! File: 1092C.PROP ! Database: PEPDB ! Date: 16-FEB-1994:01:21:47 coverpage: title_1: ECLIPSES OF CATACLYSMIC VARIABLE STARS sci_cat: STELLAR ASTROPHYSICS proposal_for: GTO/HSP pi_fname: ROBERT pi_mi: C. pi_lname: BLESS pi_inst: WISCONSIN, UNIVERSITY OF pi_country: USA keywords_1: CATACLYSMIC VARIABLE STARS hours_pri: 46.00 num_pri: 2 time_crit: X ! end of coverpage abstract: line_1: The cataclysmic variables are close binary stars consisting of a late-type line_2: star and white dwarf. Mass is being transferred from the late-type star to the line_3: white dwarf. Unless the white dwarf has an extremely strong magnetic field, the line_4: transferred mass forms an accretion disk around the white dwarf. An important line_5: reason to observe the cataclysmic variables is that they provide an unparalled line_6: way to study nearly all aspects of the accretion of gas onto compact objects. line_8: We propose to observe the eclipses of several cataclysmic variables. The line_9: eclipse light curves can be used to find information about the geometry and line_10: physical conditions in the accretion disk. One star we propose to observe, Z line_11: Cha, is a dwarf nova. Eclipse observations of this star will provide line_12: information about changes in the structure of the accretion disk over the line_13: outburst cycle. line_14: Revision History: Received on RPS 9/1/89; Added to SCCS 9/5/89 line_15: Updated V2 prop instr; RPSS V7.2 remote & local; fixed typos; Added line_16: data-fmt; added period & zero-phase uncertainties - SALM 9/7/89 line_17: Text changes; ACQ added to repeat visits - SALM 9/28/89; Move 1 targ line_18: to cycle2, spread out repeats - SALM 2/14/90; Added ACQ to repeat visits line_19: - SALM 6/27/90; Revised cycle 1 time--BJW 2/27/91; Split proposal by cycle-- line_20: BJW 3/20/91; Split up observations of Z Cha--BJW 9/6/91; ! ! end of abstract general_form_proposers: lname: ROBINSON fname: EDWARD mi: L. inst: TEXAS, UNIVERSITY OF country: USA ! lname: BLESS fname: ROBERT mi: C. inst: WISCONSIN, UNIVERSITY OF country: USA ! lname: VAN CITTERS fname: G. mi: W. inst: NATIONAL SCIENCE FOUNDATION country: USA ! lname: DOLAN fname: JOSEPH mi: F. inst: NASA, GODDARD SPACE FLIGHT CENTER country: USA ! lname: WHITE fname: RICHARD mi: L. inst: SPACE TELESCOPE SCIENCE INSTITUTE country: USA ! lname: ELLIOT fname: JAMES mi: L. inst: MASSACHUSETTS INSTITUTE OF TECHNOLOGY country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: We propose to obtain high speed ultraviolet photometry of the two eclipsing line_2: cataclysmic variables Z Cha (orbital P = 1 hr. 47 min.) and V2051 Oph (orbital line_3: P = 1 hr. 30 min.). Z Cha is an erupting dwarf nova with outbursts line_4: approximately every 60 days; V2051 Oph is a nova-like variable which does not line_5: erupt and will serve as a "control". We plan to obtain 20 observations of Z line_6: Cha, at approximately 3 day intervals, each observation lasting for two hours. line_7: Similarly, we plan to observe V2051 Oph at four times separated by one to line_8: three weeks during this same period. line_10: Cycle 1 ! question: 4 section: 1 line_1: The eclipses of the white dwarf and surrounding accretion disk by the late type line_2: secondary will have the greatest contrast in the ultraviolet where the peak line_3: flux is emitted. The functional dependance of disk temperature on radius line_4: