10426( 2) - 10/22/04 08:51 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 10426 Version: 2 Check-in Date: 22-Oct-2004 12:50:03 1.Proposal Title: High resolution follow-up observations of the microlensing event OGLE 2003-BLG- 235/MOA 2003-BLG-53 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle 4. Parallel Pointing Tolerance GO 13 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Ian Bond Massey University CoI: Dr. David Bennett University of Notre Dame N CoI: Dr. Michal Jaroszynski Warsaw University N CoI: Prof. Bohdan Paczynski Princeton University N CoI: Dr. Nicholas Rattenbury University of Manchester N CoI: Dr. Andrzej Udalski Warsaw University N CoI: Prof. Philip Yock The University of Auckland N ------------------------------------------------------------------------------------ 6. Abstract We propose high resolution imaging observations using HST/ACS to confirm that the lens in the microlensing event OGLE 2003-BLG-235/MOA 2003-BLG-53 is a planetary system. Modelling of ground based photometry of this event yields an extreme mass fraction of 0.004 (ApJ 606, L155). We aim to use high resolution imaging to isolate the flux of the lens star from the contributions of neighbouring "blended" stars within 1-2 arcsecs. This will allow us to identify the nature of the lens star and hence determine the mass of the stellar and planetary components. The lens is most likely a main sequence star, but other possibilities cannot be ruled out. High resolution imaging observations are crucial in identifying the nature of the lens. ------------------------------------------------------------------------------------ 10426( 2) - 10/22/04 08:51 - [ 2] Observations Description ------------------------ We have proposed high resolution imaging observations using the HST/ACS instrument in the high resolution channel (HRC). We have requested observations over two orbits in a single visit of our target. The requested filters are F435W (Johnson B), F555W (Johnson V), and F814W (broad band I) and we have specified the HST-DITHER-BOX pattern for each filter. We have specified CR- SPLIT=2 for each sub-exposure at each position in the dither pattern. Therefore, one exposure for each filter will comprise 8 sub-exposures. The observation sequence comprises one long exposure in F435W with a total integration time of 1800s on the first orbit. The second orbit comprises one exposure in F555W followed by one exposure in F814W with total integration times of 1200 s and 480 s respectively. Our "target" is the microlensing event OGLE 2003-BLG-235/MOA 2003-BLG-53. However, we also require measurements of other stars within the field of view of the ACS/HRC. The brightest stars have V~17 which, according to the Exposure Time Calculator, would not saturate in individual sub-exposures in each filter exposure. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10426( 2) - 10/22/04 08:51 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 OGLE-03-BLG- STAR, G V-IV RA=18H05M16.3600S +/- 0.1", J2000 V = 20.7+/-0.1 235.MOA-03- DEC=-28D53'42.10" +/- 0.1" I = 19.3 +/- 0.1 BLG-53 Coordinate Source: Other_Source: Own measurement 10426( 2) - 10/22/04 08:51 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-HRC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.15 Line_Spacing 0.098 Coordinate_Frame POS-TARG Pattern_Orient 19.89 Angle_Between_Sides 63.5 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 10426( 2) - 10/22/04 08:51 - [ 5] Visit: 01 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 OGLE-03-BLG ACS/HRC ACCUM HRC F435W 1 570 S PATTERN 1 1 -235.MOA-03 -BLG-53 ------------------------------------------------------------------------------------------------------------------------------------ 2 OGLE-03-BLG ACS/HRC ACCUM HRC F555W 1 330 S PATTERN 1 2 -235.MOA-03 -BLG-53 ------------------------------------------------------------------------------------------------------------------------------------ 3 OGLE-03-BLG ACS/HRC ACCUM HRC F814W 1 120 S PATTERN 1 3 -235.MOA-03 -BLG-53 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ OGLE-03-BLG-235.MO 1 ACS/HRC ACCUM HRC F435W 1 none none 1 1 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 1 ACS/HRC ACCUM HRC F435W 1 none none 2 1 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 1 ACS/HRC ACCUM HRC F435W 2 none none 1 1 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 1 ACS/HRC ACCUM HRC F435W 2 none none 2 1 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 1 ACS/HRC ACCUM HRC F435W 3 none none 1 1 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 1 ACS/HRC ACCUM HRC F435W 3 none none 2 1 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 1 ACS/HRC ACCUM HRC F435W 4 none none 1 1 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 1 ACS/HRC ACCUM HRC F435W 4 none none 2 1 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 2 ACS/HRC ACCUM HRC F555W 1 none none 1 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 2 ACS/HRC ACCUM HRC F555W 1 none none 2 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 2 ACS/HRC ACCUM HRC F555W 2 none none 1 2 N/A A-03-BLG-53 10426( 2) - 10/22/04 08:51 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ OGLE-03-BLG-235.MO 2 ACS/HRC ACCUM HRC F555W 2 none none 2 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 2 ACS/HRC ACCUM HRC F555W 3 none none 1 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 2 ACS/HRC ACCUM HRC F555W 3 none none 2 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 2 ACS/HRC ACCUM HRC F555W 4 none none 1 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 2 ACS/HRC ACCUM HRC F555W 4 none none 2 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 3 ACS/HRC ACCUM HRC F814W 1 none none 1 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 3 ACS/HRC ACCUM HRC F814W 1 none none 2 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 3 ACS/HRC ACCUM HRC F814W 2 none none 1 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 3 ACS/HRC ACCUM HRC F814W 2 none none 2 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 3 ACS/HRC ACCUM HRC F814W 3 none none 1 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 3 ACS/HRC ACCUM HRC F814W 3 none none 2 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 3 ACS/HRC ACCUM HRC F814W 4 none none 1 2 N/A A-03-BLG-53 OGLE-03-BLG-235.MO 3 ACS/HRC ACCUM HRC F814W 4 none none 2 2 N/A A-03-BLG-53 10426( 2) - 10/22/04 08:51 - [ 7] Summary Form for Proposal 10426 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures HRC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/HRC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 1 PATTERN 1 2 PATTERN 1 3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F435W F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names OGLE-03-BLG-235.MOA-03-BLG-53 ------------------------------------------------------------------------------------------------------------------------------------