8655( 3) - 05/18/00 11:04 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8655 Version: 3 Check-in Date: 18-May-2000 11:02:48 1.Proposal Title: Geometric Distances of Globular Clusters (GO part) ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 9 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Ivan King University of California - Berkeley CoI: Dr. Jay Anderson University of California, Berkeley N CoI: Dr. Karl Gebhardt UCSC/Lick Observatory N CoI: Dr. Carlton Pryor Rutgers, the State Univ. of New Jersey N ------------------------------------------------------------------------------------ 5. Abstract This is a proposal to establish a globular-cluster distance scale of unprecedented accuracy and reliability, with far- reaching impact on the distance and time scales of cosmology. Our method is to compare internal dispersions of proper motion with ground-based determinations of the dispersion of radial velocities. The prospect is a geometrically based distance scale with an accuracy of better than 2\ ability to make such measurements, and we are progressing with the conversion of them to a distance for the cluster. Our project has two parts: (1) Where possible, we use archival observations for both astrometric epochs (see accompanying AR proposal, which covers 2 clusters). (2) The present proposal covers 5 more clusters for which an archival first epoch exists but for which we lack second-epoch observations. With this proposal, the accompanying AR proposal, and other HST collaborations in which we are involved, we expect to determine accurate distances for 13 clusters, with a large range of metallicities and second-parameter characteristics. (Moreover, we intend to cover additional clusters in future ACS proposals.) ------------------------------------------------------------------------------------ 8655( 3) - 05/18/00 11:04 - [ 2] Observations Description ------------------------ The first-epoch images for each cluster were taken through a variety of filters with a variety of exposure times. All of them can of course be used together for purposes of astrometry. Optimizing for astrometry: The advantage of proposing 2nd-epoch observations is that we now know exactly what to expect in each image in terms of background, saturation, and crowding. We can therefore choose the second-epoch filters and exposures wisely. The only thing we do not know about the fields, in fact, is how much each star has moved. It should be noted that the 2nd-epoch exposures do not need to be deep enough to reach all the stars that were imaged in the 1st epoch. For comparison with the radial velocities, which are for stars at or above the main-sequence turnoff, the most important stars are those that are less than a magnitude below the turnoff. Fainter stars have lower masses, and dynamical relaxation will give them a higher velocity dispersion than the stars for which we have radial velocities. On the other hand, this very tendency toward equipartition is of dynamical interest and makes the fainter stars worth measuring for this additional return, in so far as they can be included. We recognize, however, that the distances are the greatest prize, and we will optimize the exposures for them. We found in our 47-Tuc study that a bluer filter is preferable when observing stars in globulars, since it suppresses the background light from the bright giants. It also has fewer saturated stars in a given exposure time, which lessens the need for short exposures. Observations in F300W are ideal for this; however, they require long exposure times (~350s). Instead, we choose F450W as a nice compromise between low background and reasonable integration time. For most clusters below, these B exposures require less than 100s to match the depth of the 1st epoch. We will dither the 2nd epoch as multiply as possible, so that we can sample the PSF as well as possible. A 1st epoch that is not optimally dithered can be remedied by a well-dithered 2nd epoch. All of the images referred to here are at the cluster centers. Our follow-up observations will have the PC centered on the core and oriented such as to get the maximum WF overlap with previous exposures. Each target will require 2 orbits, into which we fit 12 to 16 exposures of 100s to 200s each. NGC 2808: There are 2 earlier epochs:\ in Dec.\ 1995 there is a 50s exposure with F555W and 2*230s with F439W; these images show a rich population of giant stars. In Mar.\ 1998 we have 4 F336W exposures totaling 6400s, 3* 100s in F555W, and 3*120s in F814W; these images have thousands of RGB and HB stars. In Mar.\ 2001 we will point at the 1998 field, which is the better observed of the 1st-epoch fields; the 1995 field has about a 50\% overlap. NGC 5139: The 1st epoch, in June 1997, has an ideal star density for astrometry, with more than 10, 000 measurable stars; there are 19 exposures of good length, divided between F336W, F675W, and F656N. Because of the large velocity dispersion expected in this cluster, the 4 - year time baseline to June 2001 will give excellent accuracy. NGC 6093: In view of the relatively small proper-motion dispersion expected in this cluster, the archival material seems inadequate when taken alone. Adding new images promises an excellent result. In order to match the depth of the previous images, we use longer exposures here than in the other clusters. NGC 6254: 1st epoch (May 1997) has 3*500s in F336W and 2*30s in F555W. We can measure more than 2000 stars, to at least 1 mag below the turnoff. NGC 6541: 1st epoch (1994) has 2 overlapping fields, each with 7 exposures totaling 