10146( 4) - 03/30/05 11:44 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 10146 Version: 4 Check-in Date: 30-Mar-2005 16:42:49 1.Proposal Title: Solving the problem of the White Dwarf Cooling Sequence End in M4: an efficent approach ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle 4. Parallel Pointing Tolerance GO 13 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Luigi R. Bedin Universita di Padova CoI: Dr. Maurizio Salaris Liverpool John Moores University N CoI: Prof. Giampaolo Piotto Universita di Padova Y CoI: Dr. Jay Anderson Rice University N CoI: Dr. Yazan Momany Universita di Padova N CoI: Dr. Francesca De Angeli Universita di Padova N CoI: Dr. Santi Cassisi INAF, Osservatorio Astronomico di Teramo N CoI: Dr. Ivan R. King University of Washington N ------------------------------------------------------------------------------------ 6. Abstract The end of the white dwarf (WD) cooling sequence (WDCS) has never been observed, despite the importance that it has in providing an age estimate of old stellar systems, independent from the standard method of the main sequence turn off. The best targets for this investigation are the closest stellar clusters, and, among them, globular clusters are the most interesting ones. Being the oldest stellar aggregates, they allow to probe the advanced WD cooling phases, and the independent age estimate coming from the end of their WDCS has an important cosmological impact. M4 is the best target for this investigation. Despite huge observational efforts, we still miss the end of its WDCS. The ACS camera offers a unique opportunity to identify it. Coupled with already existing observations, we here prove that we can finally reach it with only 10 HST orbits. This is probably the last opportunity we have for a large number of years. The data we are requesting here, will also be used to complete other two programs of great astrophysical impact: the observational detection of the main sequence hydrogen burning limit, and the measurement of the geometrical distance of M4. ------------------------------------------------------------------------------------ 10146( 4) - 03/30/05 11:44 - [ 2] Observations Description ------------------------ The observation has been organized in 5 visits during which 20 long exposures in F606W will be collected with LOW SKY. Also 2 short exposures, in each F606W, and F775W filters will be taken, using as much as possible of the not-low-sky part of the orbit. We need these short exposure to get the luminosity of the TO and the HB stars in the same photometric system. These numbers are fundamental because will allow us to get the age of the cluster which will be compared directely with those derived from the WDs. These short exposures will also help achiving the secondary program of our proposal (namely the geometrical distance of M4, and the parallax relative to the Galactic Bulge). The 5 visists have two different orientations. This is in order to match as maximum as possible the previous deep observations. The perfect match with previous observations, not only will allow to get the color informations, but also to separe the background and foreground objects from the real cluster members (Bedin et al. 2001, Bedin et al. 2003). The dither within each visit has been choosen according to Anderson and King (2000, PASP, 112, 1360). Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10146( 4) - 03/30/05 11:44 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 JUL02IMAGE01 STELLAR CLUSTER, RA=16H23M41.8900S +/- 0.1", J2000 V = 15.6+/-0.3 011 GLOBULAR CLUSTER DEC=-26D30'28.24" +/- 0.1", PLATE-ID=02J6 Coordinate Source: GSC_SURVEY_PLATE 11 JUN03IMAGE03 STELLAR CLUSTER, RA=16H23M41.7000S +/- 0.1", J2000 V = 15.6+/-0.3 011 GLOBULAR CLUSTER DEC=-26D30'25.79" +/- 0.1", PLATE-ID=02J6 Coordinate Source: GSC_SURVEY_PLATE Comments: ok 10146( 4) - 03/30/05 11:44 - [ 4] Visit: 01 Visit Priority: Visit Requirements: ORIENT 91.7839D TO 91.7839 D On Hold Comments: Additional Comments: NOTEs: This visit contains 1 short exposure and 4 long exposures in filter F606W. There are two different pointings, each at a different orbit to save time. The long exposure are taken imposing LOW SKY The orientation is that of target IMAGE01011. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0, 0; LOW-SKY; 1011 SEQ 1-2 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0, 0; LOW-SKY 1011 ------------------------------------------------------------------------------------------------------------------------------------ 3 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 0.5 S POS TARG 0.175, 0.175; 1011 SEQ 3-5 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 4 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0.175, 0.175; 1011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ 5 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0.175, 0.175; 1011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ JUL02IMAGE01011 1 ACS/WFC ACCUM WFC F606W none none none none 1 N/A JUL02IMAGE01011 2 ACS/WFC ACCUM WFC F606W none none none none 1 N/A JUL02IMAGE01011 3 ACS/WFC ACCUM WFC F606W none none none none 2 N/A JUL02IMAGE01011 4 ACS/WFC ACCUM WFC F606W none none none none 2 N/A JUL02IMAGE01011 5 ACS/WFC ACCUM WFC F606W none none none none 2 N/A 10146( 4) - 03/30/05 11:44 - [ 5] Visit: 02 Visit Priority: Visit Requirements: ORIENT 91.7839D TO 91.7839 D On Hold Comments: Additional Comments: NOTEs: This visit contains 1 mid exposure and 4 long exposure in filter F606W. There are two different pointings, each at a different orbit to save time. The long exposure are taken imposing LOW SKY The orientation is that of target IMAGE01011. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0, 0.175; 1011 LOW-SKY; SEQ 1-2 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0, 0.175; 1011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ 3 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 10 S POS TARG 0.175, 0; SEQ 1011 3-5 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 4 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1210 S POS TARG 0.175, 0; 1011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ 5 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1210 S POS TARG 0.175, 0; 1011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ JUL02IMAGE01011 1 ACS/WFC ACCUM WFC F606W none none none none 1 N/A JUL02IMAGE01011 2 ACS/WFC ACCUM WFC F606W none none none none 1 N/A JUL02IMAGE01011 3 ACS/WFC ACCUM WFC F606W none none none none 2 N/A JUL02IMAGE01011 4 ACS/WFC ACCUM WFC F606W none none none none 2 N/A JUL02IMAGE01011 5 ACS/WFC ACCUM WFC F606W none none none none 2 N/A 10146( 4) - 03/30/05 11:44 - [ 6] Visit: 03 Visit Priority: Visit Requirements: ORIENT 91.7839D TO 91.7839 D On Hold Comments: Additional Comments: NOTEs: This visit contains just 4 long exposure in filter F606W. There are two different pointings, each at a different orbit to save time. The long exposure are taken imposing LOW SKY The orientation is that of target IMAGE01011. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0.0125, 0.0125; 1011 LOW-SKY; SEQ 1-2 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0.0125, 0.0125; 1011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ 3 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1259 S POS TARG 0.1875, 0.1875; 1011 LOW-SKY; SEQ 3-4 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 4 JUL02IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1259 S POS TARG 0.1875, 0.1875; 1011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ JUL02IMAGE01011 1 ACS/WFC ACCUM WFC F606W none none none none 1 N/A JUL02IMAGE01011 2 ACS/WFC ACCUM WFC F606W none none none none 1 N/A JUL02IMAGE01011 3 ACS/WFC ACCUM WFC F606W none none none none 2 N/A JUL02IMAGE01011 4 ACS/WFC ACCUM WFC F606W none none none none 2 N/A 10146( 4) - 03/30/05 11:44 - [ 7] Visit: 04 Visit Priority: Visit Requirements: ORIENT 83.575D TO 83.575 D On Hold Comments: Additional Comments: NOTEs: This visit contains 1 short exposure in F775W and 4 long exposure in filter F606W. There are two different pointings, each at a different orbit to save time. The long exposure are taken imposing LOW SKY The orientation is that of target IMAGE03011. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 JUN03IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0, 0; LOW-SKY; 3011 SEQ 1-2 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 JUN03IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0, 0; LOW-SKY 3011 ------------------------------------------------------------------------------------------------------------------------------------ 3 JUN03IMAGE0 ACS/WFC ACCUM WFC F775W GAIN=2,CR-SPLIT=NO 1 0.5 S POS TARG 0.175, 0.175; 3011 SEQ 3-5 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 4 JUN03IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1175 S POS TARG 0.175, 0.175; 3011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ 5 JUN03IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1175 S POS TARG 0.175, 0.175; 3011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ JUN03IMAGE03011 1 ACS/WFC ACCUM WFC F606W none none none none 1 N/A JUN03IMAGE03011 2 ACS/WFC ACCUM WFC F606W none none none none 1 N/A JUN03IMAGE03011 3 ACS/WFC ACCUM WFC F775W none none none none 2 N/A JUN03IMAGE03011 4 ACS/WFC ACCUM WFC F606W none none none none 2 N/A JUN03IMAGE03011 5 ACS/WFC ACCUM WFC F606W none none none none 2 N/A 10146( 4) - 03/30/05 11:44 - [ 8] Visit: 05 Visit Priority: Visit Requirements: ORIENT 83.575D TO 83.575 D On Hold Comments: Additional Comments: NOTEs: This visit contains 1 mid exposure in F775W and 4 long exposure in filter F606W. There are two different pointings, each at a different orbit to save time. The long exposure are taken imposing LOW SKY The orientation is that of target IMAGE03011. