! $Id: 5315,v 24.1 1995/06/05 15:35:41 pepsa Exp $ coverpage: title_1: THE SEAT OF STELLAR-WIND INSTABILITIES: CYCLE4 MEDIUM sci_cat: HOT STARS sci_subcat: MASSIVE STARS proposal_for: GO pi_fname: IAN pi_mi: D. pi_lname: HOWARTH pi_inst: UNIVERSITY COLLEGE LONDON pi_country: UK pi_phone: 01044-71-387-7050 hours_pri: 2.17 num_pri: 1 hrs: Y time_crit: Y off_fname: BRIAN off_lname: MARTIN off_title: PROFESSOR off_inst: 8090 off_addr_1: DEPT. PHYSICS AND ASTRONOMY off_addr_2: UNIVERSITY COLLEGE LONDON off_addr_3: GOWER STREET off_city: LONDON off_zip: WC1E 6BT off_country: UK off_phone: 01044-71-387-7050 ! end of coverpage abstract: line_1: IUE observations have established that high-velocity variability in UV line_2: P-Cygni profiles is a fundamental property of radiatively-driven line_3: winds, and that this variability is a signature of the line-driven line_4: instability. It is unclear, however, whether the variability is line_5: completely intrinsic to the flow, or if it requires a perturbing line_6: `seed' from the low-velocity regime. IUE observations lack adequate line_7: signal/noise to address this problem; existing HST results are line_8: ambiguous. We propose to obtain high-quality time-series HRS line_9: spectroscopy of 68 Cygni, a star extensively observed with IUE, in line_10: order to provide an empirical answer to this question. These data line_11: will distinguish between low-velocity, mechanically-driven line_12: instabilities and intrinsic, radiatively-driven instabilities, and line_13: will define the interaction of the two regimes. The results will, in line_14: turn, have wider implications for the applicability of steady-state line_15: wind models, and will provide basic constraints on our radiation hydro line_16: code. ! ! end of abstract general_form_proposers: lname: HOWARTH fname: IAN mi: D. inst: 8090 country: UK esa: Y ! lname: OWOCKI fname: STAN mi: P. inst: 1845 country: USA ! lname: PRINJA fname: RAMAN mi: K. inst: 8090 country: UK esa: Y ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: In order to monitor short-timescale (hour) variability in line_2: stellar-wind outflows, the P-Cygni profiles of NV (1240A), line_3: SiIV (1400A) and CIV (1550A) are to be observed in the line_4: spectrum of HD203064 once every orbit for 19 orbits, at line_5: high S/N, with the G160M grating. ! question: 4 section: 1 line_1: Only HST can provide the necessary high S/N in the UV resonance line_2: lines of interest. ! question: 5 section: 1 line_1: The prime driver for this programme is to obtain adequately sampled line_2: time-series spectra over the maximum likely development time for line_3: a `discrete absorption component' in the stellar wind. "Adequately line_4: sampled" implies an absolute minimum frequency of once per orbit, line_5: while the maximum recurrence time is about 25 hours. line_6: The observations should therefore be scheduled to take place line_7: once per orbit for 19 consecutive orbits, a bare minimum sampling line_8: rate for a length of time certain to catch at least one event. ! question: 6 section: 1 line_1: None ! ! question: 8 section: 1 line_1: Advance notification of scheduling will allow co-ordinated ground- line_2: based spectroscopy to be arranged. ! question: 9 section: 1 line_1: We have used data from the science verification phase, in combination line_2: with IUE spectra, to study variability in P-Cygni profiles of Zeta line_3: Oph. Those data show no