586s in F555W and 6 exposures totaling 840s in F814W. Because the 1st-epoch images go deep, here we use F606W, to hold the GO follow-up down to 2 orbits. The analysis: While high-precision astrometry (errors less than 1 mas) is certainly possible with WFPC2, it is by no means trivial. Evidence of this is the fact that very few scientific papers (~10) have been published to date that rely on WFPC2 astrometry. With support from AR-7993 and 7994, we have spent the last year and a half developing techniques for measuring accurate positions on WFPC2 images, and are very close to publishing a paper describing our methods and their rationale. We have discovered that three major sources of systematic error must be properly addressed if we are to obtain good measurements. Each of these errors can introduce systematic biases on the order of ~3 mas, which is considerably larger than the typical displacement in many anticipated surveys. (1) The first of these systematic errors comes from the 34-th row manufacturing defect present in all WFPC2 chips (see Anderson & King 1999). (2) The second systematic error is due to optical distortion. While the standard distortion coefficients correct up to 2 pixels of distortion from chip-edges to the centers, there remain systematic errors on the order of 0.05 pixel. In addition, plate-scale changes due to breathing can introduce additional error in global fits. We find that by doing astrometry differentially, by means of local transformations based on the positions of each star's nearby neighbors (see King et al.\ 1998), we can dramatically reduce these residual distortion errors. (3) Finally, the undersampled nature of WFPC2 imaging can introduce systematic errors of 0.03 pixel in the fitting of star positions. We find that these errors are due to inadequacies in modeling the undersampled PSF, and are correlated with the star's pixel phase (where its center falls with respect to pixel centers). This pixel-phase error can be removed by using an extremely accurate PSF, which we obtain by combining measurements of a large number of stars, each of them seen in many different dither pointings. We treat the spatial variation by constructing an independent PSF in 9 different parts of each chip and interpolating among them to obtain, for each star, the PSF that is appropriate for its position. Typical results are shown in Figure 1. We measure the position of a star image with an error of less than 0.02 pixel in each coordinate, for stars with >= 100 DN in their brightest pixel. With the systematic errors gone, we combine multiple measurements with the full gain of SQRT( N, so that the mean of 16 images gives us an accuracy better than 0.005 pixel (0.2 mas in the PC and 0.4 mas in the WF). In our 47 Tuc data set we have 5000 such stars in the PC and 15, 000 such stars in the WF chips, with r.m.s. displacements, in 2 years, of 0.06 pixel in the PC and 0.03 in the WF. Real Time Justification ----------------------- Orientations and approximate dates will be requested, to match 2nd-epoch to existing 1st-epoch observations. The radial-velocity observations are carried out by Gebhardt and Pryor, who use the Rutgers Fabry--Perot etalons with imaging spectrometers on ground-based telescopes in both hemispheres. These efficient instruments can yield thousands of radial velocities per night when targeted at the central regions of globular clusters. The samples of stars with radial velocities that are currently in hand are: NGC 2808 (our GO): 3700 velocities NGC 5139 (our GO): 8000 velocities NGC 6093 (our GO): 740 reduced NGC 6121 (our cycle 8 GO): 2400 velocities NGC 6397 (our AR): 130 reduced, 1000 more not yet reduced NGC 6205 (van Altena program): 500 velocities NGC 6752 (van Altena program): 500 reduced, 1000 not yet reduced NGC 7078 (van Altena program):1800 reduced, 300 not yet reduced NGC 104 (Meylan Program that we are in): 3500 reduced A replacement for the Rutgers Fabry Perot at CTIO with a larger field of view and designed to exploit the improved seeing will be available in the spring semester of 2001. Using this instrument in the south and the old Rutgers etalons in the north, our goal is to obtain at least 2500 velocities for all 13 of the clusters in this program. This will be challenging for clusters with absolute magnitudes fainter than -8.0, but should be achievable with about 5 nights of observing on 4-m telescopes and 7 nights on 1.5-m telescopes (i.e, to fill out the needed data for all 13 of the clusters). Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8655( 3) - 05/18/00 11:04 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC2808 STELLAR CLUSTER, RA=09H 12M 2.61S +/- 0.01S, DEC= J2000 SURF(V) = 14.4+/-0.5 GLOBULAR CLUSTER -64D 51' 46.77" +/- 0.01" Coordinate Source: OTHER_SOURCE Comments: Since globular clusters usually turn out to be burned out and useless on Sky Survey images, we have adopted the following procedure. For the image of which this is intended to be a repeat, we go to the proposal that created that image, and repeat here the exact RA, DEC, and aperture that were used there. We check the header of the first-epoch image to verify that the RA and DEC given there (corrected by POS TARGs if applicable) are very close to what we are using here. If that check succeeds, we are confident that we have the right position. For ORIENT we of course go 180D from the P.A. of V3 in the 1st epoch. 