! File: 1093C.PROP ! Database: PEPDB ! Date: 16-FEB-1994:01:24:24 coverpage: title_1: OBSERVATIONS OF ZZ CETI STARS sci_cat: STELLAR ASTROPHYSICS proposal_for: GTO/HSP cont_id: 1093 pi_fname: ROBERT pi_mi: C. pi_lname: BLESS pi_inst: WISCONSIN, UNIVERSITY OF pi_country: USA pi_phone: (608) 262-1715 keywords_1: PULSATING WHITE DWARFS hours_pri: 7.04 num_pri: 1 ! end of coverpage abstract: line_1: The ZZ Ceti Stars are pulsating DA white dwarfs with line_2: temperatures near 11,000K. They are all pulsating line_3: in the non-radial g-modes, and are multi-periodic line_4: with periods between 200 sec and 1200 sec. Two major line_5: uncertainties about the ZZ Ceti stars are first, the line_6: exact temperature limits of the ZZ Ceti instability line_7: strip, and second, whether the luminosity variations line_8: are entirely due to temperature variations - as they line_9: should be if the pulsations are g-mode pulsations. line_10: We propose to observe the ZZ Ceti stars with the line_11: high speed photometer to measure their mean colors line_12: (and thus mean temperatures) and their color line_13: variations (and thus their temperature variations). line_14: Revision History: Received on RPS 9/1/89; Added to line_15: SCCS 9/5/89 Updated to V2 prop instr; RPSS V7.2 line_16: remote & local; Added data-fmt - SALM 9/7/89; Text line_17: changes - SALM 9/28/89; Reduce Texp to 6H - SALM line_18: 2/14/90 MJN 3/20/92 - removed prism mode and moved line_19: observation to UV2. Split observation to two 3 hour line_20: runs in the F184W and F284M filters. ! ! 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 measure the ultraviolet colors line_2: (lambda-lambda-1850, 2700 A) of the ZZ Ceti star, line_3: G117-B15A over its pulsation cycle (P = 215.2 s) line_4: with high accuracy. Simultaneous two-color line_5: ultraviolet photometry is planned using the HSP. In line_6: order to measure the photometric variations with line_7: high precision, we need to observe G117-B15A (B = line_8: 15.5 +/- 0.2 mag) for 10 hours, sampling at one line_9: second intervals. The high speed photometer is the line_10: optimum instrument for this project and G117-G15A is line_11: the prime ZZ Ceti candidate owing to the extreme line_12: stability of its pulsation period and the relative line_13: simplicity of its light curve. Cycle 1 ! question: 4 section: 1 line_1: The temperatures and temperature variations of the line_2: ZZ Ceti stars can only be reliably measured at the line_3: ultraviolet wavelengths accessible to ST. Absolute line_4: temperature determinations for lambda > 4500 A have line_5: large uncertainties (+/- 500 K) due both to line_6: contamination of the optical region (lambda-lambda line_7: 4000 - 6000 A) by Balmer lines and continuum and the line_8: temperature insensitivity of working on the line_9: Rayleigh-Jeans tail of the energy distribution. It line_10: is estimated that a five-fold improvement in the line_11: temperature determinations would result from ST line_12: observations. ! question: 13 section: 1 line_1: Ultraviolet high speed photometry is proposed for line_2: G116-B15 A, a remarkably stable ZZ Ceti star (P = line_3: 215.2 sec) in order to precisely determine mean line_4: ultraviolet colors (mean temperatures) and color line_5: variations (temperature variations). ! !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)471-4461 ! 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: G117-B15A descr_1: ZZ CETI STAR pos_1: RA = 9H 24M 15.35S +/- 0.4", pos_2: DEC = +35D 16' 51.0" +/- 0.4" equinox: J2000 acqpr_1: COMP plate_req: NO comment_1: G117-B15A HAS A CPM COMPANION AT comment_2: 13.4" DISTANCE WITH A POSITION comment_3: ANGLE OF 123 DEGREES. comment_4: POSREF = ROBINSON. fluxnum_1: 1 fluxval_1: V=15.5+/-.2 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 0.500 targname: G117-B15A config: HSP/UV2 opmode: ACQ num_exp: 1 time_per_exp: 60S fluxnum_1: 1 priority: 1 param_1: DATA-FORMAT=WORD, req_1: ONBOARD ACQ FOR 1; req_2: CYCLE 2 / 0.5-4; req_3: PCS MODE FINE / 0.5-4; ! linenum: 1.000 targname: G117-B15A config: HSP/UV2 opmode: SINGLE aperture: 1.0 sp_element: F145M num_exp: 1 time_per_exp: 1.5H fluxnum_1: 1 priority: 1 param_1: SAMPLE-TIME=0.05 comment_1: FOR LINE 1, GAPS DUE TO EARTH comment_2: OCCULTATION SHOULD BE MINIMIZED. ! linenum: 1.500 targname: G117-B15A config: HSP/UV2 opmode: ACQ num_exp: 1 time_per_exp: 60S fluxnum_1: 1 priority: 1 param_1: DATA-FORMAT=WORD, req_1: ONBOARD ACQ FOR 2; ! linenum: 2.000 targname: G117-B15A config: HSP/UV2 opmode: SINGLE aperture: 1.0 sp_element: F145M num_exp: 1 time_per_exp: 1.5H fluxnum_1: 1 priority: 1 param_1: SAMPLE-TIME=0.05 comment_1: FOR LINE 1, GAPS DUE TO EARTH comment_2: OCCULTATION SHOULD BE MINIMIZED. ! linenum: 2.500 targname: G117-B15A config: HSP/UV2 opmode: ACQ num_exp: 1 time_per_exp: 60S fluxnum_1: 1 priority: 1 param_1: DATA-FORMAT=WORD, req_1: ONBOARD ACQ FOR 3; ! linenum: 3.000 targname: G117-B15A config: HSP/UV2 opmode: SINGLE aperture: 1.0 sp_element: F184W num_exp: 1 time_per_exp: 1.5H fluxnum_1: 1 priority: 1 param_1: SAMPLE-TIME=0.05 comment_1: FOR LINE 1, GAPS DUE TO EARTH comment_2: OCCULTATION SHOULD BE MINIMIZED. ! linenum: 3.500 targname: G117-B15A config: HSP/UV2 opmode: ACQ num_exp: 1 time_per_exp: 60S fluxnum_1: 1 priority: 1 param_1: DATA-FORMAT=WORD, req_1: ONBOARD ACQ FOR 4; ! linenum: 4.000 targname: G117-B15A config: HSP/UV2 opmode: SINGLE aperture: 1.0 sp_element: F184W num_exp: 1 time_per_exp: 1.5H fluxnum_1: 1 priority: 1 param_1: SAMPLE-TIME=0.05 comment_1: FOR LINE 1, GAPS DUE TO EARTH comment_2: OCCULTATION SHOULD BE MINIMIZED. ! ! end of exposure logsheet ! No scan data records found