11352( 4) - 09/21/07 09:00 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11352 Version: 4 Check-in Time: 21-Sep-2007 12:59:46 STScI Edit Number: 0 Title Mass and distance of the sub-Saturn microlensing planet OGLE-2007-BLG-349Lb ------------------------------------------------------------------------------------ Type Cycle Parallel Pointing Tolerance GO/DD 16 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Andrew Gould The Ohio State University Research Foundation CoI: Dr. Andrzej Udalski Warsaw University N CoI: Mr. Subo Dong The Ohio State University Research N Foundation CoI: Dr. David P. Bennett University of Notre Dame N CoI: Dr. Bernard S. Gaudi The Ohio State University Research N Foundation CoI: Dr. Philip Yock The University of Auckland N CoI: Dr. Rachel Street Las Cumbres Observatory N ------------------------------------------------------------------------------------ Abstract OGLE-2007-BLG-349Lb is the seventh planet discovered using gravitational microlensing, with planet/star mass ratio 2.8e-4. These microlensing planets lie in the cold, outer reaches of their solar systems and are difficult to detect by other techniques because of their long periods. However, microlensing detections by themselves generally give only the planet/star mass ratio, not the absolute planet mass. HST observations have yielded host star masses and distances for two previous microlensing planets. Here, we propose to apply a proven technique to measure the mass and distance of the newest microlensing planet, which was discovered only two weeks ago. We will use WFPC2 observations to unambiguously determine whether the blended light seen during the event is due to the host star (rather than a random interloper) and a combination of WFPC2 and NICMOS observations to obtain photometric estimates of the mass and distance. Two epochs of observations are required, one at high magnification (in the very near future) and the other at baseline (but not too late -- to avoid having the lens move substantially away from the source). ------------------------------------------------------------------------------------ 11352( 4) - 09/21/07 09:00 - [ 2] Observations Description ------------------------ We will use WFPC2 to image the field in I (F814W) at the first epoch and both V (F555W) and I (F814W) at the second epoch, with the object placed in the PC chip. At the two epochs, the source will be I_{Oct10} = 18.8 and (V, I)_{Jun1} = (21.8, 19.9). Using the exposure time calculator, we find that a 5.3 min set of exposures (maximum for the visibility) yields S/N=143, which given the expected magnification lever arm (A = 3.5), is adequate. For the second epoch, we need 4 dithers to measure the PSF elongation in I, and longer exposures for photometry in both bands because the source is fainter. Hence we require two orbits, with (4 ? 5.3) min in I and (4 ? 5.3) min in V . We will use NICMOS/NIC2 to image the field in H (F160W). The source will be H_{Oct10} = 16.6 and H_{Jun1} = 17.8. The 6.1 minutes total exposure (given the visibility) during the first epoch will yield S/N=372, which is more than adequate. A full orbit during the second epoch will yield a S/N that is slightly bigger (S/N = 381). Total request is 5 orbits: one WFPC F814W during 9/Oct - 11/Oct, 2007, one NICMOS/NIC2 F160W during 7/Oct - 13/Oct, plus two WFPC (one F814W + one F555W) between 4/May and 4/June, 2008 and one NICMOS/NIC2 F160W between 13/May and 4/June, 2008. Real Time Justification ----------------------- The microlensing planet was only discovered on 4 Sept 2007. The principal scientific goal of this proposal is the unambiguous identification of the blended light in the microlensing event as the lens (i.e., the planet's host star) in order to determine its mass and distance (and so the mass and physical projected separation of the planet). Identification of the blended light as the lens requires an observation after about 9 months, when the event has returned to baseline but the lens has not yet moved too far, in order to measure the "PSF distortion" of the blend+source. Measurement of the blend color and magnitude requires two measurements, one near baseline and another when the event is substantially magnified. The event will only remain substantially magnified for about a month. Hence both sets of observations require DDT. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 11352( 4) - 09/21/07 09:00 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 OGLE-2007- STAR, EXTRA-SOLAR RA=18H05M24.7400S +/- 0.5", J2000 V = 20.0+/-0.2 BLG-349 PLANET, G V-IV, DEC=-26D25'15.60" +/- 0.5" Spectral Type: G3V GRAVITATIONAL LENS E(B-V) =1 1st Epoch: I = 18.8 +/- 0.1 H = 16.6+/-0.2 F(1600) = 2.7 +/- 0.5 E-17 2nd Epoch: V = 21.8 +/- 0.5 I = 19.9 +/- 0.2 H = 17.8 +/- 0.3 Reference Frame: ICRS Comments: F(1600) = 9 +/- 3 E-18 11352( 4) - 09/21/07 09:00 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type WFPC2-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.559017 Line_Spacing 0.559017 Coordinate_Frame POS-TARG Pattern_Orient 26.56505 Angle_Between_Sides 143.130102 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 5 Primary_Pattern Secondary_Pattern Pattern_Type BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.49322 Line_Spacing 0.4899 Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides 90.0 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 11352( 4) - 09/21/07 09:00 - [ 5] Visit: 01 Visit Priority: Visit Requirements: BETWEEN 08-OCT-2007:12:00:00 AND 13-OCT-2007:12:00:00 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-2007-B WFPC2 IMAGE PC1 F814W CR-SPLIT=0.5 1 320 S LG-349 ------------------------------------------------------------------------------------------------------------------------------------ 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-2007-BLG-349 1 WFPC2 IMAGE PC1 F814W none none none 1 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F814W none none none 2 1 N/A 11352( 4) - 09/21/07 09:00 - [ 6] Visit: 02 Visit Priority: Visit Requirements: ORIENT 89.0D TO 91.0 D; BETWEEN 