6460( 3) - 02/09/96 13:50 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6460 Version: 3 Check-in Date: 09-Feb-1996 13:44:18 1.Proposal Title: Where are the Dozens of Predicted Cataclysmic Variables in Globular Clusters? ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle BINARIES AND STAR FOR GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Michael Shara Space Telescope Science Institute CoI: David Zurek Space Telescope Science Institute N CoI: Louis Bergeron New Mexico State University N ------------------------------------------------------------------------------------ 6. Abstract WFPC2 imaging of globular cluster cores provides us with a unique opportunity to detect erupting cataclysmic variables (CVs) because they should be relatively common in the core. Two body tidal capture theory predicts that all binary systems should be relatively common in globular clusters, up to several orders of magnitude greater in relative number than in the Galactic field. Among the most common binaries should be CVs because of the high presumed abundance of white dwarfs in globular cores. However, only a handful of confirmed CVs have been discovered in globular clusters to date. This paucity brings into question the dynamical theories which predict great numbers of CVs. We propose to image the cores of two globular clusters with WFPC2 at five epochs to detect outbursting CVs - dwarf novae (DN). We also propose to retrieve from the archive globular cluster WFPC2 data, cycles 4 & 5, that were taken over multiple epochs to search for erupting DN. At any given time ~15\ to find ~30\ two epochs. Clusters for which we have three or more epochs should yield >~50\ DN exist in the cores of globular clusters will either support present dynamical theories or strongly constrain new theories that can adequately explain these results. ------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 2] Observations Description ------------------------ We propose to image the cores of two globular clusters (Table 1) in the filter F336W for one orbit each week for five consecutive weeks. The five epochs of NGC 6093 and NGC 6171 will be combined with 2 or 3 archival epochs to yield a very high detection threshold of >~70% in each epoch ~15% image the cluster cores in HAlpha and ``R'' to determine if the DN candidates have an HAlpha excess in quiescence. Globular Cluster Sample Cluster Log(rho_o) (M-m)_o E(B-V) r_core NGC 6093 (M80) 4.79 14.62 0.20 8.9 NGC 6171 (M107) 3.11 14.03 0.33 32.4 Dwarf novae will typically brighten from sim22^nd magnitude to sim18-19^th magnitude in eruption in a globular at (m-M)~15. We will conduct photometry on candidates to ensure that they have the appropriate color and magnitude to be dwarf novae at their host globular cluster distance. Real Time Justification ----------------------- We request that observations of each cluster be separated by 7-10 days to maximize the detection of DN in the entire data set. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6093 STELLAR CLUSTER, RA=16H 17M 02.5S +/- 0.05S, DEC= 2000.0 V = 21.0+/-0.5 GLOBULAR CLUSTER -22D 58' 30" +/- 0.5" B-V = 0.00+/-0.5 2 NGC6171 STELLAR CLUSTER, RA=16H 32M 31.9S +/- 0.05S, DEC= 2000.0 V = 21.0+/-0.5 GLOBULAR CLUSTER -13D 03' 13" +/- 0.5" B-V = 0.0+/-0.5 6460( 3) - 02/09/96 13:50 - [ 4] Visit: 01 Visit Requirements: PCS MODE Fine 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6093 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 2 700S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6093 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 800S ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC6093 WFPC2 IMAGE PC1 F675W CR-SPLIT=NO 3 260S ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC6093 WFPC2 IMAGE PC1 F656N CR-SPLIT=NO 3 1300S ------------------------------------------------------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 5] Visit: 02 Visit Requirements: PCS MODE Fine SAME ORIENTation AS 1 AFTER 1 BY 7D TO 10D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6093 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 2 700S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6093 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 800S ------------------------------------------------------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 6] Visit: 03 Visit Requirements: PCS MODE Fine SAME ORIENTation AS 1 AFTER 2 BY 7D TO 10D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6093 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 2 700S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6093 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 800S ------------------------------------------------------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 7] Visit: 04 Visit Requirements: PCS MODE Fine SAME ORIENTation AS 1 AFTER 3 BY 7D TO 10D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6093 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 2 700S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6093 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 800S ------------------------------------------------------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 8] Visit: 05 Visit Requirements: PCS MODE Fine SAME ORIENTation AS 1 AFTER 4 BY 7D TO 10D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6093 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 2 700S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6093 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 800S ------------------------------------------------------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 9] Visit: 06 Visit Requirements: PCS MODE Fine 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6171 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 2 700S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6171 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 800S ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC6171 WFPC2 IMAGE PC1 F675W CR-SPLIT=NO 3 260S ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC6171 WFPC2 IMAGE PC1 F656N CR-SPLIT=NO 3 1300S ------------------------------------------------------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 10] Visit: 07 Visit Requirements: PCS MODE Fine SAME ORIENTation AS 6 AFTER 6 BY 7D TO 10D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6171 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 2 700S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6171 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 800S ------------------------------------------------------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 11] Visit: 08 Visit Requirements: PCS MODE Fine SAME ORIENTation AS 6 AFTER 7 BY 7D TO 10D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6171 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 2 700S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6171 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 800S ------------------------------------------------------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 12] Visit: 09 Visit Requirements: PCS MODE Fine SAME ORIENTation AS 6 AFTER 8 BY 7D TO 10D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6171 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 2 700S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6171 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 800S ------------------------------------------------------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 13] Visit: 10 Visit Requirements: PCS MODE Fine SAME ORIENTation AS 6 AFTER 9 BY 7D TO 10D 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC6171 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 2 700S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC6171 WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 800S ------------------------------------------------------------------------------------------------------------------------------------ 6460( 3) - 02/09/96 13:50 - [ 14] Summary Form for Proposal 6460 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category BINARIES AND STAR FORMATION ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE Fine PCS MODE Fine SAME ORIENTation AS 1 AFTER 1 BY 7D TO 10D PCS MODE Fine SAME ORIENTation AS 1 AFTER 2 BY 7D TO 10D PCS MODE Fine SAME ORIENTation AS 1 AFTER 3 BY 7D TO 10D PCS MODE Fine SAME ORIENTation AS 1 AFTER 4 BY 7D TO 10D PCS MODE Fine SAME ORIENTation AS 6 AFTER 6 BY 7D TO 10D PCS MODE Fine SAME ORIENTation AS 6 AFTER 7 BY 7D TO 10D PCS MODE Fine SAME ORIENTation AS 6 AFTER 8 BY 7D TO 10D PCS MODE Fine SAME ORIENTation AS 6 AFTER 9 BY 7D TO 10D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W F675W F656N ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC6093 NGC6171 ------------------------------------------------------------------------------------------------------------------------------------