7371( 6) - 01/14/99 09:06 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7371 Version: 6 Check-in Date: 14-Jan-1999 09:05:21 1.Proposal Title: The White Dwarf Luminosity Function in NGC 188 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Michael Bolte University of California CoI: Charles Claver Kitt Peak National Observatory N CoI: Greg Fahlman University of British Columbia N CoI: James Hesser Dominion Astrophysical Observatory N CoI: Jennifer Johnson University of California, Santa Cruz N CoI: Harvey Richer University of British Columbia N CoI: Peter B. Stetson Dominion Astrophysical Observatory N CoI: Don A. VandenBerg University of Victoria N CoI: Matt A. Wood Florida Institute of Technology N CoI: Howard Bond Space Telescope Science Institute Contact: N ------------------------------------------------------------------------------------ 5. Abstract We propose deep photometric observations of the old open cluster NGC 188 with three goals. ( i) From the termination of the white dwarf luminosity function (WDLF), estimate the age of the cluster and for the first time have an alternative to fitting stellar models to the main-sequence turnoff (MSTO). Tests of the MSTO-based ages for old clusters is crucial for sorting out the ``age of the Universe'' problem confronting cosmology. ( ii) Use the WDLF to test in detail certain aspects of cooling physics in WDs. Our NGC 188 data will be one of the first ``complete'' samples of WDs (in the sense of containing stars from the full cooling sequence) all at a known distance, with similar compositions and derived from a fairly well understood initial mass distribution. ( iii) Test the new generation of stellar interiors models for low-mass stars and provide a luminosity function of the cluster to masses below 0.1M_\odot. ------------------------------------------------------------------------------------ 7371( 6) - 01/14/99 09:06 - [ 2] Observations Description ------------------------ We have planned observations designed to reach the end of the 9 Gyr WD sequence with 0.2mag uncertainties in the colors in 4 non overlapping, contiguous fields in the center of NGC 188. The exposures are 4 x 1200 seconds in F814W in a BOX dither, 4 x 1200 seconds in F555W in the BOX dither plus an additional 1 x 1000 seconds in F555W. Real Time Justification ----------------------- We have found that having ground-based calibration of HST fields can be quite important for final photometry to be put on the standard system to < 0\\\\Mag02. We will support the HST observations with KPNO 0.9m and DAO 1.8m observations and establish field-to-field zeropoints based on ground observations. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7371( 6) - 01/14/99 09:06 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC188-1 STELLAR CLUSTER, OPEN RA=00H 48M .0S +/- 0.1S, DEC=85D J2000 V = 26.5 CLUSTER 13' 30" +/- 5", PLATE-ID=00A5 B-V = 0.6 Comments: THE TARGET FLUX LEVEL REFERS TO THE FAINT WHITE-DWARF STARS IN THE CLUSTER. 2 NGC188-2 STELLAR CLUSTER, OPEN RA=00H 48M .0S +/- 0.1S, DEC=85D J2000 V = 26.5 CLUSTER 16' 00" +/- 5", PLATE-ID=00A5 B-V = 0.6 Comments: THE TARGET FLUX LEVEL REFERS TO THE FAINT WHITE-DWARF STARS IN THE CLUSTER. 3 NGC188-3 STELLAR CLUSTER, OPEN RA=00H 46M .0S +/- 0.1S, DEC=85D J2000 V = 26.5 CLUSTER 16' 00" +/- 5", PLATE-ID=00A5 B-V = 0.6 Comments: THE TARGET FLUX LEVEL REFERS TO THE FAINT WHITE-DWARF STARS IN THE CLUSTER. 4 NGC188-4 STELLAR CLUSTER, OPEN RA=00H 46M .0S +/- 0.1S, DEC=85D J2000 V = 26.5 CLUSTER 13' 30" +/- 5", PLATE-ID=00A5 B-V = 0.6 Comments: THE TARGET FLUX LEVEL REFERS TO THE FAINT WHITE-DWARF STARS IN THE CLUSTER. 7371( 6) - 01/14/99 09:06 - [ 4] Visit: 01 Visit Priority: Visit Requirements: GROUP 1, 1A WITHIN 60D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC188-1 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1300 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC188-1 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1200 S POS TARG 0.5, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC188-1 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1300 S POS TARG 0.75, 0.75 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC188-1 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1400 S POS TARG 0.25, 0.5 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC188-1 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1300 S SAME POS AS 1 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC188-1 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1200 S POS TARG 0.5, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC188-1 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1300 S POS TARG 0.75, 0.75 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC188-1 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1400 S POS TARG 0.25, 0.5 ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC188-1 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1000 S ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC188-2 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1000 S ------------------------------------------------------------------------------------------------------------------------------------ 7371( 6) - 01/14/99 09:06 - [ 5] Visit: 02 Visit Priority: Visit Requirements: GROUP 2, 2A WITHIN 60D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 19 