9342( 3) - 02/12/02 10:37 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9342 Version: 3 Check-in Date: 12-Feb-2002 10:37:12 1.Proposal Title: Confirmation of Black Hole, Planetary, and Binary Microlensing Events ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: David Bennett University of Notre Dame CoI: Prof. Sun Hong Rhie University of Notre Dame N CoI: Dr. Kem Cook Lawrence Livermore National Laboratory N CoI: Prof. Dante Minniti P. Universidad Catolica N ------------------------------------------------------------------------------------ 5. Abstract We propose WFPC2 images of five MACHO Project microlensing events in order to confirm our microlensing models which indicate that these events were caused by black holes and stars with extra-solar planets. Our microlensing parallax fits for MACHO-96-BLG-5 and MACHO-97-BLG-6 indicate that the lenses are likely to be black holes of ~ 40M(sun) and ~ 8M(sun), respectively, and we can test these models by comparing the amount of stellar blended predicted by the model with the blended determined from the WFPC2 images. For the large mass black hole candidate MACHO-96- BLG-5, we propose a time series of observations to follow the declining magnification of ~ 0.4 mag over the next several years as predicted by the microlensing model. For the two extra-solar planet candidates reported by the Microlensing Planet Search (MPS) Collaboration, MACHO-97-BLG-41 and MACHO-98-BLG-35, we propose to test the planetary microlensing models by determining the amount of blending between each source star and its neighbors. Our observations of MACHO-97- BLG-41, will serve as a first epoch for the possible observation of this triple lens system moving away from the source star. Finally, we propose to image binary lensing event MACHO-98-SMC-1 to test our ability to determine the location of the lens systems for such events. ------------------------------------------------------------------------------------ 9342( 3) - 02/12/02 10:37 - [ 2] Observations Description ------------------------ We propose to obtain multi-color images of two black hole microlensing events and two planetary microlensing events toward the Galactic bulge as well as one binary lens source star in the Small Magellanic Cloud. The microlensed source will always be placed on the PC and we will use box dither patterns for maximum spatial resolution. The first epoch of photometry for our massive black hole event, MACHO-96-BLG-5, was obtained in June under DD proposal 8490 with the understanding that further observations would be undertaken as a part of a this GO proposal. Our request includes two visits in each of cycles 9, 10, and 11 to obtain a time series of photometry in the F555W and F814W filter bands. These filters are selected so that the microlensing prediction of achromatic brightening can be verified without requiring more than one orbit per visit. With total exposure times of 1320 sec in F555W and 600 sec in F814W, we expect a signal-to-noise ratio ranging from 110 to 85 as the brightness of the target decreases. This will allow a precise comparison to the predicted microlensing light curve. In the first visit, we request a total of 4 orbits to obtain images in the F439W, F555W, F675W, and F814W passbands. 2 of these orbits will be used for the F439W exposures yielding a signal-to-noise ratio of about 50. The total exposures in the F555W, F675W, and F814W passbands will be about 1700, 1000, and 700 sec respectively yielding a signal-to-noise ratio of better than 120 in each filter. This will yield BVRI colors accurate to 2.5\ accurate to 1.5\ star and will allow us to determine the reddening to the source. This accurate photometry will also allow us to test the blending prediction of our microlensing fit which provides a stringent test of our black hole interpretation. Additionally, this photometry will allow us to estimate the chances that the source star is in the Sagittarius dwarf which would reduce the black hole mass estimate by about 30\ in order to tie our photometry to ground based observations. For our second black hole candidate, MACHO-98-BLG-6, the future change in magnification is small, and the blending is predicted to be much less severe, so WFPC2 observations of the time variation of this event are not needed. We request 2 orbits to obtain images in the F439W, F555W, F675W, and F814W passbands, and the total exposure times will be approximately 3500, 400, 400, and 160 seconds, respectively. This will yield a signal-to-noise ratio of better than 80 in the F439W filter band and better than 140 in the other filter bands resulting in BVRI colors accurate to better than 2\ the microlensing fit blending prediction, and also confirm that the source is indeed a normal star. One of our objectives