reveals that observations at 1200 A probe a region of the disk 4 times closer line_5: to the white dwarf than observations at 3500 A. Furthermore, accurate eclipse line_6: profiles can be obtained from ST, undistorted by transparency changes and line_7: scintillation noise, which affect ground based data. ! question: 13 section: 1 line_1: Multicolor ultraviolet photometry of the two eclipsing cataclysmic variables Z line_2: Cha (dwarf nova with orbital P = 1 hr. 47 min.) and V2051 Oph (nova-like with line_3: orbital P = 1hr. 30 min.) is proposed. A differential analysis of Z Cha in line_4: eruption, compared to V2051 Oph, will yield important clues as to the changes line_5: in the physical and geometric properties of accretion disks. ! !end of general form text general_form_address: lname: ROBINSON fname: EDWARD mi: L. category: CON inst: UNIVERSITY OF TEXAS addr_1: ASTRONOMY DEPARTMENT city: AUSTIN state: TX zip: 78712 country: USA phone: (512)471-4461 ! lname: BLESS fname: ROBERT mi: C. category: PI inst: UNIVERSITY OF WISCONSIN addr_1: WASHBURN OBSERVATORY addr_2: 475 N. CHARTER STREET city: MADISON state: WI zip: 53706 country: USA phone: (608)262-1715 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: Z-CHA descr_1: DWARF NOVA pos_1: RA = 8H 7M 28.155S +/- 0.8", pos_2: DEC = -76D 32' 0.67" +/- 0.5" equinox: 2000 pm_or_par: NO acqpr_1: COMP plate_req: NO comment_1: Z-CHA IS THE WESTERN COMPONENT OF comment_2: A CLOSE PAIR. comment_3: POSREF = ROBINSON. fluxnum_1: 1 fluxval_1: V = 14 +/- 3 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 0.500 targname: Z-CHA config: HSP/UV1 opmode: ACQ num_exp: 1 time_per_exp: 72S fluxnum_1: 1 priority: 2 param_1: DATA-FORMAT=WORD, req_1: ONBOARD ACQ FOR 1; req_2: CYCLE 1 / 0.5-2; comment_1: REPEAT VISITS REQUIRE A RE-ACQUISITION comment_2: OF EACH TARGET, UNTIL THE SYSTEM IS comment_3: CAPABLE OF RE-USING GUIDE STARS. ! linenum: 1.000 targname: Z-CHA config: HSP/UV1 opmode: SINGLE aperture: 1.0 sp_element: F135W num_exp: 1 time_per_exp: 45M fluxnum_1: 1 priority: 2 req_1: PHASE 0.8 +/- 0.05; req_2: PERIOD 0.074499219D +/- 0.000000005D; req_3: ZERO-PHASE JD2440264.6823 +/- 0.0005D; req_4: NON-INT / 1; req_5: REPEAT 0.5-1.0 EVERY 4D +/- 0.5D req_6: FOR 30 MORE TIMES; comment_1: EXPOSURE SHOULD COVER ENTIRE ECLIPSE. comment_2: OBSERVE FOR MAXIMUM TIME POSSIBLE comment_3: WITH ONE ORBIT. comment_4: FULL EPHEMERIS IS HJD 2440264.6823 comment_5: +0.074499219 E + 7.8 E-13 E**2. ! linenum: 1.500 targname: Z-CHA config: HSP/UV1 opmode: ACQ num_exp: 1 time_per_exp: 72S fluxnum_1: 1 priority: 2 param_1: DATA-FORMAT=WORD, req_1: ONBOARD ACQ FOR 2; comment_1: REPEAT VISITS REQUIRE A RE-ACQUISITION comment_2: OF EACH TARGET, UNTIL THE SYSTEM IS comment_3: CAPABLE OF RE-USING GUIDE STARS. ! linenum: 2.000 targname: Z-CHA config: HSP/UV1 opmode: SINGLE aperture: 1.0 sp_element: F135W num_exp: 1 time_per_exp: 45M fluxnum_1: 1 priority: 2 req_1: PHASE 0.4 +/- 0.05; req_2: PERIOD 0.074499219D +/- 0.000000005D; req_3: ZERO-PHASE JD2440264.6823 +/- 0.0005D; req_4: NON-INT / 2; req_5: REPEAT 1.5-2.0 EVERY 12D +/- 0.5D req_6: FOR 10 MORE TIMES; comment_1: EXPOSURE SHOULD COVER PRE-ECLIPSE comment_2: LIGHT CURVE. OBSERVE FOR MAXIMUM TIME comment_3: POSSIBLE WITH ONE ORBIT. comment_4: FULL EPHEMERIS IS HJD 2440264.6823 comment_5: +0.074499219 E + 7.8 E-13 E**2. ! ! end of exposure logsheet ! No scan data records found