! File: 4945C.PROP ! Database: PEPDB ! Date: 23-FEB-1994:11:46:32 coverpage: title_1: PERIODIC VARIATIONS IN DQ HERCULIS STARS - CYC2HIGH sci_cat: STELLAR ASTROPHYSICS sci_subcat: SUBLUMINOUS STARS proposal_for: GTO/HSP cont_id: 1090 pi_fname: ROBERT pi_mi: C. pi_lname: BLESS pi_inst: WISCONSIN, UNIVERSITY OF pi_country: USA pi_phone: (608) 262-1715 keywords_1: CATACLYSMIC VARIABLE STARS hours_pri: 5.67 num_pri: 9 ! end of coverpage abstract: line_1: The DQ Herculis Stars are cataclysmic variables line_2: showing rapid, strictly periodic luminosity line_3: variations at either optical or X-ray wavelengths, line_4: and usually both. The periods range from 33 sec in line_5: AE AQR through 71 sec in DQ Her to 18690 sec in TV line_6: Col. The cataclysmic variables are all close binary line_7: stars consisting of a late-type star transferring line_8: mass to its companion white dwarf star. The white line_9: dwarf in the DQ Her stars is magnetized. The line_10: periodicities of the DQ Her stars are caused by line_11: rotation of the magnetized, acreting white dwarf. We line_12: propose to observe the DQ Her stars at ultraviolet line_13: wavelengths using the high speed photometer on the line_14: space telescope. The purpose of the observations is line_15: to investigate the physics of accretion onto compact line_16: stars. Revision History: Received on RPS 9/1/89; line_17: Added to SCCS 9/5/89 RPSS V7.2 remote & local; Typos line_18: corrected; Added data-fmt - SALM 9/7/89 Updated text line_19: - SALM 9/28/89; Moved 5 targ to cycle 2 - SALM line_20: 2/12/90 Switched 1 targ in cycles 1 & 2 - SALM ! ! end of abstract general_form_proposers: lname: WHITE fname: RICHARD mi: L. inst: SPACE TELESCOPE SCIENCE INSTITUTE country: USA ! lname: BLESS fname: ROBERT mi: C. inst: WISCONSIN, UNIVERSITY OF country: USA ! lname: DOLAN fname: JOSEPH mi: F. inst: NASA, GODDARD SPACE FLIGHT CENTER country: USA ! lname: ELLIOT fname: JAMES mi: L. inst: MASSACHUSETTS INSTITUTE OF TECHNOLOGY country: USA ! lname: ROBINSON fname: EDWARD mi: L. inst: TEXAS, UNIVERSITY OF country: USA ! lname: VAN CITTERS fname: G. mi: W. inst: NATIONAL SCIENCE FOUNDATION country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: The phases and amplitudes of the pulsations of the line_2: DQ Her stars usually vary with orbital phase. It is line_3: critically important to know how they vary to line_4: interpret the pulsations properly. Observations over line_5: at least one entire orbit are necessary to define line_6: these variations, and, since each star is different, line_7: all the stars should be observed. Therefore, we will line_8: observe each of the DQ Her stars (except AE Aqr, line_9: whose orbital period is exceptionally long) for a line_10: length of time equal to one orbital period. The line_11: total observing time will be 35 hours. The line_12: appropriate filters to use are the continuum filters line_13: at 1350 A and 2400 A in the prism pair of filters, line_14: and the appropriate integration times are 1/2 second line_15: per pair. Cycle 0: 1 Cycle 1: remainder ! question: 4 section: 1 line_1: The periodic variations exhibited by the DQ Herculis line_2: stars in the optical regime may be of a line_3: substantially larger amplitude in the ultraviolet line_4: region accessible for ST. The funneling of the line_5: accretion flows onto the magnetic poles produces line_6: regions which are substantially hotter, and thus line_7: more luminous, in the ultraviolet than accretion line_8: processes in the absence of fields. The ultraviolet line_9: photometry may also actually detect the presence of line_10: the underlying white dwarf as well. ! question: 13 section: 1 line_1: A program of high speed ultraviolet photometry of line_2: the DQ Herculis stars (the intermediate polars) is line_3: proposed to search for the ultraviolet counterparts line_4: of the rapid, periodic variations previously seen in line_5: the optical and X-ray regions. The observations will line_6: help to outline the process of viscous accretion in line_7: the presence of strong magnetic fields. ! !end of general form text general_form_address: lname: ROBINSON fname: EDWARD mi: L. category: CON inst: UNIVERSITY OF TEXAS addr_1: DEPARTMENT OF ASTRONOMY city: AUSTIN state: TX zip: 78712 country: USA phone: (512) 471-3401 ! 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: DQ-HER descr_1: VARIABLE STAR descr_2: INTERACTING BINARY pos_1: RA = 18H 7M 30.22S +/- .5", pos_2: DEC = +45D 51' 30.9" +/- .5" equinox: 2000 pm_or_par: NO plate_req: NO comment_1: POSREF = ROBINSON fluxnum_1: 1 fluxval_1: V = 16 +/- 1 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.500 targname: DQ-HER 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 ACQUISITION FOR 2; req_2: CYCLE 3 / 1.5-2; req_3: PCS MODE FINE / 1.500-2.000; ! linenum: 2.000 targname: DQ-HER config: HSP/UV1 opmode: SINGLE aperture: 1.0 sp_element: F220W num_exp: 1 time_per_exp: 4.7H fluxnum_1: ^ priority: ^ param_1: SAMPLE-TIME=0.07, comment_1: FOR LINES 1.5-2, GAPS DUE TO EARTH comment_2: OCCULTATION SHOULD BE MINIMIZED. ! ! end of exposure logsheet ! No scan data records found