of our WFPC2 observations of our binary star plus planet system, MACHO-97-BLG-41, is to possibly detect the proper motion of the brightest star in the lens system as it moves away from the source star. This requires that we obtain high signal-to-noise images in the passbands that will be useful for the attempted proper motion measurements: F555W, F675W, and F814W. Multicolor proper motion measurements are required to confirm a faint, moving object has colors consistent with those expected for the brightest lens star. We propose total exposure times of 2000, 800, and 800 sec respectively in the F555W, F675W, and F814W passbands respectively. These will yield signal-to-noise ratios of about 400 in all three passbands, and will be sufficient to reduce the Poisson noise to less than 1\ This may allow the detection of the primary lens star in a second epoch image in 5-7 years. We also propose an additional orbit to obtain total exposure of 2700 sec of MACHO- 97-BLG-41 in the F439W passband in order to obtain BVRI colors for the source star. The predicted signal-to-noise ratio for the F439W observations is about 88, so we should obtain colors to better than 2\ our estimate for the source star angular size which is critical for the determination of the masses of the stars and the planet in the lens system. The photometry of MACHO-97-BLG-41 will also provide a test of the blending prediction from our binary lens plus planet model. We have requested a single orbit to obtain images of our low mass planetary lens candidate, MACHO-98-BLG-35. This event has no caustic crossings, so the angular size of the source star is not critical for the interpretation of the event, so our primary goal is to test the blending prediction of our planetary fit. We request total exposures of 600, 400, and 300 seconds respectively in the F555W, F675W, and F814W passbands as these are the passbands that most closely correspond to the filters used in the ground based observations. These will yield a signal-to-noise ratio of better than 140 in each passband. We also request a series of 40 sec exposures in each passband to tie the photometry scales to those of the ground based images. Our final target is SMC binary lensing event MACHO-98-SMC-1 where our main goal is to test the blending predictions of the different light curve fits. Exposures of 1200 and 500 sec in the F814W and F555W passbands respectively will yield a signal-to- noise ratio of better than 60 which is sufficient to test the blending predictions. Additional 40 sec exposures will also be taken in order compare to ground based photometry. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 9342( 3) - 02/12/02 10:37 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 96-BLG-5 STAR, BULGE, G V-IV RA=18H 5M 2.5S +/- 2", DEC=-27D J2000 V = 21.5+/-0.2 42' 17" +/- 2" V-R = 0.8+/-0.1 Coordinate Source: IMAGE_TIED_TO_GSC_FRAME 9342( 3) - 02/12/02 10:37 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFPC2-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.559017 Coordinate_Frame POS-TARG Pattern_Orient 26.565051 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 9342( 3) - 02/12/02 10:37 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 94.605320D TO 94.605320D BETWEEN 01-Oct-2002 AND 01-Jan-2003 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 96-BLG-5 WFPC2 IMAGE PC1 F555W CLOCKS=YES 2 400 S ------------------------------------------------------------------------------------------------------------------------------------ 50 96-BLG-5 WFPC2 IMAGE PC1 F814W 1 160 S PATTERN 1 50 ------------------------------------------------------------------------------------------------------------------------------------ 9342( 3) - 02/12/02 10:37 - [ 6] Visit: 02 Visit Priority: Visit Requirements: ORIENT 299.605320D TO 299.605320D AFTER 31-Dec-2002 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 96-BLG-5 WFPC2 IMAGE PC1 F555W CLOCKS=YES 2 400 S ------------------------------------------------------------------------------------------------------------------------------------ 20 96-BLG-5 WFPC2 IMAGE PC1 F814W 1 160 S PATTERN 1 20 ------------------------------------------------------------------------------------------------------------------------------------ 9342( 3) - 02/12/02 10:37 - [ 7] Summary Form for Proposal 9342 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CLOCKS=YES ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 94.605320D TO 94.605320D BETWEEN 01-Oct-2002 AND 01-Jan-2003 PATTERN 1 50 ORIENT 299.605320D TO 299.605320D AFTER 31-Dec-2002 PATTERN 1 20 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names 96-BLG-5 ------------------------------------------------------------------------------------------------------------------------------------