13809( 2) - 23-Jul-2014 22:37:05 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13809 Version: 2 Check-in Time: 23-Jul-2014 22:37:05 STScI Edit Number: 0 Title The IMF and Internal Kinematics of the Massive Young Star Cluster, Westerlund 1 ------------------------------------------------------------------------------------ Type Cycle GO 22 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Jessica R. Lu University of Hawaii Y CoI: Dr. Nate McCrady University of Montana - Missoula N CoI: Dr. Mark R. Morris University of California - Los Angeles N CoI: Dr. Andrea M. Ghez University of California - Los Angeles N CoI: Dr. William I. Clarkson University of Michigan N CoI: Dr. Jay Anderson Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract The most massive young star cluster known in the Milky Way, Westerlund 1, represents a far more extreme environment for star formation than nearby, well-studied, and lower-mass star forming regions such as Taurus and Orion. We propose to construct a complete photometric and kinematic census of Westerlund 1 in order to identify cluster members down to 0.1 solar masses, precisely determine the initial mass function (IMF), and measure the internal kinematic structure of the cluster. With these measurements, we will test whether the IMF is universal, as may be the case for nearby lower-mass star forming regions, or favors high-mass star formation, as has been suggested theoretically and from some observational results. We will observe Wd 1 with WFC3-IR, which is the only instrument capable of delivering high spatial resolution, a well-characterized and stable PSF, and a wide field of view at infrared wavelengths. We exploit WFC3's capabilities to cover the full extent of the cluster with photometry, to correct for variable extinction and derive stellar masses, and with proper motions, to distinguish between cluster members and contaminating field stars. Our proposed observations of Westerlund 1 will help determine whether the star formation process, and the emergent stellar mass distribution, varies with initial cloud conditions. ------------------------------------------------------------------------------------ Observations Description ------------------------ Our program to measure the IMF and internal kinematics of the massive young cluster, Westerlund 1, requires both astrometric and near-infrared photometric observations. Archival HST data sets of Wd 1 include multi-band WFC3-IR imaging of the full extent of the cluster, which we will use as our first epoch of observation when establishing membership probabilities down to the lowest stellar masses. New observations in cycle 20 and cycle 22 would be obtained with WFC3 in the near infrared to provide additional astrometric epochs. A 2x2 (4'x4') mosaic is needed to cover the full cluster extent. We will obtain 2 additional observations using WFC3-IR in cycle 20 and cycle 22 specifically optimized for astrometry. Our target goal is to identify cluster members down to the limits of the existing WFC3-IR data at 0.1 solar masses, which corresponds to H=20.5. In order to effectively select the field stars, we 13809( 2) - 23-Jul-2014 22:37:05 - [ 2] require a 1 sigma proper motion precision of <0.3 mas/yr. We will use existing data from 2010 and new observations in cycles 20 (2013) and 22 (2015) with a total time baseline of 5 years to achieve our desired proper motion errors. We will measure the astrometry with WFC3's longest-wavelength filter (F160W) to minimize the impact of extinction. Therefore, we need a total SNR=160 on the stars of interest to achieve an astrometric precision of 1 mas and a final velocity precision of 0.3 mas/yr. Additionally, to minimize the impact of geometric distortions, we request that the astrometric observations have the SAME ORIENT with small POSTARG offsets as the 2010 observations. Our observations require a high dynamic range as we are interested in both the higher mass, brighter stars (typically H=0) and the lower mass, fainter stars (typically H=20.5) in the cluster. As a result we must limit our integration time per exposure so as to avoid saturating too many stars, such that the resulting persistence images would not impact the astrometric and photometric measurements. We also adopt a minimum integration time that still allows us to dump the WFC3 buffer in parallel (249 s for a STEP50 readout pattern with 10 MULTIACCUM reads). Integration times for observations of Wd 1 in the F160W filter were calculated with the WFC3 exposure time calculator to achieve SNR=160 for an H=20.5 star with a late M dwarf spectral type and an E(B-V) = 3.5. For each position in our proposed 2x2 mosaic of Wd 1, we require 14 exposures for a total of 3486 s of integration time. We also require additional short exposures in sub-arrayed mode to capture the most massive stars that were saturated in the longer exposures. This amounts