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 JUN03IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0, 0.175; 3011 LOW-SKY; SEQ 1-2 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 JUN03IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1218 S POS TARG 0, 0.175; 3011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ 3 JUN03IMAGE0 ACS/WFC ACCUM WFC F775W GAIN=2,CR-SPLIT=NO 1 10 S POS TARG 0.175, 0; SEQ 3011 3-5 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 4 JUN03IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1170 S POS TARG 0.175, 0; 3011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ 5 JUN03IMAGE0 ACS/WFC ACCUM WFC F606W GAIN=2,CR-SPLIT=NO 1 1170 S POS TARG 0.175, 0; 3011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ JUN03IMAGE03011 1 ACS/WFC ACCUM WFC F606W none none none none 1 N/A JUN03IMAGE03011 2 ACS/WFC ACCUM WFC F606W none none none none 1 N/A JUN03IMAGE03011 3 ACS/WFC ACCUM WFC F775W none none none none 2 N/A JUN03IMAGE03011 4 ACS/WFC ACCUM WFC F606W none none none none 2 N/A JUN03IMAGE03011 5 ACS/WFC ACCUM WFC F606W none none none none 2 N/A 10146( 4) - 03/30/05 11:44 - [ 9] Visit: 06 Visit Priority: Visit Requirements: ORIENT 91.7839D TO 91.7839 D On Hold Comments: Additional Comments: NOTEs: This visit contains: 4 long exposures in filter F775W, and one at the beginning of the second orbit during the not low sky part of it. There are two different pointings, each at a different orbit to save time. The long exposures are taken imposing LOW SKY The orientation is that of target IMAGE01011. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 JUL02IMAGE0 ACS/WFC ACCUM WFC F775W GAIN=2,CR-SPLIT=NO 1 1208 S POS TARG 0, 0; LOW-SKY; 1011 SEQ 1-2 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 2 JUL02IMAGE0 ACS/WFC ACCUM WFC F775W GAIN=2,CR-SPLIT=NO 1 1208 S POS TARG 0.27335, 1011 0.02189; LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ 3 JUL02IMAGE0 ACS/WFC ACCUM WFC F775W GAIN=2,CR-SPLIT=NO 1 10 S POS TARG 0, 0.275; SEQ 1011 3-5 NON-INT ------------------------------------------------------------------------------------------------------------------------------------ 4 JUL02IMAGE0 ACS/WFC ACCUM WFC F775W GAIN=2,CR-SPLIT=NO 1 1200 S POS TARG 0, 0.275; 1011 LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ 5 JUL02IMAGE0 ACS/WFC ACCUM WFC F775W GAIN=2,CR-SPLIT=NO 1 1200 S POS TARG 0.27355, 1011 0.29689; LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ JUL02IMAGE01011 1 ACS/WFC ACCUM WFC F775W none none none none 1 N/A JUL02IMAGE01011 2 ACS/WFC ACCUM WFC F775W none none none none 1 N/A JUL02IMAGE01011 3 ACS/WFC ACCUM WFC F775W none none none none 2 N/A JUL02IMAGE01011 4 ACS/WFC ACCUM WFC F775W none none none none 2 N/A JUL02IMAGE01011 5 ACS/WFC ACCUM WFC F775W none none none none 2 N/A 10146( 4) - 03/30/05 11:44 - [ 10] Summary Form for Proposal 10146 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters GAIN=2 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 91.7839D TO 91.7839 D POS TARG 0, 0; LOW-SKY; SEQ 1-2 NON-INT POS TARG 0, 0; LOW-SKY POS TARG 0.175, 0.175; SEQ 3-5 NON-INT POS TARG 0.175, 0.175; LOW-SKY POS TARG 0, 0.175; LOW-SKY; SEQ 1-2 NON-INT POS TARG 0, 0.175; LOW-SKY POS TARG 0.175, 0; SEQ 3-5 NON-INT POS TARG 0.175, 0; LOW-SKY POS TARG 0.0125, 0.0125; LOW-SKY; SEQ 1-2 NON-INT POS TARG 0.0125, 0.0125; LOW-SKY POS TARG 0.1875, 0.1875; LOW-SKY; SEQ 3-4 NON-INT POS TARG 0.1875, 0.1875; LOW-SKY ORIENT 83.575D TO 83.575 D POS TARG 0.27335, 0.02189; LOW-SKY POS TARG 0, 0.275; SEQ 3-5 NON-INT POS TARG 0, 0.275; LOW-SKY POS TARG 0.27355, 0.29689; LOW-SKY ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F606W F775W ------------------------------------------------------------------------------------------------------------------------------------ Target Names JUL02IMAGE01011 JUN03IMAGE03011 ------------------------------------------------------------------------------------------------------------------------------------