! Refer to the HST Phase II Proposal Instructions to fill this out ! ! Anything after a "!" is ignored, and may be deleted ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: Alice Berman ! Phone: 410 338-4462 , E-mail: aberman@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Date generated: Thu Dec 21 13:11:31 EST 1995 ! Filled in by Szkody Jan 11 1996 3rd pass, revised Feb 7 Proposal_Information ! Section 4 Title: The Identification and Cooling of the White Dwarf in the WZ Sge-Like System AL Com Proposal_Category: GO Scientific_Category: Binaries and Star Formation Cycle: 6 Investigators PI_name: Dr. Paula Szkody PI_Institution: University of Washington CoI_Name: Dr. Ed Sion CoI_Institution: Villanova Contact: N ! Y or N (designate at most one contact) CoI_Name: Steve Howell CoI_Institution: Planetary Science Institute Contact: N ! Y or N (designate at most one contact) CoI_Name: Dr.Warren Sparks CoI_Institution: Los Alamos National Lab Contact: N ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) We propose to obtain 3 FOS observations (one in 1996 Feb, one in April and one in June) in order to identify and measure the cooling of the white dwarf in the WZ Sge-like system AL Com, which underwent a long outburst in April-June 1995. Unlike most dwarf novae systems, which undergo outbursts on timescales of weeks to months and which last only days to 2 weeks at most, the recurrence for AL Com is 20 yrs and its outburst lasted 2 months. This is very similar to the system WZ Sge (recurrence of 33 yrs and outburst length of 4 months). The UV cooling of WZ Sge lasted for more than 3 yrs and enabled the determination of the heating and cooling properties of its highly unusual DAQZ white dwarf. Obtaining the cooling curve of AL Com in the 1150-2500Angstrom region will finally allow further tests of accretion heating in the regime of extremely low viscosity and mass transfer rate that exists in these very long timescale systems. In addition, we will be able to determine the temperature and type of white dwarf in comparison to the highly unusual one in WZ Sge. We have waited 17 yrs (since the 1978 outburst of WZ Sge) to find another comparable system. Questions ! Free format text (please update) Observing_Description: We will make 3 observations over the Feb-June interval. The first 2 will take place in Feb and April and will use 2 orbits of dark-time, and the third will take place in June and use 4 orbits of dark-time. Each will use the FOS/BL with G160L to obtain low resolution (4.6-10A) spectra from 1150-2510A. We used the known UV flux of WZ Sge at quiescence (2.5E-14 at 1500A) and scaled by the difference in optical magnitudes between WZ Sge and AL Com (4.5 mag = factor of 63) to estimate the quiescent flux of AL Com at 1500A will be about 4E-16. Using the value of S (at 1500A) and T (for 1 arcsec aperture) with this flux gives a count rate of 0.019 c/s/diode. With a correction factor of 1.37 for a count rate close to dark count yields a time of 97 min to reach a signal-to-noise of 9. This is the equivalent of 4 orbits of dark time (25 min/orbit). The first observation is expected to have a higher flux (by a factor of 4) and the second (by a factor of 2-3) so we will use 50 min (2 orbits) of integration. Real_Time_Justification: We need 3 observations separated by about half a year and before the object returns to UV quiescence. To fit these in before the sun constraints prevent observations (the end of July), we need the first observation in the beginning of Feb, the second in April and the third in June. In order to eliminate the effects of geocoronal Lyman alpha, we need to use the dark-time (shadow) portions for fitting. Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Program will begin earlier than normal Cycle 6 programs in order to catch AL Com during its cooling following its April 95 outburst. Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: AL-COM Alternate_Names: Description: STAR, DWARF NOVA Position: RA=12H 32M 25.86S +/- 0.02S, DEC=14D 20' 42.7" +/- 0.2", PLATE-ID=00G0 ! PLATE-ID=0000 Equinox: J2000.0 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux: V=20.0 +/- 0.5 B-V=0.1 +/- 0.2 F-CONT(1500)=8 +/- 4 E-16 Comments: ! This is a template for a single visit containing a single exposure ! Repeat exposure and visit blocks as needed Visits ! Section 6 Visit_Number: 1 Visit_Requirements: BETWEEN 1-FEB-96 AND 29-FEB-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 10 ! Section 6.5 Target_Name: AL-COM Config: FOS/BL Opmode: ACQ/BINARY Aperture: 4.3 Sp_Element: MIRROR Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 250S Special_Requirements: ONBOARD ACQ FOR 11 ! Section 7.2 Comments: Exposure_Number: 11 ! Section 6.5 Target_Name: AL-COM Config: FOS/BL Opmode: RAPID Aperture: 1.0-PAIR-A Sp_Element: G160L Wavelength: 1150-2510 Optional_Parameters: READ-TIME=60 Number_of_Iterations: 1 Time_Per_Exposure: 66.0M Special_Requirements: Visit_Number: 2 Visit_Requirements: BETWEEN 1-APR-96 AND 30-APR-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 20 ! Section 6.5 Target_Name: AL-COM Config: FOS/BL Opmode: ACQ/BINARY Aperture: 4.3 Sp_Element: MIRROR Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 370S Special_Requirements: ONBOARD ACQ FOR 21 ! Section 7.2 Exposure_Number: 21 ! Section 6.5 Target_Name: AL-COM Config: FOS/BL Opmode: RAPID Aperture: 1.0-PAIR-A Sp_Element: G160L Wavelength: Optional_Parameters: READ-TIME=60 STEP-PATT=SINGLE Number_of_Iterations: 1 Time_Per_Exposure: 66.0M Special_Requirements: ! Section 7.2 Visit_Number: 3 Visit_Requirements: BETWEEN 1-JUN-96 AND 30-JUN-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 30 ! Section 6.5 Target_Name: AL-COM Config: FOS/BL Opmode: ACQ/BINARY Aperture: 4.3 Sp_Element: MIRROR Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 370S Special_Requirements: ONBOARD ACQ FOR 31 Exposure_Number: 31 ! Section 6.5 Target_Name: AL-COM Config: FOS/BL Opmode: RAPID Aperture: 1.0-PAIR-A Sp_Element: G160L Wavelength: Optional_Parameters: READ-TIME=60 STEP-PATT=SINGLE Number_of_Iterations: 1 Time_Per_Exposure: 155.0M Special_Requirements: EXPAND ! Section 7.2 Visit_Number: 4 Visit_Requirements: BETWEEN 1-FEB-96 AND 29-FEB-96 On_Hold_Comments: Visit_Comments: Exposure_Number: 10 ! Section 6.5 Target_Name: AL-COM Config: FOS/BL Opmode: ACQ/BINARY Aperture: 4.3 Sp_Element: MIRROR Wavelength: Optional_Parameters: Number_of_Iterations: 1 Time_Per_Exposure: 250S Special_Requirements: ONBOARD ACQ FOR 11 ! Section 7.2 Comments: Exposure_Number: 11 ! Section 6.5 Target_Name: AL-COM Config: FOS/BL Opmode: RAPID Aperture: 1.0-PAIR-A Sp_Element: G160L Wavelength: 1150-2510 Optional_Parameters: STEP-PATT=SINGLE READ-TIME=60 Number_of_Iterations: 1 Time_Per_Exposure: 66.0M Special_Requirements: Data_Distribution ! Defaults indicated; change if desired Medium: 8MM ! 8MM or 6250BPI or 1600BPI Blocking_Factor: 10 ! 10 or 1 ! Only astronomers with very old 9- ! track tape drives should consider ! a blocking factor of 1 Ship_To: PI_Address ! STSCI or PI_Address or ! PI Address from Phase I is: ! ! Department of Astronomy ! Box 351580 ! Seattle WA ! 98195 ! ! Ship_Via: UPS ! UPS (2-day) or OVERNIGHT ! Overnight shipping done at PI expense Recipient_Email: ! Needed if Ship_To: is not PI_Address ! ! Let us know what you think of this template and software! ! Please send a list of your likes and dislikes to your Program Coordinator