discrete features at velocities of less than line_4: about 1100 km/s, supporting a purely intrinsic origin for wind line_5: variability. However, this behaviour appears to be different to that line_6: seen in Xi Per, which is more closely similar to 68 Cyg. Xi Per and line_7: Zeta Oph are the only two stars for which HST data suited to the study line_8: of low-velocity variable features are available to us. In neither case line_9: is the time sampling adequate, and there are no time series line_10: observations with suitable sampling in the archive. ! question: 10 section: 1 line_1: Extensive interactive data-analysis capabilities through the major line_2: Starlink node sited at UCL (both Unix and VMS machines), plus usual line_3: `well-founded laboratory' facilities. The UCL O-star group currently line_4: consists of one staff member (IDH), one research fellow (RKP), two line_5: research assistants, and two postgrad students. Manpower at about this line_6: level is expected to be maintained for the foreseeable future, and line_7: will be drawn on as necessary for the analysis of the HST data. line_9: The group at Bartol includes one associate professor (SPO), two line_10: research scientists (Alex Fullerton and Ken Gayley), and two graduate line_11: students (Glenn Cooper and Steven Cranmer). Owocki has worked line_12: extensively on the theory of the wind instabilty, and developed the line_13: radiation hydrodynamics code to simulate its nonlinear evolution. This line_14: code is run on remote Crays accessed via Internet to Bartol's local line_15: VMS/VAX cluster. Fullerton has done extensive observations of optical line_16: line variability in O stars, and Gayley works on theory of line line_17: transfer in hot-star winds. Cooper is currently completing a Ph.D line_18: thesis on X-ray emission from instability-driven shocks, and Cranmer line_19: is beginning a thesis aimed at exploring the effect of rotation on line_20: the formation of unstable wind structure. ! !end of general form text general_form_address: lname: HOWARTH fname: IAN mi: D. category: PI inst: 8090 addr_1: DEPT. PHYSICS AND ASTRONOMY addr_2: UNIVERSITY COLLEGE LONDON addr_3: GOWER STREET city: LONDON zip: WC1E 6BT country: UK phone: 01044-71-387-7050 telex: (SPAN) 19752::IDH ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: HD210839 name_2: LAMBACEP descr_1: A,105 pos_1: RA = 22H 11M 30.6S +/- 0.01S, pos_2: DEC = +59D 24' 52.1" +/- 0.1" equinox: J2000 fluxnum_1: 1 fluxval_1: V = 5.04 +/- 0.02, TYPE=O6I fluxnum_2: 1 fluxval_2: B-V = +0.25 +/- 0.01 fluxnum_3: 2 fluxval_3: E(B-V) = 0.55 +/- 0.03 fluxnum_4: 3 fluxval_4: F-CONT(1240) = 1.0 +/- 0.2 E-10 fluxnum_5: 4 fluxval_5: F-CONT(1400) = 1.2 +/- 0.2 E-10 fluxnum_6: 5 fluxval_6: F-CONT(1550) = 1.5 +/- 0.2 E-10 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: HD210839 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-A2 time_per_exp: 4.5S priority: 1 param_1: SEARCH-SIZE=3, param_2: BRIGHT=RETURN, param_3: LOCATE=YES, req_1: CYCLE 4; req_2: ONBOARD ACQ for 9-11; req_3: GROUP 9-22 WITHIN 4D; ! linenum: 2.000 sequence_1: DEFINE sequence_2: ORBIT targname: # config: HRS opmode: ACCUM aperture: # sp_element: G160M wavelength: 1398 num_exp: 1 time_per_exp: 545S s_to_n: 100 fluxnum_1: 4 priority: 1 param_1: FP-SPLIT=FOUR param_2: COMB=FOUR param_3: STEP-PATT=5 param_4: DOPPLER=ON req_1: CYCLE 4; ! linenum: 3.000 sequence_1: DEFINE sequence_2: ORBIT targname: # config: HRS opmode: ACCUM aperture: # sp_element: G160M wavelength: 1240 num_exp: 1 time_per_exp: 545S s_to_n: 100 fluxnum_1: 3 priority: 1 param_1: FP-SPLIT=FOUR param_2: COMB=FOUR param_3: STEP-PATT=5 param_4: DOPPLER=ON req_1: CYCLE 4; ! linenum: 4.000 sequence_1: DEFINE sequence_2: ORBIT targname: # config: HRS opmode: ACCUM aperture: # sp_element: G160M wavelength: 1398 num_exp: 1 time_per_exp: 545S s_to_n: 100 fluxnum_1: 4 priority: 1 param_1: FP-SPLIT=FOUR param_2: COMB=FOUR param_3: STEP-PATT=5 param_4: DOPPLER=ON req_1: CYCLE 4; ! linenum: 5.000 sequence_1: DEFINE sequence_2: ORBIT targname: # config: HRS opmode: ACCUM aperture: # sp_element: G160M wavelength: 1549 num_exp: 1 time_per_exp: 436S s_to_n: 100 fluxnum_1: 5 priority: 1 param_1: FP-SPLIT=FOUR param_2: COMB=FOUR param_3: STEP-PATT=5 param_4: DOPPLER=ON req_1: CYCLE 4; ! linenum: 6.000 sequence_1: DEFINE sequence_2: ORBIT targname: # config: HRS opmode: ACCUM aperture: # sp_element: G160M wavelength: 1398 num_exp: 1 time_per_exp: 545S s_to_n: 100 fluxnum_1: 4 priority: 1 param_1: FP-SPLIT=FOUR param_2: COMB=FOUR param_3: STEP-PATT=5 param_4: DOPPLER=ON req_1: CYCLE 4; ! linenum: 7.000 sequence_1: DEFINE sequence_2: ORBIT targname: # config: HRS opmode: ACCUM aperture: # sp_element: G160M wavelength: 1240 num_exp: 1 time_per_exp: 545S s_to_n: 100 fluxnum_1: 3 priority: 1 param_1: FP-SPLIT=FOUR param_2: COMB=FOUR param_3: STEP-PATT=5 param_4: DOPPLER=ON req_1: CYCLE 4; ! linenum: 8.000 sequence_1: DEFINE sequence_2: ORBIT targname: # config: HRS opmode: ACCUM aperture: # sp_element: G160M wavelength: 1398 num_exp: 1 time_per_exp: 545S s_to_n: 100 fluxnum_1: 4 priority: 1 param_1: FP-SPLIT=FOUR param_2: COMB=FOUR param_3: STEP-PATT=5 param_4: DOPPLER=ON req_1: CYCLE 4; ! linenum: 9.0 sequence_1: USE sequence_2: ORBIT targname: HD210839 aperture: 2.0 linenum: 10 sequence_1: USE sequence_2: ORBIT targname: HD210839 aperture: 2.0 linenum: 11 sequence_1: USE sequence_2: ORBIT targname: HD210839 aperture: 2.0 linenum: 12.500 targname: HD210839 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-A2 time_per_exp: 4.5S priority: 1 param_1: SEARCH-SIZE=3, param_2: BRIGHT=RETURN, param_3: LOCATE=YES, req_1: CYCLE 4; req_2: ONBOARD ACQ for 13-15; req_3: AFTER 11 by 8H; linenum: 13. sequence_1: USE sequence_2: ORBIT targname: HD210839 aperture: 2.0 linenum: 14. sequence_1: USE sequence_2: ORBIT targname: HD210839 aperture: 2.0 linenum: 15.0 sequence_1: USE sequence_2: ORBIT targname: HD210839 aperture: 2.0 linenum: 16.500 targname: HD210839 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-A2 time_per_exp: 4.5S priority: 1 param_1: SEARCH-SIZE=3, param_2: BRIGHT=RETURN, param_3: LOCATE=YES, req_1: CYCLE 4; req_2: ONBOARD ACQ for 17-19; req_3: AFTER 15 by 8H; linenum: 17.0 sequence_1: USE sequence_2: ORBIT targname: HD210839 aperture: 2.0 linenum: 18.0 sequence_1: USE sequence_2: ORBIT targname: HD210839 aperture: 2.0 linenum: 19.0 sequence_1: USE sequence_2: ORBIT targname: HD210839 aperture: 2.0 linenum: 20.500 targname: HD210839 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-A2 time_per_exp: 4.5S priority: 1 param_1: SEARCH-SIZE=3, param_2: BRIGHT=RETURN, param_3: LOCATE=YES, req_1: CYCLE 4; req_2: ONBOARD ACQ for 21-22; req_3: AFTER 19 by 8H; linenum: 21.0 sequence_1: USE sequence_2: ORBIT targname: HD210839 aperture: 2.0 linenum: 22.0 sequence_1: USE sequence_2: ORBIT targname: HD210839 aperture: 2.0 ! ! end of exposure logsheet ! No scan data records found