2 NGC5139 STELLAR CLUSTER, RA=13H 26M 53.39S +/- 0.01S, J2000 SURF(V) = 16.3+/-0.5 GLOBULAR CLUSTER DEC=-47D 28' 50.73" +/- 0.01" Coordinate Source: OTHER_SOURCE 3 NGC6093 STELLAR CLUSTER, RA=16H 17M 2.41S +/- 0.01S, DEC= J2000 SURF(V) = 14.8+/-0.5 GLOBULAR CLUSTER -22D 58' 34.89" +/- 0.01" Coordinate Source: OTHER_SOURCE 4 NGC6254 STELLAR CLUSTER, RA=16H 57M 8.92S +/- 0.01S, DEC= J2000 SURF(V) = 16.8+/-0.5 GLOBULAR CLUSTER -04D 5' 57.98" +/- 0.01" Coordinate Source: OTHER_SOURCE 5 NGC6541 STELLAR CLUSTER, RA=18H 8M 9.18S +/- 0.01S, DEC=- J2000 SURF(V) = 15.0+/-0.5 GLOBULAR CLUSTER 43D 41' 52.63" +/- 0.01" Coordinate Source: OTHER_SOURCE 8655( 3) - 05/18/00 11:04 - [ 4] Visit: 01 Visit Priority: Visit Requirements: ORIENT 47.5D TO 48.5D On Hold Comments: Additional Comments: Orientation must match that of first-epoch exposures. The dither pattern samples every 16th of a pixel in both x and y, both for the WF and for the PC. 2 orbits, 8 exp. in each. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S Comments: First orbit. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.425, 0.025 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.85, 0.05 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 1.275, 0.075 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.00625, 0.4312 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.4312, 0.4562 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 0.8562, 0.4812 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 1.281, 0.4062 ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.0125, 0.9625 Comments: 2nd orbit. ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.4375, 0.9875 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.8625, 0.9125 ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 1.288, 0.9375 ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.01875, 1.294 ------------------------------------------------------------------------------------------------------------------------------------ 14 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 0.4438, 1.219 ------------------------------------------------------------------------------------------------------------------------------------ 15 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 0.8688, 1.244 ------------------------------------------------------------------------------------------------------------------------------------ 16 NGC2808 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 1.294, 1.269 ------------------------------------------------------------------------------------------------------------------------------------ 8655( 3) - 05/18/00 11:04 - [ 5] Visit: 02 Visit Priority: Visit Requirements: ORIENT 81.5D TO 82.5D On Hold Comments: Additional Comments: Orientation must match that of first-epoch exposures. The dither pattern samples every 16th of a pixel in both x and y, both for the WF and for the PC. 2 orbits, 8 exp. in each. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S Comments: First orbit. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.425, 0.025 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.85, 0.05 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 1.275, 0.075 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.00625, 0.4312 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.4312, 0.4562 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.8562, 0.4812 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 1.281, 0.4062 ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.0125, 0.9625 Comments: 2nd orbit. ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.4375, 0.9875 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.8625, 0.9125 ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 1.288, 0.9375 ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.01875, 1.294 ------------------------------------------------------------------------------------------------------------------------------------ 14 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 0.4438, 1.219 ------------------------------------------------------------------------------------------------------------------------------------ 15 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 0.8688, 1.244 ------------------------------------------------------------------------------------------------------------------------------------ 16 NGC5139 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 1.294, 1.269 ------------------------------------------------------------------------------------------------------------------------------------ 8655( 3) - 05/18/00 11:04 - [ 6] Visit: 03 Visit Priority: Visit Requirements: ORIENT 100.5D TO 101.5D On Hold Comments: Additional Comments: Orientation must match that of first-epoch exposures. The dither pattern samples every 12th of a pixel in both x and y, both for the WF and for the PC. 2 orbits, 6 exp. in each. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 160 S Comments: First orbit. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 160 S POS TARG 0.2167, 0.01667 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 160 S POS TARG 0.4333, 0.03333 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 200 S POS TARG 0.65, 0.05 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 200 S POS TARG 0.06667, 0.2667 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 200 S POS TARG 0.2833, 0.2833 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 160 S POS TARG 0.4083, 0.2583 Comments: 2nd orbit. ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 160 S POS TARG 0.625, 0.275 ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 200 S POS TARG 0.04167, 0.5917 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 200 S POS TARG 0.2583, 0.5083 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 200 S POS TARG 0.475, 0.525 ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC6093 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 200 S POS TARG 0.6917, 0.5417 ------------------------------------------------------------------------------------------------------------------------------------ 8655( 3) - 05/18/00 11:04 - [ 7] Visit: 04 Visit Priority: Visit Requirements: ORIENT 241.5D TO 242.5D On Hold Comments: Additional Comments: Orientation must match that of first-epoch exposures. The dither pattern samples every 15th of a pixel in both x and y, both for the WF and for the PC. 2 orbits, 15 exp. total. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S Comments: First orbit. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.42, 0.02 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 0.84, 0.04 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 1.26, 0.06 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 1.68, 0.08 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 0.006667, 0.4333 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 120 S POS TARG 0.4267, 0.4533 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.8467, 0.4733 Comments: 2nd orbit. ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 1.267, 0.4933 ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 1.687, 0.4133 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.01333, 0.7667 ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.4333, 0.7867 ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 0.8533, 0.7067 ------------------------------------------------------------------------------------------------------------------------------------ 14 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 1.273, 0.7267 ------------------------------------------------------------------------------------------------------------------------------------ 15 NGC6254 WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=NO 1 100 S POS TARG 1.693, 0.7467 ------------------------------------------------------------------------------------------------------------------------------------ 8655( 3) - 05/18/00 11:04 - [ 8] Visit: 05 Visit Priority: Visit Requirements: ORIENT 95.8D TO 96.8D On Hold Comments: Additional Comments: Orientation must match that of first-epoch exposures. The dither pattern samples every 16th of a pixel in both x and y, both for the WF and for the PC. 2 orbits, 8 exp. in each. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S Comments: First orbit. ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 0.425, 0.025 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 0.85, 0.05 ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 1.275, 0.075 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 0.00625, 0.4312 ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 0.4312, 0.4562 ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 0.8562, 0.4812 ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 120 S POS TARG 1.281, 0.4062 ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 0.0125, 0.9625 Comments: 2nd orbit. ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 0.4375, 0.9875 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 0.8625, 0.9125 ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 1.288, 0.9375 ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 0.01875, 1.294 ------------------------------------------------------------------------------------------------------------------------------------ 14 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 100 S POS TARG 0.4438, 1.219 ------------------------------------------------------------------------------------------------------------------------------------ 15 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 120 S POS TARG 0.8688, 1.244 ------------------------------------------------------------------------------------------------------------------------------------ 16 NGC6541 WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=NO 1 120 S POS TARG 1.294, 1.269 ------------------------------------------------------------------------------------------------------------------------------------ 8655( 3) - 05/18/00 11:04 - [ 9] Summary Form for Proposal 8655 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 47.5D TO 48.5D POS TARG 0.425, 0.025 POS TARG 0.85, 0.05 POS TARG 1.275, 0.075 POS TARG 0.00625, 0.4312 POS TARG 0.4312, 0.4562 POS TARG 0.8562, 0.4812 POS TARG 1.281, 0.4062 POS TARG 0.0125, 0.9625 POS TARG 0.4375, 0.9875 POS TARG 0.8625, 0.9125 POS TARG 1.288, 0.9375 POS TARG 0.01875, 1.294 POS TARG 0.4438, 1.219 POS TARG 0.8688, 1.244 POS TARG 1.294, 1.269 ORIENT 81.5D TO 82.5D ORIENT 100.5D TO 101.5D POS TARG 0.2167, 0.01667 POS TARG 0.4333, 0.03333 POS TARG 0.65, 0.05 POS TARG 0.06667, 0.2667 POS TARG 0.2833, 0.2833 POS TARG 0.4083, 0.2583 POS TARG 0.625, 0.275 POS TARG 0.04167, 0.5917 POS TARG 0.2583, 0.5083 POS TARG 0.475, 0.525 POS TARG 0.6917, 0.5417 ORIENT 241.5D TO 242.5D POS TARG 0.42, 0.02 POS TARG 0.84, 0.04 POS TARG 1.26, 0.06 POS TARG 1.68, 0.08 POS TARG 0.006667, 0.4333 POS TARG 0.4267, 0.4533 POS TARG 0.8467, 0.4733 POS TARG 1.267, 0.4933 POS TARG 1.687, 0.4133 POS TARG 0.01333, 0.7667 POS TARG 0.4333, 0.7867 POS TARG 0.8533, 0.7067 POS TARG 1.273, 0.7267 POS TARG 1.693, 0.7467 ORIENT 95.8D TO 96.8D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F450W F606W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC2808 NGC5139 NGC6093 NGC6254 NGC6541 ------------------------------------------------------------------------------------------------------------------------------------