to 7 orbits to complete the entire mosaic in cycle 20. The observations will be repeated in cycle 22 with an additional 7 orbits. --------- Additional Comments ---------- The archival observations have the PID 11708 and the cycle 20 observations have the PID 13044. We request that our new observations have the same orientation and detector position as the F160W images from the archived data set. The relevant data set numbers are ib5w02, ib5w03, ib5w04, and ib5w05. ------------------------------------------------------------------------------------ 13809( 2) - 23-Jul-2014 22:37:05 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 WESTERLUND1 STELLAR CLUSTER, OB RA=16H47M4.0000S +/- 0.1", J2000 V = 12 +/- 1 H=9-20 ASSOCIATION, OPEN DEC=-45D50'42.00" +/- 0.1" CLUSTER, STAR FORMING REGION, YOUNG ASSOCIATION Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 13809( 2) - 23-Jul-2014 22:37:05 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type SPIRAL Pattern_Purpose DITHER Number_Of_Points 14 Point_Spacing 3.26 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 14 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type SPIRAL Pattern_Purpose DITHER Number_Of_Points 13 Point_Spacing 3.26 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 14 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 13809( 2) - 23-Jul-2014 22:37:05 - [ 5] Visit: 01 Visit Requirements: ORIENT 269D TO 270 D 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG 24.2, -21 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG 85.8, -21 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WESTERLUND1 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=STEP50, NSAMP=10 1 DEF POS TARG 55, -55; CUM (3489.248 PATTERN 1 3 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WESTERLUND1 WFC3/IR MULTIAC IR-FIX F160W NSAMP=10, SAMP-SEQ=STEP50 1 DEF POS TARG 55, 55; PATTERN CUM (3240.016 2 4 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG 24.2, 21 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 6 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG 85.8, 21 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WESTERLUND1 1 WFC3/IR MULTIAC IRSUB512 F160W none none none none 1 N/A CUM -FIX WESTERLUND1 2 WFC3/IR MULTIAC IRSUB512 F160W none none none none 1 N/A CUM -FIX WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 5 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 6 none none none 1 N/A CUM 13809( 2) - 23-Jul-2014 22:37:05 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 7 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 8 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 9 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 10 none none none 2 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 11 none none none 2 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 12 none none none 2 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 13 none none none 2 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 14 none none none 2 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 2 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 2 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 2 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 2 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 5 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 6 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 7 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 8 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 9 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 10 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 11 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 12 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 13 none none none 3 N/A CUM WESTERLUND1 5 WFC3/IR MULTIAC IRSUB512 F160W none none none none 3 N/A CUM -FIX WESTERLUND1 6 WFC3/IR MULTIAC IRSUB512 F160W none none none none 3 N/A CUM -FIX 13809( 2) - 23-Jul-2014 22:37:05 - [ 7] Visit: 02 Visit Requirements: SAME ORIENT AS 01; AFTER 01 BY 0 D TO 30 D 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG -85.8, 21 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG -24.1, 21 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WESTERLUND1 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=STEP50, NSAMP=10 1 DEF POS TARG -55, 55; CUM (3489.248 PATTERN 1 3 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WESTERLUND1 WFC3/IR MULTIAC IR-FIX F160W SAMP-SEQ=STEP50, NSAMP=10 1 DEF POS TARG -55, -55; CUM (3240.016 PATTERN 2 4 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG -85.8, -21.0 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 6 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG -24.2, -21 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 7 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG -85.8, 89 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 8 