3 2S IX ------------------------------------------------------------------------------------------------------------------------------------ 4 PK050+03D1 WFPC2 IMAGE WFALL-F F656N ATD-GAIN=7 3 70S IX ------------------------------------------------------------------------------------------------------------------------------------ 5 PK050+03D1 WFPC2 IMAGE WFALL-F F675W ATD-GAIN=7 4 50S IX ------------------------------------------------------------------------------------------------------------------------------------ 6 PK050+03D1 WFPC2 IMAGE WFALL-F F555W ATD-GAIN=7 1 40S IX ------------------------------------------------------------------------------------------------------------------------------------ 7 PK050+03D1 WFPC2 IMAGE WFALL-F F656N ATD-GAIN=7,CR-SPLIT=NO 4 2500S IX ------------------------------------------------------------------------------------------------------------------------------------ 8 HD179588 WFPC2 IMAGE WFALL-F F656N ATD-GAIN=7 1 24S IX ------------------------------------------------------------------------------------------------------------------------------------ 9 HD179588 WFPC2 IMAGE WFALL-F F656N ATD-GAIN=7 1 500S IX ------------------------------------------------------------------------------------------------------------------------------------ 10 GSC01599-00 WFPC2 IMAGE WFALL-F F656N ATD-GAIN=15 1 7S 138 IX ------------------------------------------------------------------------------------------------------------------------------------ 11 GSC01599-00 WFPC2 IMAGE WFALL-F F555W ATD-GAIN=15 1 0.23S 138 IX ------------------------------------------------------------------------------------------------------------------------------------ 12 GSC01599-00 WFPC2 IMAGE WFALL-F F675W ATD-GAIN=15 1 0.23S 138 IX ------------------------------------------------------------------------------------------------------------------------------------ 13 GSC01599-00 WFPC2 IMAGE WFALL-F F675W ATD-GAIN=7 1 50S 138 IX ------------------------------------------------------------------------------------------------------------------------------------ 14 GSC01599-00 WFPC2 IMAGE WFALL-F F555W ATD-GAIN=7 1 35S 138 IX ------------------------------------------------------------------------------------------------------------------------------------ 6787( 4) - 05/02/96 09:58 - [ 5] Summary Form for Proposal 6787 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ATD-GAIN=15 ATD-GAIN=7 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category HOT STARS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE F ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W F675W F656N ------------------------------------------------------------------------------------------------------------------------------------ Target Names PK050+03D1 HD179588 GSC01599-00138 ------------------------------------------------------------------------------------------------------------------------------------