NGC188-3 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1300 S ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC188-3 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1200 S POS TARG 0.5, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 21 NGC188-3 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1300 S POS TARG 0.75, 0.75 ------------------------------------------------------------------------------------------------------------------------------------ 22 NGC188-3 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1400 S POS TARG 0.25, 0.5 ------------------------------------------------------------------------------------------------------------------------------------ 23 NGC188-3 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1300 S SAME POS AS 19 ------------------------------------------------------------------------------------------------------------------------------------ 24 NGC188-3 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1200 S POS TARG 0.5, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 25 NGC188-3 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1300 S POS TARG 0.75, 0.75 ------------------------------------------------------------------------------------------------------------------------------------ 26 NGC188-3 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1400 S POS TARG 0.25, 0.5 ------------------------------------------------------------------------------------------------------------------------------------ 27 NGC188-3 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1000 S ------------------------------------------------------------------------------------------------------------------------------------ 28 NGC188-4 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 900 S ------------------------------------------------------------------------------------------------------------------------------------ 7371( 6) - 01/14/99 09:06 - [ 6] Visit: 1A Visit Priority: Visit Requirements: SAME ORIENT AS 1 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC188-2 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1300 S ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC188-2 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1200 S POS TARG 0.5, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC188-2 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1300 S POS TARG 0.75, 0.75 ------------------------------------------------------------------------------------------------------------------------------------ 14 NGC188-2 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1400 S POS TARG 0.25, 0.5 ------------------------------------------------------------------------------------------------------------------------------------ 15 NGC188-2 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1300 S SAME POS AS 11 ------------------------------------------------------------------------------------------------------------------------------------ 16 NGC188-2 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1200 S POS TARG 0.5, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 17 NGC188-2 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1300 S POS TARG 0.75, 0.75 ------------------------------------------------------------------------------------------------------------------------------------ 18 NGC188-2 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1400 S POS TARG 0.25, 0.5 ------------------------------------------------------------------------------------------------------------------------------------ 7371( 6) - 01/14/99 09:06 - [ 7] Visit: 2A Visit Priority: Visit Requirements: SAME ORIENT AS 2 On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 29 NGC188-4 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1300 S ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC188-4 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1200 S POS TARG 0.5, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 31 NGC188-4 WFPC2 IMAGE WFALL F555W CR-SPLIT=NO 1 1300 S POS TARG 0.75, 0.75 ------------------------------------------------------------------------------------------------------------------------------------ 32 NGC188-4 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1400 S POS TARG 0.25, 0.5 ------------------------------------------------------------------------------------------------------------------------------------ 33 NGC188-4 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1300 S SAME POS AS 29 ------------------------------------------------------------------------------------------------------------------------------------ 34 NGC188-4 WFPC2 IMAGE WFALL F814W CR-SPLIT=NO 1 1400 S POS TARG 0.5, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 7371( 6) - 01/14/99 09:06 - [ 8] Summary Form for Proposal 7371 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFALL ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GROUP 1, 1A WITHIN 60D POS TARG 0.5, 0.25 POS TARG 0.75, 0.75 POS TARG 0.25, 0.5 SAME POS AS 1 GROUP 2, 2A WITHIN 60D SAME POS AS 19 SAME ORIENT AS 1 SAME POS AS 11 SAME ORIENT AS 2 SAME POS AS 29 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC188-1 NGC188-2 NGC188-3 NGC188-4 ------------------------------------------------------------------------------------------------------------------------------------