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG -24.2, 89 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 9 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG 24.2, 89 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 10 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG 85.8, 89 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 11 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG -85.8, -89 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 12 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG -24.2, -89 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 13 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG 24.2, -89 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 13809( 2) - 23-Jul-2014 22:37:05 - [ 8] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 14 WESTERLUND1 WFC3/IR MULTIAC IRSUB512- F160W SAMP-SEQ=RAPID, NSAMP=10 1 DEF (8.53 POS TARG 85.8, -89 CUM FIX S) ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ WESTERLUND1 1 WFC3/IR MULTIAC IRSUB512 F160W none none none none 1 N/A CUM -FIX WESTERLUND1 2 WFC3/IR MULTIAC IRSUB512 F160W none none none none 1 N/A CUM -FIX WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 5 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 6 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 7 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 8 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 9 none none none 1 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 10 none none none 2 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 11 none none none 2 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 12 none none none 2 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 13 none none none 2 N/A CUM WESTERLUND1 3 WFC3/IR MULTIAC IR-FIX F160W 14 none none none 2 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 2 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 2 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 2 N/A CUM 13809( 2) - 23-Jul-2014 22:37:05 - [ 9] 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 | ------------------------------------------------------------------------------------------------------------------------------------ WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 2 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 5 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 6 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 7 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 8 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 9 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 10 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 11 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 12 none none none 3 N/A CUM WESTERLUND1 4 WFC3/IR MULTIAC IR-FIX F160W 13 none none none 3 N/A CUM WESTERLUND1 5 WFC3/IR MULTIAC IRSUB512 F160W none none none none 3 N/A CUM -FIX WESTERLUND1 6 WFC3/IR MULTIAC IRSUB512 F160W none none none none 3 N/A CUM -FIX WESTERLUND1 7 WFC3/IR MULTIAC IRSUB512 F160W none none none none 4 N/A CUM -FIX WESTERLUND1 8 WFC3/IR MULTIAC IRSUB512 F160W none none none none 4 N/A CUM -FIX WESTERLUND1 9 WFC3/IR MULTIAC IRSUB512 F160W none none none none 4 N/A CUM -FIX WESTERLUND1 10 WFC3/IR MULTIAC IRSUB512 F160W none none none none 4 N/A CUM -FIX WESTERLUND1 11 WFC3/IR MULTIAC IRSUB512 F160W none none none none 4 N/A CUM -FIX WESTERLUND1 12 WFC3/IR MULTIAC IRSUB512 F160W none none none none 4 N/A CUM -FIX WESTERLUND1 13 WFC3/IR MULTIAC IRSUB512 F160W none none none none 4 N/A CUM -FIX WESTERLUND1 14 WFC3/IR MULTIAC IRSUB512 F160W none none none none 4 N/A CUM -FIX 13809( 2) - 23-Jul-2014 22:37:05 - [ 10] Summary Form for Proposal 13809 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR-FIX, IRSUB512-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR ------------------------------------------------------------------------------------------------------------------------------------ Opmodes MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters NSAMP=10, SAMP-SEQ=RAPID, SAMP-SEQ=STEP50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 01 BY 0 D TO 30 D, ORIENT 269D TO 270 D, PATTERN 1 3, PATTERN 2 4, POS TARG -24.1, 21, POS TARG -24.2, -21, POS TARG -24.2, -89, POS TARG -24.2, 89, POS TARG -55, -55, POS TARG -55, 55, POS TARG -85.8, -21.0, POS TARG -85.8, -89, POS TARG -85.8, 21, POS TARG -85.8, 89, POS TARG 24.2, -21, POS TARG 24.2, -89, POS TARG 24.2, 21, POS TARG 24.2, 89, POS TARG 55, -55, POS TARG 55, 55, POS TARG 85.8, -21, POS TARG 85.8, -89, POS TARG 85.8, 21, POS TARG 85.8, 89, SAME ORIENT AS 01 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F160W ------------------------------------------------------------------------------------------------------------------------------------ Target Names WESTERLUND1 ------------------------------------------------------------------------------------------------------------------------------------