08-OCT-2007:12:00:00 AND 13-OCT- 2007:12:00:00 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-2007-B NIC2 MULTIAC NIC2-FIX F160W NSAMP=25,SAMP-SEQ=SPARS4 1 DEF PATTERN 5 1 LG-349 CUM ------------------------------------------------------------------------------------------------------------------------------------ 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-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 1 none none none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 2 none none none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 3 none none none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 4 none none none 1 N/A CUM 11352( 4) - 09/21/07 09:00 - [ 7] Visit: 03 Visit Priority: Visit Requirements: BETWEEN 04-MAY-2008:12:00:00 AND 04-JUN-2008:12:00:00 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-2007-B WFPC2 IMAGE PC1 F814W CR-SPLIT=0.5 1 320 S PATTERN 3 1 LG-349 ------------------------------------------------------------------------------------------------------------------------------------ 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-2007-BLG-349 1 WFPC2 IMAGE PC1 F814W 1 none none 1 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F814W 1 none none 2 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F814W 2 none none 1 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F814W 2 none none 2 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F814W 3 none none 1 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F814W 3 none none 2 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F814W 4 none none 1 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F814W 4 none none 2 1 N/A 11352( 4) - 09/21/07 09:00 - [ 8] Visit: 04 Visit Priority: Visit Requirements: BETWEEN 04-MAY-2008:12:00:00 AND 04-JUN-2008:00:00:00 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-2007-B WFPC2 IMAGE PC1 F555W CR-SPLIT=0.5 1 320 S PATTERN 3 1 LG-349 ------------------------------------------------------------------------------------------------------------------------------------ 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-2007-BLG-349 1 WFPC2 IMAGE PC1 F555W 1 none none 1 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F555W 1 none none 2 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F555W 2 none none 1 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F555W 2 none none 2 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F555W 3 none none 1 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F555W 3 none none 2 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F555W 4 none none 1 1 N/A OGLE-2007-BLG-349 1 WFPC2 IMAGE PC1 F555W 4 none none 2 1 N/A 11352( 4) - 09/21/07 09:00 - [ 9] Visit: 05 Visit Priority: Visit Requirements: ORIENT 269.0D TO 271.0 D; BETWEEN 13-MAY-2008:00:00:00 AND 04-JUN- 2008:00:00:00 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-2007-B NIC2 MULTIAC NIC2-FIX F160W NSAMP=23,SAMP-SEQ=SPARS4 7 DEF PATTERN 5 1 LG-349 CUM ------------------------------------------------------------------------------------------------------------------------------------ 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-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 1 none 1 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 1 none 2 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 1 none 3 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 1 none 4 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 1 none 5 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 1 none 6 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 1 none 7 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 2 none 1 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 2 none 2 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 2 none 3 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 2 none 4 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 2 none 5 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 2 none 6 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 2 none 7 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 3 none 1 none 1 N/A CUM 11352( 4) - 09/21/07 09:00 - [ 10] 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-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 3 none 2 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 3 none 3 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 3 none 4 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 3 none 5 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 3 none 6 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 3 none 7 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 4 none 1 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 4 none 2 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 4 none 3 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 4 none 4 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 4 none 5 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 4 none 6 none 1 N/A CUM OGLE-2007-BLG-349 1 NIC2 MULTIAC NIC2-FIX F160W 4 none 7 none 1 N/A CUM 11352( 4) - 09/21/07 09:00 - [ 11] Summary Form for Proposal 11352 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1 NIC2-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 NIC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=0.5 NSAMP=25 SAMP-SEQ=SPARS4 NSAMP=23 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 08-OCT-2007 12 00 00 AND 13-OCT-2007 12 00 00; ORIENT 89.0D TO 91.0 D; BETWEEN 08-OCT-2007 12 00 00 AND 13-OCT-2007 12 00 00; PATTERN 5 1; BETWEEN 04-MAY-2008 12 00 00 AND 04-JUN-2008 12 00 00; PATTERN 3 1; BETWEEN 04-MAY-2008 12 00 00 AND 04-JUN-2008 00 00 00; ORIENT 269.0D TO 271.0 D; BETWEEN 13-MAY-2008 00 00 00 AND 04-JUN-2008 00 00 00; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W F160W F555W ------------------------------------------------------------------------------------------------------------------------------------ Target Names OGLE-2007-BLG-349 ------------------------------------------------------------------------------------------------------------------------------------